WO2023282057A1 - Storage device, storage medium, and manufacturing method for same - Google Patents

Storage device, storage medium, and manufacturing method for same Download PDF

Info

Publication number
WO2023282057A1
WO2023282057A1 PCT/JP2022/024822 JP2022024822W WO2023282057A1 WO 2023282057 A1 WO2023282057 A1 WO 2023282057A1 JP 2022024822 W JP2022024822 W JP 2022024822W WO 2023282057 A1 WO2023282057 A1 WO 2023282057A1
Authority
WO
WIPO (PCT)
Prior art keywords
magnetic
magnetic wire
wire
pulse
communication
Prior art date
Application number
PCT/JP2022/024822
Other languages
French (fr)
Japanese (ja)
Inventor
博之 粟野
聡 鷲見
Original Assignee
学校法人トヨタ学園
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 学校法人トヨタ学園 filed Critical 学校法人トヨタ学園
Publication of WO2023282057A1 publication Critical patent/WO2023282057A1/en

Links

Images

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/008—Recording on, or reproducing or erasing from, magnetic tapes, sheets, e.g. cards, or wires
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/02—Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/002—Recording, reproducing or erasing systems characterised by the shape or form of the carrier
    • G11B7/003—Recording, reproducing or erasing systems characterised by the shape or form of the carrier with webs, filaments or wires, e.g. belts, spooled tapes or films of quasi-infinite extent
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
    • H01L27/04—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body
    • H01L27/10—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including a plurality of individual components in a repetitive configuration
    • H01L27/105—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including a plurality of individual components in a repetitive configuration including field-effect components
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof  ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/82—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by variation of the magnetic field applied to the device

Definitions

  • This specification discloses a storage device and a storage medium writable by pulsed light for communication, and discloses a method for manufacturing the storage medium.
  • Communication pulsed light A pulsed light that blinks or changes brightness in response to data. It has a high-speed communication speed of 1 Gbps or more, and the light intensity of the bright pulse can be as weak as mW or less.
  • Optical fiber for communication Refers to optical fiber through which pulsed light for communication passes, and collectively refers not only to optical fiber that constitutes infrastructure, but also to optical fiber that is used for optical communication in houses, vehicles, devices, equipment, systems, etc.
  • Pulsed light that has passed through a communication optical fiber Light in which a plurality of types of communication pulsed light with different frequencies or a plurality of types of communication pulsed light with different polarization planes are superimposed may pass through a communication optical fiber.
  • the light obtained by splitting the superimposed light that has passed through the optical fiber for communication according to the wavelength and plane of polarization is referred to as the pulsed light that has passed through the optical fiber for communication.
  • Pulsed light that has passed through an optical fiber for communication is a kind of pulsed light for communication.
  • some short-distance optical communication systems do not use optical fibers, and some pulsed light for communication does not pass through optical fibers for communication.
  • Magnetic wire A wire made of a material whose magnetic domain moves in the material when an electric field is applied (it can be said that a pair of domain walls defining the magnetic domain move). An applied electric field may cause a current to flow, or an applied electric field may cause no current to flow, for example to apply a potential difference across an insulator.
  • Photosensitive magnetic nanowire Among the above-mentioned magnetic nanowires, magnetic domains move when an electric field is applied. When irradiated with a unit bright pulse included in the pulsed light for communication, the magnetization direction of the irradiated region changes in the direction of the external magnetic field.
  • the magnetic wire itself may be formed of a photosensitive material (a phenomenon in which the magnetization direction changes when irradiated with a unit light pulse is called a photosensitive type), or the photosensitive material and the material are magnetically coupled. It may be composed of a combination of magnetic wires that are in contact with each other.
  • the magnetic wire in the latter case may or may not be of the photosensitive type.
  • Storage device Equipped with a photosensitive magnetic wire, an electric field applying device, and a writing device, data transmitted by pulsed light for communication (for example, 1, 1, 1 . . . or 1, 0, 1 . . .
  • a memory device that can write a pattern of time-series changes of bits) into a magnetic nanowire. It is important to store the data, and it may not be necessary to read the data when the data is written. A data reader is not essential to this storage device, as it can be added as needed.
  • Unit light pulse A light pulse with the shortest duration included in the pulsed light for communication, and its duration is called a unit light pulse time.
  • Unit dark pulse A dark pulse with the shortest duration included in pulsed light for communication, and its duration is called a unit dark pulse time.
  • the unit dark pulse time may or may not be equal to the unit light pulse time. Since a plurality of unit dark pulses may be consecutive, the actual dark pulse duration may be a multiple of the unit dark pulse time.
  • Unit pulse collectively refers to a unit light pulse and a unit dark pulse.
  • Non-Patent Document 1 the magnetization direction is reversed by irradiating a part of the magnetic wire with a laser beam.
  • a femtosecond laser with an output of 100 kW needs to be irradiated with a high-intensity laser beam for a very short time in order to use the magnetic term of the laser beam to reverse the electron spin direction.
  • take advantage of The repetitive operation speed of the femtosecond laser is slow, and the data writing speed is 0.1 bps.
  • the magnetization direction cannot be reversed by communication pulsed light with an intensity of mW or less. Also, it cannot support communication speeds of 1 Gbps or more.
  • the magnetization direction of the irradiated area will be the direction of the external magnetic field. It was found that a phenomenon of changing to That is, it was confirmed that when the pulsed light for communication is "bright", the magnetization direction of the irradiated area changes in the direction of the external magnetic field due to the temperature rise effect, and when it is "dark", there is a magnetic wire that does not change the magnetization direction. rice field.
  • a magnetic wire whose magnetization direction after irradiation with a unit light pulse changes from the magnetization direction before irradiation is referred to as a photosensitive magnetic wire.
  • the pulsed light for communication can Disclosed is an apparatus for writing data transmitted by a into a magnetic wire in chronological order. Also disclosed is a storage medium and method of manufacturing the same.
  • thermoelectron current has a spin and becomes a thermal spin current.
  • STT spin transfer torque
  • SOT spin orbit torque
  • the storage device disclosed in this specification includes a photosensitive magnetic wire, an electric field applying device, and a writing device.
  • a photosensitive magnetic wire When a photosensitive magnetic wire is irradiated with a unit light pulse included in optical pulse light for communication, the magnetization direction of the irradiated region changes in the direction of the external magnetic field, and when an electric field is applied, the magnetic domain moves in the length direction.
  • the movement of the magnetic domain here means that the magnetic wire itself is stationary and the magnetic domain moves within the stationary magnetic wire.
  • the electric field applying device applies an electric field to the magnetic wire. In some cases, the application of an electric field causes a current to flow through the magnetic wire, but in some cases, the electric field is applied but the current does not flow, for example, because a potential difference is applied through an insulator.
  • the domain migration speed can be adjusted by electric field strength or current density.
  • the writing device changes the magnetization direction of the irradiated area of the photosensitive magnetic wire to the direction of the external magnetic field by using the unit light pulse included in the pulsed light for communication and the external magnetic field. That is, when the pulsed light for communication is bright, the temperature is raised by being irradiated with the bright pulsed light, and the magnetization direction of the irradiated region is changed to the direction of the external magnetic field. In some cases, the magnetization direction is changed using the above-described thermal spin current. On the other hand, when the pulsed light for communication is dark (the intensity of the pulsed light is zero or weak), the temperature is not raised to a temperature that changes the magnetization direction.
  • a technique of directly irradiating the photosensitive magnetic nanowire with pulsed light may be used, or a technique of irradiating a material magnetically coupled to the magnetic nanowire with pulsed light may be used. may be used. If the material is heated by irradiation with a unit light pulse and a phenomenon occurs in which it changes in the direction of the external magnetic field, the phenomenon of changing the magnetization direction is propagated to the magnetic wire and the magnetization of a part of the length of the magnetic wire is generated. The direction can be reversed in the direction of the external magnetic field.
  • the magnetization direction must be oriented in a direction different from that of the external magnetic field before it is changed to the direction of the external magnetic field.
  • the configuration for this purpose is not particularly limited, and the entire length of the magnetic nanowire may be magnetized in the different directions described above, or the magnetic nanowire may be passed through an initial magnetization device prior to passing through the writing device, The initial magnetization device may be magnetized in the different directions described above.
  • changing the magnetization direction from the direction different from the external magnetic field to the direction of the external magnetic field is sometimes referred to as reversing the direction of the external magnetic field.
  • magnetic domain movement speed > "unit reversal magnetic domain length/(unit bright pulse time + unit dark pulse time)".
  • magnetic domain movement velocity means the average movement velocity of the magnetic domains calculated for the total time obtained by integrating the unit bright pulse time and the unit dark pulse time.
  • the magnetic domain migration speed changes within the unit light pulse time (for example, when an electric field is intermittently applied to the magnetic wire, the magnetic domain moves intermittently), or when the magnetic domain migration speed changes within the unit dark pulse time, It refers to the average speed of movement within the total time.
  • this speed condition is satisfied, a non-reversed magnetic domain remains between two adjacent reversed magnetic domains across a unit minimum non-reversed magnetic domain, and the non-reversed magnetic domain does not disappear.
  • the unit reversal magnetic domain length here refers to the distance along the length of the magnetic wire in the region where the magnetization direction is reversed by the irradiation of the unit light pulse. It may differ from the unit non-inverted magnetic domain length, which will be described later, and may also differ from the unit magnetic domain length. As used herein, length refers to the distance along the length of the magnetic wire unless otherwise specified.
  • a reading device can be added to this storage device.
  • the reader requires electrical signal processing, and when the communication speed of the pulsed light for communication is high, it is difficult to complete the reading process within the light-dark change period.
  • a plurality of magnetic wires and a plurality of magnetization direction detectors can be used simultaneously to substantially increase the reading speed.
  • the writing speed and the actual reading speed can be matched.
  • data transmitted by the communication pulse light can be relayed, transmitted, and transferred to an external device such as a hard disk.
  • the first transfer magnetic wire stores the 1st, 4th, 7th, . . . bits
  • the second transfer magnetic wire stores the 2nd, 5th, 8th, .
  • the 3rd, 6th, 9th, . . . bits can also be stored in the third transfer magnetic wire. Also in this way, the time available for reading data can be lengthened.
  • the technology disclosed in this specification newly provides various storage media.
  • a storage medium with features such as a condenser lens, heat insulation, heat sink, etc. in relation to the temperature rise by a unit light pulse, and provide a plurality of magnetic wires to store data in duplicate or in a distributed manner.
  • the present invention provides a storage medium that holds multiple magnetic wires, and provides a new structure that realizes a plurality of magnetic wires.
  • a storage medium that realizes an M-RAM structure by means of a magnetization direction detection device and a transistor or the like that is turned on/off depending on the magnetization direction.
  • a method of manufacturing a storage medium is also provided.
  • the phenomenon of directly or indirectly reversing the magnetization direction of a part of the length of the magnetic wire due to the temperature rise by the pulsed light for communication (more precisely, the unit light pulse), and the magnetic domain
  • the pulsed light for communication more precisely, the unit light pulse
  • the magnetic domain Using a combination of phenomena that move along the length of the magnetic nanowire, we form an array of reversed magnetic domains corresponding to the bright pulse and non-reversed magnetic domains corresponding to the dark pulse in the magnetic nanowire, and data transmitted by the pulsed light for communication. can be stored in the magnetic wire. Since data is directly or indirectly written in the magnetic wire by the pulsed light for communication itself, it is possible to cope with high-speed communication using light. Also, since no photoelectric conversion process is required, the amount of power required to operate the storage device is reduced.
  • FIG. 2 is a schematic plan view of the storage device of the embodiment;
  • FIG. 2 is a schematic cross-sectional view of the storage device in FIG. 1;
  • 2 is a timing chart for explaining the operation of the storage device in FIG. 1;
  • FIG. 4 is a diagram for explaining the relationship between a temperature rise region, an external magnetic field effective region, and a reversed magnetic domain;
  • FIG. 4 is a diagram for explaining the relationship between pulsed light and magnetic domains in a magnetic nanowire;
  • FIG. 10 is a diagram for explaining another example of the external magnetic field generator;
  • FIG. 2 is a schematic cross-sectional view of the storage medium of the example;
  • FIG. 4 is a diagram for explaining a magnetic wire, a temperature rising region, and a reversed magnetic domain
  • FIG. 4 is a diagram for explaining a temperature rise region and reversed magnetic domains when a heat sink is present
  • FIG. 10 is a diagram for explaining another example of a temperature rising region and reversed magnetic domains when a heat sink is present
  • 4A and 4B are diagrams for explaining the operation of the storage device of the embodiment
  • FIG. 2 shows the relationship between the power in writing and the voltage of the read signal. 2 shows the relationship between the current density of a magnetic nanowire and the magnetic domain migration speed.
  • the relationship between reception sensitivity and transfer speed (transfer rate) is shown.
  • the relationship between transfer speed (transfer rate) and power consumption required for data transfer is shown.
  • FIG. 1 is a schematic perspective view of a storage device using four optical fibers
  • FIG. FIG. 18 is a surface view of the storage device of FIG. 17
  • FIG. 17 shows the relationship between the irradiation area, the external magnetic field effective area, and the magnetic wire in the storage device of FIG.
  • FIG. 4 is a perspective view of another example of a storage device that utilizes four optical fibers
  • FIG. 21 is a rear view of the storage device of FIG. 20
  • FIG. 21 is a surface view of the storage device of FIG. 20
  • FIG. 20 shows the relationship between the irradiation area, the external magnetic field effective area, and the magnetic wire in the storage device of FIG.
  • FIG. 4A and 4B are a cross-sectional view and a plan view of a storage device of Example 1; 11A and 11B are a cross-sectional view and a plan view of a storage device of Example 2; 13A and 13B are a cross-sectional view and a plan view of a storage device of Example 3;
  • FIG. 11 is a perspective view of a storage device of Example 4;
  • FIG. 11 is a cross-sectional view of a storage device of Example 5;
  • FIG. 11 is a perspective view of a storage device of Example 6;
  • FIG. 11 is a plan view of a storage device of another example 7;
  • FIG. 11 is a plan view of a storage device of Example 8;
  • FIG. 11 is a plan view of a storage device of Example 9;
  • FIG. 11 is a plan view of a storage device of another example 10; FIG. 11 is an operation explanatory diagram of the storage device of another example 10; FIG. 11 is a cross-sectional view of a storage device of Example 11; FIG. 12 is a cross-sectional view of a storage device of Example 12; FIG. 21 is a cross-sectional view of a storage device of Example 13; FIG. 21 is a cross-sectional view of a storage device of another example 14; FIG. 21 is a schematic perspective view of a storage device of another example 15;
  • FIG. 1 shows a plan view of a storage device 1 of an embodiment, comprising a photosensitive magnetic wire, an electric field applying device, a writing device, a reading device (reproducing device), and a switching device.
  • a photosensitive magnetic wire two photosensitive magnetic wires 2A and 2B, whose magnetic wires themselves are photosensitive, are alternately used.
  • the photosensitive magnetic wires 2A and 2B are abbreviated as magnetic wires 2A and 2B.
  • the electric field application device includes two DC power supply units 15A and 15B, two switches 14A and 14B, two non-magnetic conducting wires 4A and 4B, and a common non-magnetic conducting wire 4.
  • FIG. 1 shows a plan view of a storage device 1 of an embodiment, comprising a photosensitive magnetic wire, an electric field applying device, a writing device, a reading device (reproducing device), and a switching device.
  • two photosensitive magnetic wires 2A and 2B whose magnetic wires themselves are photosensitive, are alternately used.
  • the writing device includes an external magnetic field generator 6 for initial magnetization and an external magnetic field generator 8 for writing, and utilizes an irradiation range 10 of pulsed light that has passed through a communication optical fiber.
  • the reading device includes a sensor array 12A for simultaneously reading multiple-bit data written on the magnetic wire 2A and a sensor array 12B for simultaneously reading multiple-bit data written on the magnetic wire 2B.
  • TMR sensors whose resistance value changes depending on the magnetization direction of the magnetic wire are arranged.
  • the storage device of the embodiment also includes a control device 16, which transfers or relays data transmitted by the pulsed light for communication to a hard disk device HDD17.
  • the control device 16 controls the operation of the power supply devices 15A and 15B and the switches 14A and 14B based on the clock signal contained in the communication pulse light, and transmits the data detected by the sensor arrays 12A and 12B to the HDD 17 .
  • the magnetic wires 2A and 2B are also part of the electric field applying device, the writing device and the reading device, respectively. Also, the control device 16 and the switches 14A, 14B and the like constitute a switching device.
  • FIG. 2 shows a cross-sectional view in which the above members are formed on a polycarbonate substrate 18.
  • TMR sensors are arranged in each of the sensor rows 12A and 12B, and each sensor is connected to the control device 16, but the illustration of a part of the connection relationship is omitted in FIG.
  • reference numeral 19 is a dielectric
  • sensor arrays 12A and 12B, magnetic wires 2A and 2B, external magnetic field generating films 6 and 8, etc. are fixed on a substrate 18 and insulated from each other.
  • the magnetic wire 2A is preferably made of an RE-TM ferrimagnetic material, and in this example, a TbCoFe alloy was used.
  • the material is not limited to this, and may be an alloy based on a rare earth element and a 3d transition element, or may be a multilayer film composed of a rare earth element and a 3d transition metal element.
  • ferrimagnetic materials and are perpendicular magnetization films whose magnetization easy axis is perpendicular to the film surface.
  • a multi-layered film composed of a 3d transition metal and a noble metal, which serves as a perpendicular magnetization film, may also be used.
  • These magnetic wires not only move their magnetic domains when an electric field is applied, but also a phenomenon in which the magnetization direction of the irradiated region changes and is fixed in the direction of the external magnetic field when irradiated with a unit light pulse included in the pulsed light for communication. occurs.
  • the magnetic wire 2A is made of a photosensitive material and is itself a photosensitive magnetic wire.
  • a spin transfer torque (STT) is necessary for the domain wall to move with current, and it is preferable to have a large spin-orbit torque (SOT) due to the heterostructure of the magnetic layer and the heavy metal layer.
  • STT spin transfer torque
  • SOT spin-orbit torque
  • the spin of electrons flowing in the magnetic material drives the domain wall
  • the flow of electrons flowing in the heavy metal layer penetrates the magnetic layer due to the heterointerface and drives the domain wall.
  • a magnetic nanowire is irradiated with a laser beam, it is locally heated, and a large temperature gradient is instantaneously generated in the in-plane and vertical directions of the film, and a large amount of thermionic electrons flow along this temperature gradient. This thermal electron becomes a thermal spin current with spin.
  • Recording magnetic domains can be easily formed by STT and SOT generated by this thermal spin current. Recording magnetic domains can be formed even with a small laser power. In order to effectively utilize this thermal spin current, it is important to select the combination of materials and the thickness of the magnetic layer and the heavy metal layer.
  • the magnetic wire is thin enough to transmit light.
  • the magnetic nanowires are adiabatic, in addition to confining the light. It is advantageous to have an adiabatic structure including the substrate. For example, glass or plastic with low thermal conductivity is good for the substrate. Also in the case of a Si substrate, it is preferable to have a dielectric film of 100 nm or more on the substrate surface.
  • the magnetic domains and domain walls in the magnetic wire 2A move in the same direction as the current.
  • the movement speed of the magnetic domain and the domain wall can be adjusted by the current value, and in this embodiment, a current value that moves at a speed of 2500 m/sec is applied.
  • capital letters are used for subscripts in order to distinguish between a plurality of magnetic wires. Subscripts are omitted when describing phenomena common to a plurality of magnetic wires.
  • An external magnetic field generator (magnetic field generating film in the embodiment) 6 for initial magnetization applies a downward magnetic field having a strength greater than the coercive force of the magnetic wire 2 at room temperature to the magnetic wire 2 .
  • the external magnetic field generator 6 is magnetically coupled to the left end of the magnetic wire 2, and aligns the magnetization directions of the magnetic domains moving from left to right in the magnetic coupling region downward.
  • An external magnetic field generator (magnetic field generating film in the embodiment) 8 for writing is an upward magnetic field having a strength smaller than the coercive force of the magnetic wire 2 at room temperature but larger than the coercive force of the magnetic wire 2 at elevated temperature. is added to the magnetic wire 2.
  • the external magnetic field generator 8 is arranged downstream of the external magnetic field generator 6 in the movement direction of the domain wall. do.
  • the external magnetic field generator 8 is arranged inside the irradiation area 10 of the pulsed light for communication, and the area heated by the irradiation of the unit light pulse of the pulsed light for communication is magnetically coupled with the external magnetic field generator 8 .
  • the magnetization direction of the passing magnetic domain When the magnetic domain passes through the region magnetically coupled with the external magnetic field generator 8, if the temperature is raised by the bright pulse, the magnetization direction of the passing magnetic domain must be reversed upward and the temperature must be raised by the dark pulse. In this case, the magnetization direction of the passing magnetic domain is not reversed and is maintained downward. As a result, the magnetization direction of the magnetic domains passing through the magnetic coupling region with the external magnetic field generator 8 during bright pulse irradiation becomes upward, and the magnetization direction of the magnetic domains passing through the magnetic coupling region during dark pulse irradiation becomes downward.
  • data are written corresponding to the time-series change pattern of light and dark.
  • the external magnetic field for writing is abbreviated as the external magnetic field unless otherwise specified.
  • the reversal temperature can be selected according to the material of the magnetic wire, and the heat dissipation or heat insulation of the magnetic wire can be adjusted by the elements arranged around the magnetic wire. ) in which the temperature of the magnetic wire rises to the reversal temperature.
  • the time from the start of light pulse irradiation until the temperature is raised to the inversion temperature is referred to as the required temperature rise time.
  • the required temperature rise time it can be set so that the temperature rises to the reversal temperature and the reversal occurs when 38 psec has elapsed from the start of irradiation of the bright pulse.
  • the required temperature rise time is 38 psec. After the required temperature rise time has elapsed, the length of the reversed magnetic domain increases with the movement of the domain wall until the end of the light pulse.
  • External magnetic field Unless otherwise specified, this refers to the external magnetic field for writing, not the external magnetic field for initial magnetization.
  • External magnetic field effective region A region where the external magnetic field for writing that reverses the magnetization direction is dominant.
  • Temperature rising region A region in which the temperature is increased to the inversion temperature or higher. It expands with the elapsed time of the bright pulse and disappears by cooling within the period of the unit dark pulse.
  • Required temperature rise time The time from the start of light pulse irradiation until the temperature is raised to the inversion temperature.
  • the present technology utilizes a phenomenon in which the temperature is raised by bright pulse light and reversed in the direction of the external magnetic field, the magnetization direction is reversed in the region where the temperature rise region and the external magnetic field effective region overlap.
  • the magnetization direction of the magnetic wires in the external magnetic field effective region reverses almost all at once when the temperature rise region expands to include the external magnetic field effective region. do.
  • the distance along the length of the magnetic wire in which the regions are simultaneously reversed is called the "simultaneous reversal length.”
  • the length of the reversed magnetic domain increases along with the expansion of the temperature rise region.
  • the unit reverse magnetic domain length corresponding to the unit bright pulse in this case is determined by the size of the temperature rising region. Since the expansion speed of the temperature rising region is usually equal to or higher than the magnetic domain moving speed, the unit reversal domain length is determined by the size of the temperature rising region at the end of the bright pulse.
  • the temperature rising region expands to include the external magnetic field effective region.
  • the single pulse time of the pulsed light for communication that irradiates the irradiation area 10 is 40 psec, and has a communication speed of 25 Gbps.
  • FIG. 4 shows the temperature change when the irradiation start time of the unit bright pulse is set to zero.
  • the region 40-8 heated to the reversal temperature is narrow, and the external magnetic field generator 8 does not reverse the magnetization direction upward.
  • the region heated up to the inversion temperature increases with the passage of time.
  • the temperature of the region magnetically coupled with the external magnetic field generator 8 rises above the reversal temperature. That is, the region magnetically coupled with the external magnetic field generator 8 is included in the temperature rising region 40-38.
  • the magnetization directions of the regions magnetically coupled to the external magnetic field generator 8 are reversed upward almost all at once after 38 psec from the start of irradiation of the bright pulse.
  • the pulse time is 40 psec, and the bright pulse lasts for 2 psec after reversal, during which the magnetic domain moves.
  • the magnetic wire is supplied with a current value that causes the domain wall to move at a speed of 2500 m/sec, so that the reversed magnetic domain expands by 5 nm in 2 psec.
  • a 105 nm long reversed magnetic domain is formed by a unit light pulse.
  • the unit reversal magnetic domain length in this example is 105 nm.
  • the unit reversal domain length simultaneous reversal length + domain movement speed ⁇ (after the required temperature rise time light pulse duration).
  • the length of the temperature rising region at the end of the unit bright pulse is the unit reversal magnetic domain length.
  • the length of the temperature rise region at the end of the unit light pulse is the unit reversal domain length.
  • (2) of FIG. 3 shows an example of time-series change in brightness of pulsed light for communication
  • 30A indicates the shortest dark pulse
  • 32A indicates the shortest bright pulse. Both pulse times are equal, 40 psec in this embodiment.
  • 30B indicates a dark pulse consisting of two consecutive shortest dark pulses
  • 32B indicates a bright pulse consisting of two consecutive shortest bright pulses.
  • it shows a time-series change of "bright, dark, bright, bright, dark, dark, bright, dark", which is an example of data referred to in this specification.
  • FIG. 5 shows the data and the relationship between magnetic domain and magnetization direction in the magnetic wire.
  • (1) shows the case where the pulsed light changes "bright/dark/bright/dark"
  • (1a) shows the relationship between the magnetic domains in the magnetic nanowire and the magnetization direction.
  • a hatched magnetic domain indicates a reversed magnetic domain that is reversed in the direction of the external magnetic field
  • an unhatched magnetic domain indicates a non-reversed magnetic domain that is not reversed by the external magnetic field.
  • 51a indicates the reversed magnetic domain formed by the bright pulse 51
  • 52a indicates the remaining non-reversed magnetic domain corresponding to the dark pulse 52
  • 53a indicates the reversed magnetic domain formed by the bright pulse 53
  • 54a indicates the dark pulse 54.
  • a period T55 shown in FIG. 5(1) is a pulse time (40 psec in this embodiment).
  • a period T56 is a required temperature rise time (38 psec in this embodiment).
  • the period T57 corresponds to 38-40 psec in FIG.
  • the reversed magnetic domain 51a is formed within the period T57.
  • the length of the reversed magnetic domain 51a is equal to the simultaneous reversal length (100 nm in FIG. 4 in this embodiment)+the magnetic domain movement distance within the period T57 (5 nm in this embodiment), and the unit reversed magnetic domain length in this embodiment is 105 nm. be.
  • the period T58 corresponds to a period during which the magnetic domain is not reversed, and the length of the period is equal to the pulse time plus the required temperature rise time.
  • the length of the non-reversal region 52a is (pulse time+required heating time) ⁇ magnetic domain moving speed ⁇ “simultaneous reversal length”, which is 95 nm in this embodiment.
  • the unit reversal magnetic domain length in this example is 105 nm, and the unit non-reversal magnetic domain length is 95 nm, which are different.
  • FIG. 5(2) shows a case where "dark/dark” continues.
  • the period T'58 corresponds to the period during which the magnetic domain is not reversed by successive dark pulses, and the length of the corresponding non-reversed magnetic domain is (pulse time x 2 + required temperature rise time) x magnetic domain movement speed - "simultaneous reversal length". , which is 195 nm in this embodiment.
  • FIG. 5(3) shows a case where "bright/bright" continues.
  • the period T'57 corresponds to the period in which the magnetic domain is reversed by successive bright pulses, and the length of the corresponding reversed magnetic domain is equal to the simultaneous reversal length (100 nm in this embodiment) + the magnetic domain movement distance within the period T'57 ( 105 nm in this embodiment) and 205 nm in this embodiment.
  • the domain wall position changes depending on the light and dark change pattern, and although it does not become constant, it does not deviate greatly.
  • the position P1 is , in the magnetic domain corresponding to the first pulse 51, position P2 in the magnetic domain corresponding to the second pulse 52, position P3 in the magnetic domain corresponding to the third pulse 53, position P4 in It is in the magnetic domain corresponding to the fourth pulse 54 .
  • a sensor for detecting a value that changes according to the magnetization direction of the first magnetic domain is arranged at position P1
  • a second identical sensor is arranged at position P2
  • a third identical sensor is arranged at position P3. If a fourth identical sensor is arranged at the position P4, the magnetization directions of the four magnetic domains can be read in parallel.
  • 1 bit can be written in 40 psec.
  • 100 psec or more is required to detect the magnetization direction by a sensor that detects a value that changes according to the magnetization direction (for example, Tunneling Magneto Resistive, TMR). If a plurality of sensors can simultaneously read a plurality of bits, it is possible to solve the problem that the reading process by each sensor is slow and cannot keep up with the communication speed.
  • TMR Tunneling Magneto Resistive
  • Unit magnetic domain length Pulse time x magnetic domain moving speed.
  • Unit reversal domain length The length of a unit reversal domain formed by a unit light pulse. When the reversed magnetic domains are formed, it takes time to raise the temperature, a region that reverses almost all at once is formed, and the temperature rise region has a spread.
  • Unit non-inverted magnetic domain length The length of a unit non-inverted magnetic domain remaining in response to a unit dark pulse. Its length is (2 ⁇ pulse time) ⁇ domain migration speed ⁇ unit reversal domain length.
  • the length of one magnetic domain is 95 nm or 105 nm.
  • the length of each magnetic domain does not necessarily equal the unit magnetic domain length.
  • data is written in 16 magnetic domains of the magnetic wire 2A for 16 consecutive pulses.
  • data is written into 16 magnetic domains of the magnetic wire 2B.
  • the time required for each process is "40 psec ⁇ 16".
  • the magnetization directions of the 16 magnetic domains of the magnetic wire 2A are read while data is written to the 16 magnetic domains of the magnetic wire 2B.
  • Processing in each sensor requires 40 psec or more, but since 16-bit data is read in parallel, the 16-bit data can be detected within "40 psec x 16" and the read data is stored in the HDD 17. can be relayed. Even if it takes time to read the data by each sensor, since 16 bits are read in parallel, the data can be relayed to the HDD 17 at the optical communication speed.
  • FIG. 3 shows a timing chart. (1) and (2) show the light and dark patterns of pulsed light for communication.
  • the clock signal (1) and the data signal (2) are shown separately for the convenience of understanding. sent.
  • the clock signal is shown as one bit, but in reality, the clock signal is a multi-bit signal conforming to a predetermined protocol.
  • the switch 14A is turned on at a predetermined timing (a clock signal is used to determine the arrival of the predetermined timing) to energize the magnetic wire 2A and start moving the domain wall of the magnetic wire 2A (see (3)). ). At this time, the magnetic wire 2B does not move the domain wall (see (5)). A bright and dark pattern of the pulsed light for communication is written in the longitudinal direction on the magnetic wire 2A whose domain wall moves. After 16 ⁇ 40 psec has passed, the magnetic wire 2A is stopped after being energized for a predetermined time (34 in (3)). The predetermined time 34 is set to the time required for the bit that has passed the external magnetic field generator 8 last to move to the position facing the most upstream sensor in the sensor array 12A.
  • a predetermined timing a clock signal is used to determine the arrival of the predetermined timing
  • the 16 magnetic domains are stopped corresponding to the 16 sensors.
  • the magnetization directions of 16 magnetic domains are read concurrently during the period 36 and the read data are sent to the HDD 17 .
  • Data may be sent to the HDD 17 in parallel or serially.
  • the switch 14B After writing 16-bit data to the magnetic wire 2A, the switch 14B is turned on to energize the magnetic wire 2B and start moving the domain wall of the magnetic wire 2B (see (5)). A light-dark pattern of the pulsed light for communication is written in the longitudinal direction on the magnetic wire 2B in which the domain wall moves.
  • the current is supplied for a predetermined time (38 in (5)), and then the current is stopped.
  • the predetermined time 38 is set to the time required for the bit that has passed the external magnetic field generator 8 last to move to the position facing the most upstream sensor in the sensor array 12B.
  • the 16 magnetic domains are stopped corresponding to the 16 sensors.
  • (1) Data can be written with a weak communication pulse light of mW or less.
  • (2) Data can be written by communication pulsed light whose brightness changes at high speed (1 Gbps or more).
  • the problem that the data reading speed is slower than the data transmission speed can be dealt with by a technique of reading a plurality of bits in parallel.
  • Multiple magnetic wires are selectively used in chronological order for data storage while multiple bits are read in parallel. Such features will be demonstrated, and a new world of data storage will be realized.
  • Magnetic wires are not limited to RE-TM ferrimagnetic material. A single light pulse heats up to the reversal temperature, and when the reversal temperature is exceeded, the material is reversed in the direction of the external magnetic field, and the magnetic domain (domain wall) moves when an electric field is applied. Available if available.
  • Magnetic wires in which current flows by applying an electric field A magnetic wire that does not flow even when an electric field is applied may be used.
  • the magnetic wire is not limited to a magnetic wire in which the magnetic domain wall moves in the longitudinal direction when an electric current is applied in the longitudinal direction of the magnetic wire.
  • a magnetic wire may be used in which the magnetic domain wall moves longitudinally when an electric field is applied along the cross section of the magnetic wire.
  • the number of magnetic wires is not limited to two, and may be three or more.
  • the number of bits that can be read simultaneously is not limited to 16, and may be larger or smaller.
  • the magnetization direction detection sensor is not limited to a tunnel current detection sensor, and may be a magnetic sensor, a voltage sensor, a current sensor, or an optical sensor.
  • the unit light pulse time and the unit dark pulse time may differ depending on the optical communication protocol. Even in that case, if there is a relationship of "magnetic domain migration speed">"unit reversed magnetic domain length/(unit bright pulse time + unit dark pulse time)", two adjacent magnetic domains sandwiching the minimum non-reversed magnetic domain corresponding to the unit dark pulse A non-reversed magnetic domain remains between the reversed magnetic domains, and the non-reversed magnetic domain does not disappear. (9) When writing data to the magnetic wire, the magnetic domain migration speed may change. For example, an electric field may be intermittently applied to the magnetic wire to intermittently move the domain wall.
  • the magnetic domain migration speed described in (8) above refers to the average domain wall migration speed calculated for the total time of the unit bright pulse time and the unit dark pulse time. (10) Instead of using a magnetic material whose magnetization direction changes to the direction of the external magnetic field when heated to the reversal temperature or higher, the It is possible to use a magnetic material that is fixed in the direction of . (Second embodiment)
  • the external magnetic field generator 8A for writing includes a magnetized film 8e that generates an upward magnetic field and magnetized films 8a, 8b, 8c, 8d, and 8f that generate a downward magnetic field disposed around it.
  • the domain length decreases, the amount of data that can be stored in the same length of magnetic wire increases. Also, the moving speed of the domain wall can be reduced.
  • an external magnetic field generator 8 for writing is composed of a DC power source 8a and a non-magnetic lead wire 8b.
  • the conducting wire 8b intersects the magnetic wires 2A and 2B in an orientation perpendicular to the length direction of the magnetic wires 2A and 2B in the irradiation region 10 .
  • An upward magnetic field is generated in the region to the right of the conductor 8b by the current flowing through the conductor 8b.
  • An upward external magnetic field can reverse the magnetization directions of the magnetic wires 2A and 2B upward. It becomes the external magnetic field generator 8 for writing.
  • the entire length of the magnetic wires 2A and 2B is magnetized downward (magnetized).
  • the magnetic wires 2A and 2B may be placed in a downward magnetic field having a strength equal to or greater than the coercive force.
  • a downward magnetic field is generated in the region on the left side of the conductive path 8b. Since the magnetic wires 2A and 2B are initially directed downward, no particular problem occurs.
  • FIG. 8 shows a cross section of the substrate 18, the magnetic wire 2, and the like.
  • This storage medium comprises, from the incident side of the pulsed light 9 for communication, a light intensity enhancing dielectric film 84, a thin protective film 83, a magnetic wire 2, a light intensity enhancing dielectric film 82, a metal reflecting film 81, and a substrate 18 in this order. Laminated.
  • the light intensity enhancing dielectric film 84 is formed in the irradiation area of the communication pulsed light 9, but is not formed in the area where the magnetization direction detection sensor array 12 is arranged. At the arrangement position of the detection sensor array 12 for the magnetization direction, the distance between the detection sensor 12 and the magnetic wire 2 is reduced to increase the detection sensitivity.
  • the metal reflective film 81 reflects the pulsed light 9 that has passed through the magnetic wire 2 toward the magnetic wire 2 so that the weak (mW or less) pulsed light can raise the temperature of the magnetic wire 2 .
  • the light intensity enhancing dielectric film 84 and the light intensity enhancing dielectric film 82 confine the communication pulsed light 9 between them so that the weak communication pulsed light can raise the temperature of the magnetic wire 2 .
  • FIG. 9 shows a case where one magnetic wire 2 is arranged in an irradiation area 10 of pulsed light for communication.
  • a curve 91 shows the temperature distribution in the transverse direction of the magnetic wire
  • a curve 92 shows the temperature distribution in the longitudinal direction of the magnetic wire.
  • FIG. 10 shows an example in which a heat sink 104 is added to the left side of the temperature raising region 40.
  • FIG. 10 shows an example in which a heat sink 104 is added to the left side of the temperature raising region 40.
  • curve 102 the temperature distribution in the longitudinal direction of the magnetic wire is asymmetrical, and the temperature drops sharply on the left side of the center of the irradiation area 10 .
  • the temperature rising region 40 extends to the right from the center, but hardly extends to the left. As a result, the length of the unit reversed magnetic domain 103 is shortened. (Seventh embodiment)
  • FIG. 11 shows an example in which a heat sink 104 is added to the left side of the temperature raising region 40 and an external magnetic field effective region 118 is formed in a partial region on the right side. As a result, the length of the unit reversal magnetic domain 113 is further shortened. (Eighth embodiment)
  • FIG. 12 shows an embodiment in which the operating frequency of the magnetization direction detector 12 and the flashing frequency of the pulsed light 9 for communication are the same.
  • one magnetic wire 2 may be used.
  • a current is supplied from the power source 15 so that the magnetic domain moves from left to right in the magnetic wire 2, and the magnetization direction of the magnetic wire 2 is oriented downward by the magnetization film 6 for initialization at the most upstream portion.
  • the pulsed light 9 for communication that has passed through the optical fiber 123 is condensed by the condensing lens 122 and irradiates the region magnetically coupled with the magnetized film 8 for writing.
  • the size of the temperature rising region at the end of the unit light pulse and the size of the external magnetic field effective region are in a substantially equal relationship.
  • the magnetic domain that was a bright pulse at the time of passing through the external magnetic field effective region is heated and reversed in the magnetization direction (upward) of the magnetization film 8 . Since the magnetic domain which is a dark pulse at the time of passing through the external magnetic field effective region is not heated up, it does not reverse the magnetization direction (upward) of the magnetized film 8 and maintains the downward magnetization direction.
  • the magnetization direction detection device 12 detects whether the magnetization direction is upward or downward for each passing magnetic domain, and outputs the detection results in time series. According to this device, the data transmitted by the pulsed light 9 for communication can be stored in one magnetic wire 2, and the recorded data can be reproduced.
  • the magnetic wire 2 of this embodiment is a photosensitive magnetic wire.
  • FIG. 13 shows the power required for writing on the horizontal axis and the voltage of the read signal on the vertical axis in the embodiment of FIG. It shows that a signal with a detectable intensity can be read as long as the power is -35 dBm or more. Note that this experiment was performed at 1 Gpbs.
  • FIG. 14 shows the applied current density on the horizontal axis and the magnetic domain migration speed obtained on the vertical axis in the embodiment of FIG. If the current density is increased, the magnetic domain movement speed increases, and high-speed movement of 5000 m/sec or more can be realized.
  • the horizontal axis indicates the reception sensitivity
  • the vertical axis indicates the data transfer rate.
  • Range 152 indicates the case of conventional optical communication, and range 151 is the case of the present technology. This technique provides performance improvements.
  • the horizontal axis indicates the data transfer speed, and the vertical axis indicates the power consumption required for the transfer.
  • a straight line 162 indicates the case of conventional optical communication, and a straight line 161 indicates the case of the present technology. This technology enables a dramatic reduction in power consumption.
  • the heat treatment laser beam is condensed at the central portion in the width direction of the magnetic wire, and the condensing portion is moved in the length direction of the magnetic wire. If this heat treatment is carried out in advance, the coercive force at the central portion of the magnetic wire is reduced, and the magnetic domain wall at the central portion of the wire can be driven at a low current density.
  • the domain wall drive current density with a pulse width of 3 ns before laser irradiation was 3 ⁇ 10 11 A/m 2 and the domain wall moving speed was 1900 m/sec, while the current density after laser irradiation was 0.5 ⁇ 10 11 A/m 2 .
  • the domain wall motion speed was increased to 3000m/sec.
  • a similar phenomenon was also confirmed by applying a large current density to the magnetic wire in advance. That is, when a current density of 40 ⁇ 10 11 A/m 2 was applied to the same magnetic wire as above for 1 ⁇ sec, the coercive force at the center of the magnetic wire decreased to 680 Oe.
  • the domain wall driving current density was reduced to 1.8x10 11 A/m 2 and the domain wall moving speed was increased to 2200m/sec. Even if 3x10 11 A/m 2 domain wall drive current pulses with a normal pulse width of 3 nsec are applied to the magnetic wire 100 times, the coercive force at the center of the magnetic wire remains 850 Oe, so a long pulse current with a large current density is applied in advance. It was found that this is effective for improving the domain wall motion velocity and reducing the driving current density. This finding is of great importance to the present proposal.
  • FIG. 17 shows storage for four optical fibers 171a, 171b, 171c, 171d.
  • four sets of storage devices are formed on the light receiving surface (surface) of the storage device 172 .
  • the suffixes of lowercase letters of the alphabet indicate the correspondence, and for example, 10a is the irradiation range for the optical fiber 171a.
  • four magnetic wires 2A, 2B, 2C and 2D are used for one optical fiber.
  • data written to one magnetic wire 2A can be read while data is written in order to three magnetic wires, for example, magnetic wires 2B, 2C, and 2D. and the time limit on reading is relaxed.
  • the number of magnetic wires used in one optical fiber is not limited, and may be 11 as shown in FIG. 19, or may be more.
  • a method of use is possible in which all of the magnetic wires 2A to 2K are magnetized downward prior to use, and data is stored in a new storage medium after data is stored in all of the magnetic wires 2A to 2K.
  • a magnetic field generator for initial magnetization is unnecessary.
  • the conductive wire 4 and the external magnetic field generator 8 for writing may be arranged.
  • condensing lenses 22a, 22b, 22c, and 22d can be arranged on the front surface (irradiation surface of pulsed light) of a transparent substrate 173, and magnetic wires 2 and the like can be arranged on the back surface. It is possible. In this case, if polycarbonate is used for the transparent substrate, the magnetic domain movement speed is increased. Moreover, since it is a resin substrate, it can be manufactured at a low cost by the nanoimprint technology described below.
  • FIG. 23 shows the relationship between the temperature rising region 40, the magnetic wire 2, and the non-magnetic wire 4.
  • the external magnetic field effective area is wide.
  • the boundary between the magnetic wire 2 and the non-magnetic wire 4 is located slightly inside the temperature rising region 40 .
  • a wiring pattern is formed by RE-TM not only in the magnetic wire 2 but also in the formation range of the non-magnetic conductive wire 4 .
  • the portion to be the non-magnetic conductor 4 is subjected to ion implantation treatment to lose the ability to move the magnetic domain.
  • the boundary between the magnetic wire 2 and the non-magnetic wire 4 can be adjusted to a position slightly inside the temperature rising region 40 .
  • the magnetization direction of the magnetic wire 2 is reversed at the portion 2 ⁇ where the magnetic wire 2 enters the temperature rising region 40 .
  • the portion 2 ⁇ where the magnetic wire 2 enters the temperature rising region 40 becomes the unit reversal magnetic domain length.
  • the unit reversal domain length can be made finer.
  • the material magnetically coupled to the magnetic wire is irradiated with the pulsed light for communication, and the material is heated by the irradiation, and the temperature rises.
  • An example in which a phenomenon in which the magnetization direction of the material is reversed is obtained by this, and the reversal phenomenon is propagated to the magnetic nanowire will be shown.
  • a photosensitive magnetic wire is formed by a combination of a material 242 whose magnetization direction in a region irradiated with a unit light pulse changes in the direction of the external magnetic field and a magnetic wire 2 magnetically coupled to the material 242. are doing.
  • 242 is a multi-layer film frequently used in magneto-optical memory materials, comprising a recording layer and a memory layer.
  • a reference numeral 242 ⁇ indicates a region where the material 242 and the magnetic wire 2 are magnetically coupled, and the magnetization direction of the magnetic wire 2 is aligned with the magnetization direction of the portion 242 ⁇ .
  • the magnetic wire 2 and the material 242 are insulated by an insulating film 243, but the insulating film 243 is thin and does not interfere with magnetic coupling.
  • the length of the unit reversal magnetic domain can be adjusted by the length of the region where the material 242 and the magnetic wire 2 are magnetically coupled, and can be easily adjusted to a desired length.
  • FIG. 25 shows an embodiment using another magnetic wire 252 that intersects the magnetic wire 2, and the added magnetic wire 252 is irradiated with pulsed light.
  • the magnetic wire 2 and the magnetic wire 252 are connected by a non-magnetic conductor 254 .
  • This non-magnetic wire 254 is obtained by implanting ions into a magnetic wire to lose the ability to move magnetic domains.
  • An insulating film 253 is interposed between the magnetic wire 2 and the magnetic wire 252 at the crossover point to prevent the formation of a short circuit.
  • the magnetic wire 252 is magnetized downward over its entire length.
  • the light pulse irradiates the illuminated area 10
  • its center is heated above the inversion temperature. Since the magnetic wires 252 around the temperature rising region are magnetized downward, a magnetic field leaking from the magnetic wires 252 around the temperature rising region is applied to the temperature rising region.
  • An upward magnetic field is generated at the center of the downward magnetic field.
  • an upward external magnetic field acts on the temperature rising region, and the magnetization direction thereof is reversed upward.
  • the downwardly magnetized magnetic wire 252 also serves as an external magnetic field generator, and the leakage magnetic field is used to reverse the magnetization direction of the temperature rising region.
  • the dark pulse is applied, no temperature rise region is formed and no reversal phenomenon occurs.
  • the magnetic wire 252 is formed with an array of magnetic domains whose magnetization directions are reversed corresponding to the light-dark change pattern of the pulsed light. .
  • the magnetization direction of the magnetic wire 252 is transferred to the magnetic wire 2 when passing through the flyover.
  • an array of magnetic domains whose magnetization directions are reversed corresponding to the light-dark change pattern of the pulsed light is formed in the magnetic wire 2, and the array moves from left to right.
  • the length of the unit reversed magnetic domain formed in the magnetic wire 2 can be adjusted by the shape of the crossover portion of the magnetic wire 252 and the magnetic wire 2, and can be easily adjusted to a desired length.
  • the magnetic wire 252 of this embodiment is of a photosensitive type, the magnetic wire 2 may not be of a photosensitive type.
  • the non-magnetic conductor 264 crosses over the magnetic wire 2 .
  • a current is applied to the non-magnetic wire 264 and the magnetic wire 2 to generate an external magnetic field for writing by the non-magnetic wire 264 and move the domain wall in the magnetic wire 2 .
  • the center of the pulsed light is on the right side of the flyover and heats well the magnetic wire 2 located on the right side.
  • the current flowing through the non-magnetic conductor 264 produces an upward external magnetic field.
  • the temperature rises in the area on the right side of the grade crossing and the magnetization direction is reversed upward.
  • the dark pulse is applied, the temperature does not rise, so the inversion does not occur.
  • the current for moving the domain wall in the magnetic wire 2 can be the current for obtaining the external magnetic field for writing.
  • a downward magnetic field is generated by the current on the left side of the flyover.
  • By arranging the magnetic path it is possible to obtain a relationship in which the downward magnetic field concentrates and passes through a specific portion of the magnetic wire 2 .
  • a downward magnetic field having a strength greater than the coercive force of the magnetic wire at room temperature can be applied to the magnetic wire 2, and this can be used as an external magnetic field for initial magnetization.
  • a photosensitive type is used for the magnetic wire 2 of this embodiment.
  • the tip of an optical fiber 272 can be displaced in the X and Y directions by an XY actuator 273.
  • FIG. By moving in the X direction, the magnetic wire to be used can be selected, and by moving in the Y direction, the irradiation position can be displaced in the length direction of the magnetic wire. This can extend the life of the storage device.
  • a condensing lens 274 is formed on the rear surface of a transparent substrate 271, and magnetic wires 2 and the like are formed on the surface of the transparent substrate.
  • FIG. 28 shows a process of forming a condensing lens 274 on the back surface of the transparent substrate 271 and forming the magnetic wire 2 and the like on the surface of the transparent substrate 271 .
  • the transparent substrate 271 is made of resin and can be molded using a mold.
  • the condensing lens 274 can be formed by forming a lens surface in a mold.
  • a mold is used to form a step in the magnetic wire forming region.
  • An RE-TM film is deposited on the step forming region.
  • the nanoimprint technology using a molding die it is possible to improve mass productivity of memory devices and reduce manufacturing costs. Since the RE-TM film deposited on the top surface and the RE-TM film deposited on the bottom surface of the step are separated in the vertical direction in FIG. you don't have to. The number of magnetic wires that can be formed per unit area can be increased.
  • the magnetic wire 2 may use an alloy or may use a multilayer film.
  • the vapor deposition process may be repeated on the stepped portion, and nanoimprinting can be used.
  • a plurality of magnetic wires A1, A2, A3, and A4 may be arranged along the optical axis of the condensed pulsed light for communication 9A.
  • Each magnetic wire is thin and transparent, and all of the magnetic wires A1, A2, A3, and A4 arranged along the optical axis can be heated above the inversion temperature by the communication pulse light 9A. can.
  • the magnetic wire for writing data can be selected by selecting the magnetic wire to which the current for moving the domain wall is applied from among the magnetic wires A1, A2, A3, and A4.
  • the reading light 29 is used to select and energize the magnetic wire whose magnetization direction is to be read. Then, a magneto-optical phenomenon occurs between the energized magnetic wire and the reading light 29, and by detecting it, the magnetization direction of the energized magnetic wire can be detected.
  • the magnetic wire 2 can be efficiently heated by the pulsed light 9 for communication. Both can be compatible.
  • the focal depth of the communication pulsed light 9 can be displaced in the optical axis direction.
  • the focal depth of the pulsed light for communication 9 can be adjusted in three stages. 9B is not shown but is at an intermediate depth between 9A and 9C.
  • four magnetic wires A1, A2, A3 and A4 are arranged for the condensed communication light 9A
  • four magnetic wires B1, B2, B1 and B2 are arranged for the condensed communication light 9B.
  • B3 and B4 are arranged, and four magnetic wires C1, C2, C3 and C4 are arranged for the condensed communication light 9C.
  • the focal depth is adjusted to that shown at 9C.
  • the condensed communication pulse light 9B is too deep for the four magnetic wires A1, A2, A3, and A4 to be heated to the reversal temperature, and the four magnetic wires A1, A2, A3, and A4
  • the condensed communication pulse light 9B is too shallow for the magnetic wires C1, C2, C3, and C4, so that they are not heated to the reversal temperature.
  • the four magnetic wires B1, B2, B3, and B4 are heated to the inversion temperature or higher by the communication pulsed light 9B.
  • the focal depth of the reading light 29 can also be displaced in the optical axis direction.
  • pulsed light with different wavelengths and polarization planes may pass through a single communication optical fiber.
  • the light can be split into pulsed lights of different types.
  • the apparatus of FIG. 29 can be applied to the pulsed light thus dispersed.
  • pulsed light with a wavelength of ⁇ 1 is collected as shown in 9A and stored in magnetic wires A1 to A4, and pulsed light with a wavelength of ⁇ 2 is collected as shown in 9B and stored in magnetic wires B1 to B4.
  • the pulsed light with a wavelength of ⁇ 3 can be condensed as shown in 9C and stored in the magnetic wires C1 to C4.
  • FIG. 30 shows an embodiment using a plasmon antenna to narrowly limit the irradiation area of the pulsed light 9 for communication.
  • the irradiation area of the pulsed light 9 for communication can be concentrated in a narrow area indicated by 30c, which enhances the effect of raising the temperature of the magnetic wire 2A and shortens the length of the reversed magnetic domain to store data. Density can be increased.
  • the plasmon antennas 30d and 30e are used, the irradiation area of the pulsed light 9 for communication can be concentrated in a narrow area indicated by 30f, which enhances the effect of increasing the temperature of the magnetic wire 2B and shortens the length of the reversed magnetic domain to store data.
  • plasmon antennas 31a, 31b, and 31c are used to concentrate the irradiation area of the pulsed light for communication 9 on a narrow area 31d on the magnetic wire 2A and a narrow area 31e on the magnetic wire 2B. can also
  • the magnetic wire 2 may be branched into branch lines 2a and 2b.
  • the array of magnetic domains formed in the magnetic wire 2 before branching is moved and stored in both the branched magnetic wires 2a and 2b, enabling data mirroring.
  • the number of branch lines is not limited, and may be three or more. Moreover, there is no restriction on the number of branch points, and the branch may be branched at a plurality of points.
  • the magnetic domain migration speed can be changed according to the position along the length of the continuous magnetic wire.
  • a current of 2I flows through the magnetic wire 2 before branching, and a current of I flows through each of the magnetic wires 2a and 2b after branching.
  • the magnetic domain migration speed is fast in the magnetic wire 2 before branching, and the magnetic domain migration speed is slow in the magnetic wires 2a and 2b after branching.
  • a phenomenon can be obtained in which the magnetic domain migration speed in the magnetic wire 2 before branching is 2500 m/sec, and the magnetic domain migration speed in the magnetic wires 2a and 2b after branching is 1250 m/sec (current and the magnetic domain migration side are not necessarily not proportional, but may be proportional).
  • the length of the magnetic domain 32A in the magnetic wire 2 before branching is 250 nm
  • the length of the magnetic domains 32B and 32C in the magnetic wires 2a and 2b after branching is 125 nm. can be done.
  • data stored in one photosensitive magnetic wire 330 can be transferred and stored by being distributed to a plurality of magnetic wires.
  • the information is transferred and stored in 16 magnetic wires indicated by 331 to 346 (however, reference numbers 333 to 344 are omitted).
  • a region 370 is irradiated with pulsed light, and a row of magnetic domains whose magnetization direction changes in accordance with the change pattern of light and dark of the pulsed light is stored.
  • An arrow 350 indicates the magnetic domain movement direction of the magnetic wire 330 .
  • the array of magnetic domains may be stored in the magnetic wire 330 through a material whose magnetization direction is reversed by a unit light pulse.
  • the 16 magnetic wires 331 to 346 cross over one magnetic wire 330 at intervals corresponding to the unit magnetic domain length of the magnetic wire 330 .
  • An arrow 351 indicates the magnetic domain movement direction of the magnetic wires 331-346.
  • a plurality of transfer magnetic wires 331 to 346 three-dimensionally cross a write magnetic wire 330 that changes the magnetization direction of the magnetic domain according to data at intervals corresponding to the unit magnetic domain length in the magnetic wire 330 . and are magnetically coupled at the flyover.
  • the first transfer magnetic wire 331 stores the 1st, 17th, 33rd, 49th, .
  • the fifteenth transfer magnetic wire 345 stores the 15th, 31st, 47th, 63rd, . . . , bit data is stored.
  • 360 in FIG. 33 denotes an M-RAM which will be described later.
  • FIG. 34 shows the process of dispersing and storing the data of the magnetic wire 330 to the three magnetic wires 331, 332, and 333.
  • (a) the case where unit bright pulses and unit dark pulses are alternately repeated will be described.
  • (c) to (g) schematically show the magnetic domains in the magnetic wire 330 and the transfer magnetic wires 331, 332, and 333.
  • Left-sloping hatches indicate reversed magnetic domains in the magnetic wire 330
  • right-sloping hatches indicate reversed magnetic domains.
  • hatching indicates reversed magnetic domains in the transferred magnetic wires 331, 332, and 333, and cross-hatching is given to the overlapping regions.
  • Time t4 indicates the end time of the unit dark pulse corresponding to the fourth bit, and the right end of each magnetic domain in the magnetic wire 330 coincides with the right ends of the transferred magnetic wires 331, 332, and 333.
  • FIG. Time t4a indicates the time when each magnetic domain in the magnetic wire 330 advances to the right from time t4 and the left end of each magnetic domain in the magnetic wire 330 coincides with the left ends of the transferred magnetic wires 331, 332, and 333.
  • the transfer magnetic wire 331 stores the first bit data
  • the transfer magnetic wire 332 stores the second bit data
  • the transfer magnetic wire 332 stores the third bit data
  • Time t7 indicates the end time of the unit bright pulse corresponding to the 7th bit, and the right end of each magnetic domain in the magnetic wire 330 coincides with the right ends of the transferred magnetic wires 331, 332, and 333. That is, the right end of the magnetic domain corresponding to the 4th bit coincides with the right end of the magnetic wire 331, the right end of the magnetic domain corresponding to the 5th bit coincides with the right end of the magnetic wire 332, and the right end of the magnetic domain corresponding to the 6th bit. coincides with the right end of the transferred magnetic wire 333 .
  • Time t7a indicates the time when each magnetic domain in the magnetic wire 330 advances to the right and the left end of each magnetic domain in the magnetic wire 330 coincides with the left ends of the transferred magnetic wires 331, 332, and 333.
  • the left end coincides with the left end of the transfer magnetic wire 333 .
  • the magnetization directions of the regions of the transfer magnetic wires 331, 332, and 333 magnetically coupled to the magnetic wire 330 do not change.
  • the magnetic domains having the magnetization directions move upward during the period. do.
  • the 4th bit data is newly stored in the transfer magnetic wire 331
  • the 5th bit data is newly stored in the transfer magnetic wire 332
  • the 6th bit data is newly stored in the transfer magnetic wire 332 .
  • the transfer magnetic wire 331 stores 1st, 4th, . . . bits of data
  • the transfer magnetic wire 332 stores 2nd, 5th, . 3rd, 6th, . . . bits of data are stored in the transfer magnetic wire 332 .
  • the data transmission speed in each of the transfer magnetic wires 331 , 332 , 333 is reduced to 1 ⁇ 3 of the data transmission speed in the magnetic wire 330 .
  • the electric field shown in (b) is applied to the magnetic wire for transfer every two or more pulses of the pulsed light for communication shown in (a). In the case of FIG.
  • the transfer magnetic wires 331, 332, and 333 an electric field is applied to the transfer magnetic wire every three pulses of the pulsed light for communication.
  • the magnetic domains intermittently move, and data can be read using the stop period.
  • the period available for reading data can be lengthened, and the time allocated for data reading processing can be lengthened.
  • a TMR sensor can be used for the sensor 12 shown in FIG. As shown in FIG. 35, the TMR sensor uses a sensor 386 to detect the series resistance of the magnetic domain 380 of the magnetic wire, the intermediate layer 382, and the fixed layer 384 whose magnetization direction is fixed downward. If the magnetization directions of the magnetic domain 380 and the pinned layer 384 match, the resistance becomes low, and if they do not match, the resistance becomes high. can be done.
  • the magnetic wire 380 may be adhered to an existing TMR sensor in which a free layer 390, an intermediate layer 382, a fixed layer 384, and a sensor 386 are laminated via an insulating layer 388.
  • FIG. The magnetization direction of the magnetic wire 380 is transferred to the free layer 390 .
  • the resistance value detected by the sensor 386 changes depending on the magnetic field direction of the magnetic domain 380 .
  • FIG. 37 replaces the sensor 386 of FIG. 35 with a transistor 392, resulting in an M-RAM.
  • 38 similar to FIG. 36, a magnetic wire 380 is adhered to an existing M-RAM with an insulating layer 388 interposed therebetween.
  • transistor 392 is turned on or off. For example, if the magnetization direction of the magnetic domain 380 is reversed, the transistor 392 is turned off, and if the magnetization direction of the magnetic domain 380 is not reversed, the transistor 392 is turned on.
  • the magnetization direction of the magnetic domain 380, the brightness and darkness of the pulse corresponding to the magnetic domain, and the data 1, 0 written in the magnetic wire can be determined from the ON or OFF of the transistor 392 .
  • the structures of FIGS. 37 and 38 are M-RAMs themselves, allowing random access to data for computation. That is, when transmitting to HDD17, the calculation using data is enabled.
  • FIG. 39 shows an embodiment in which 25 magnetic wires 392-1 to 392-25 are distributed and stored, and 1st, 26th, 51st, . , 2nd, 27th, 52nd, . Store data.
  • Each EO modulator utilizes the phenomenon that the refractive index of the clad of the optical fiber 391 changes depending on whether voltage is applied. With no voltage applied, the refractive index of the cladding is at its normal value, and communication light travels along the length of the optical fiber confined to the core. When a voltage is applied to the EO modulator, the refractive index of the clad increases, and communication light leaks out of the optical fiber from the core through the clad. The leaked communication light is condensed by a condensing lens and illuminates the corresponding photosensitive magnetic wire.
  • both the unit bright pulse time T and the unit dark pulse time T are 40 psec, and the communication speed is 25 Gbps.
  • the refractive index of the core is 1.5.
  • (1) of FIG. 39 shows the distribution of brightness of the communication light in the optical fiber 391 at time t1. Since the communication light speed in the communication optical fiber 391 has a relation of light speed in vacuum/refractive index of the core, the length L of the bright region and the length L of the dark region are 8 mm.
  • the 25 EO modulators EO1 to EO25 are arranged at intervals of 8 mm equal to the length L of the bright region and the length L of the dark region.
  • the arrow A indicates the direction in which the bright area and the dark area advance, the hatched area indicates the bright area, and the unhatched area indicates the dark area.
  • Numerals such as 1 and 2 indicate bit numbers.
  • Time t1 indicates the time when the tips of the bright region and the dark region (hereinafter collectively referred to as pulse regions) within the optical fiber 391 coincide with the right ends of the respective EO modulators. Assuming that the pulse region corresponding to the first EO modulator EO1 at this time is the first bit, the second bit corresponds to the second EO modulator EO2 and the twenty-fifth bit corresponds to the twenty-fifth EO modulator EO25. It is in. Time t1a shown in (2) of FIG. 39 indicates the time when the rear end of the pulse region coincides with the left end of each EO modulator.
  • the first bit continues to correspond to the first EO modulator EO1
  • the second bit continues to correspond to the second EO modulator EO2
  • the 25th bit continues to correspond to the 25th EO modulator EO25. It can be seen that the bits remain in corresponding positions. If a voltage is applied to the EO modulators EO1 to EO25 during times t1 to t1a, the first bit communication light irradiates the first magnetic wire 392-1, and the second bit communication light irradiates the second magnetic wire. 392-2, and the 25th bit of communication light illuminates the 25th magnetic wire 392-25.
  • the magnetic domains in the irradiated region of the magnetic wire are reversed, and if the communication light that irradiates the magnetic wire is dark, the magnetic domains in the irradiated region of the magnetic wire are not reversed. Hatched domains indicate reversed domains, and unhatched domains indicate non-reversed domains. Data transmitted by the communication light is written in the photosensitive magnetic wire.
  • Time t2 in (1) of FIG. 39 indicates the time when 40 psec ⁇ 25 pulse times have elapsed from time t1.
  • the 26th bit is at the corresponding position for the first modulator EO1
  • the 27th bit is at the corresponding position for the second EO modulator EO2
  • the 50th bit is at the 25th EO modulator EO25.
  • the bits are in corresponding positions.
  • the 26th bit data is stored in the first magnetic wire 392-1
  • the 27th bit data is stored in the second magnetic wire 392-2
  • the 50th bit of data is stored in the second magnetic wire 392-25.
  • each magnetic wire a reversed magnetic domain is formed when the data light is bright, and a non-reversed magnetic domain is formed when the data light is dark.
  • the domain length of the magnetic domain is approximately 1 ⁇ m.
  • a current is applied to each magnetic wire to move the magnetic domain in the arrow B direction. For this storage device, one storage operation is performed every 25 bits.
  • the cycle of memory processing is 1000 psec. In each magnetic wire, a current is passed through which the magnetic domain moves at a speed of 1 ⁇ m/1000 psec (1000 m/sec).
  • the width W of the magnetic wire is approximately 1 ⁇ m, while the spacing L between adjacent EO modulators is 8 mm. Therefore, as shown in FIG. 39(4), it is possible to arrange 4000 magnetic wires within the interval L between the adjacent EO modulators while securing the interval G of 1 ⁇ m between the adjacent magnetic wires. It is possible. If the magnetic wire group can move in the direction of arrow A relative to the EO modulator group, it becomes possible to select the magnetic wire for storing data from among 4000 magnetic wires. The storage capacity can be multiplied by 4000.
  • the above is an example, and is not limited to it.
  • the interval L between adjacent EO modulators is 2 mm, and the movement speed of the magnetic domain in the magnetic nanowire is adjusted to 6000 m/sec, both of which are adjustable.
  • a plurality of magnetic wires can be arranged at intervals L between adjacent EO modulators.
  • storage device 2 magnetic wire 4: non-magnetic wire 6: external magnetic field generator for initialization 8: external magnetic field generator for writing 9: pulsed light passed through optical fiber for communication 10: irradiation area 12: magnetization Direction detection device (sensor) array 14: switch 15: DC power supply 16: control device 17: hard disk device 18: substrate 19: insulating film 40: temperature rising region 242: magnetization direction reversal/propagation material 273: XY actuator

Abstract

The present invention provides a storage device that writes, with pulsed light for communication, data transmitted by the pulsed light for communication.　Through irradiation of bright unit pulses, the temperature is increased, the magnetization direction is changed to the direction of an external magnetic field, and when an electric field is applied, a pulsed light for communication is irradiated on a light-responsive type magnetic fine wire in which a magnetic wall moves, and the electric field is applied. The magnetization direction is changed by the pulsed light for communication itself, which enables writing at the speed of optical communications, and the amount of electric power required for writing is reduced. When necessary, a plurality of magnetic fine wires are used for different purposes in accordance with time series, and a feature of simultaneously reading a plurality of bits is used in combination. Thereby, reading can be implemented at the speed of optical communications.

Description

記憶装置と記憶媒体とその製造方法Storage device, storage medium, and manufacturing method thereof
　本明細書は、通信用パルス光で書込可能な記憶装置と記憶媒体を開示し、記憶媒体の製造方法を開示する。 This specification discloses a storage device and a storage medium writable by pulsed light for communication, and discloses a method for manufacturing the storage medium.
　本明細書における下記の用語は下記を意味する。
　通信用パルス光：データに対応して点滅または明暗が変化するパルス光をいう。１Ｇｂｐｓ以上の高速通信速度を持っており、明パルスの光強度がｍＷ以下の微弱なものであり得る。
　通信用光ファイバー：通信用パルス光が通過する光ファイバーをいい、インフラを構成する光ファイバーのみならず、家屋・車両あるいは装置・機器・システム等における光通信に利用する光ファイバーを総称する。
　通信用光ファイバーを通過したパルス光：通信用光ファイバーを、周波数が異なる複数種類の通信用パルス光や偏光面が異なる複数種類の通信用パルス光が重畳した光が通過していることがある。本明細書では、通信用光ファイバーを通過した重畳光を波長と偏光面等で分光した光を、通信用光ファイバーを通過したパルス光という。通信用光ファイバーを通過したパルス光は、通信用パルス光の一種である。ただし、近距離光通信システム等では光ファイバーを利用しないことがあり、通信用光ファイバーを通過しない通信用パルス光も存在する。
　磁性細線：電界を印加すると磁区が材料中で移動する（磁区を画定する一対の磁壁が移動するといってもよい）材料で形成されている細線をいう。印加された電界によって電流が流れる場合と、例えば絶縁体を介して電位差を加えるために、電界は印加されても電流が流れない場合がある。合金の単一膜で形成されているものと、複数種類の膜が積層されているものがある。
　光感応型磁性細線：電界が印加されると磁区が移動する前記の磁性細線のうち、通信用パルス光が含む単位明パルスに照射されると照射領域の磁化方向が外部磁界の方向に変化する磁性細線をいう。磁性細線自体が光感応型材料（単位明パルスの照射によって磁化方向が変化する現象が生じるものを光感応型という）で形成されていてもよいし、光感応型の材料とその材料に磁気結合している磁性細線の組み合わせで構成してもよい。後者の場合の磁性細線は、光感応型であってもよいし光感応型でなくてもよい。
　記憶装置：光感応型磁性細線と電界印加装置と書込装置を備えており、通信用パルス光が伝達するデータ（例えば、１，１，１・・・あるいは１，０，１・・・といったビットの時系列的変化のパターン）を磁性細線に書込むことができる記憶装置をいう。データを記憶しておくことが重要であり、データを書込む際にはデータを読取る必要がない場合もある。データ読取装置は必要時に追加できればよく、この記憶装置に不可欠でない。
　単位明パルス：通信用パルス光に含まれる最短持続時間の明パルスをいい、その持続時間を単位明パルス時間という。複数個の単位明パルスが連続する場合があることから、実際の明パルスの持続時間が単位明パルス時間の倍数となることがある。
　単位暗パルス：通信用パルス光に含まれる最短持続時間の暗パルスをいい、その持続時間を単位暗パルス時間という。単位暗パルス時間は、単位明パルス時間に等しい場合もあれば、異なる場合もある。複数個の単位暗パルスが連続する場合があることから、実際の暗パルスの持続時間が単位暗パルス時間の倍数となることがある。
　単位パルス：単位明パルスと単位暗パルスを総称する。 The following terms used herein have the following meanings.
Communication pulsed light: A pulsed light that blinks or changes brightness in response to data. It has a high-speed communication speed of 1 Gbps or more, and the light intensity of the bright pulse can be as weak as mW or less.
Optical fiber for communication: Refers to optical fiber through which pulsed light for communication passes, and collectively refers not only to optical fiber that constitutes infrastructure, but also to optical fiber that is used for optical communication in houses, vehicles, devices, equipment, systems, etc.
Pulsed light that has passed through a communication optical fiber: Light in which a plurality of types of communication pulsed light with different frequencies or a plurality of types of communication pulsed light with different polarization planes are superimposed may pass through a communication optical fiber. In this specification, the light obtained by splitting the superimposed light that has passed through the optical fiber for communication according to the wavelength and plane of polarization is referred to as the pulsed light that has passed through the optical fiber for communication. Pulsed light that has passed through an optical fiber for communication is a kind of pulsed light for communication. However, some short-distance optical communication systems do not use optical fibers, and some pulsed light for communication does not pass through optical fibers for communication.
Magnetic wire: A wire made of a material whose magnetic domain moves in the material when an electric field is applied (it can be said that a pair of domain walls defining the magnetic domain move). An applied electric field may cause a current to flow, or an applied electric field may cause no current to flow, for example to apply a potential difference across an insulator. Some are made of a single film of alloy, and some are made of laminated films of multiple types.
Photosensitive magnetic nanowire: Among the above-mentioned magnetic nanowires, magnetic domains move when an electric field is applied. When irradiated with a unit bright pulse included in the pulsed light for communication, the magnetization direction of the irradiated region changes in the direction of the external magnetic field. A magnetic wire. The magnetic wire itself may be formed of a photosensitive material (a phenomenon in which the magnetization direction changes when irradiated with a unit light pulse is called a photosensitive type), or the photosensitive material and the material are magnetically coupled. It may be composed of a combination of magnetic wires that are in contact with each other. The magnetic wire in the latter case may or may not be of the photosensitive type.
Storage device: Equipped with a photosensitive magnetic wire, an electric field applying device, and a writing device, data transmitted by pulsed light for communication (for example, 1, 1, 1 . . . or 1, 0, 1 . . . A memory device that can write a pattern of time-series changes of bits) into a magnetic nanowire. It is important to store the data, and it may not be necessary to read the data when the data is written. A data reader is not essential to this storage device, as it can be added as needed.
Unit light pulse: A light pulse with the shortest duration included in the pulsed light for communication, and its duration is called a unit light pulse time. Since there may be multiple unit light pulses in succession, the actual light pulse duration may be a multiple of the unit light pulse time.
Unit dark pulse: A dark pulse with the shortest duration included in pulsed light for communication, and its duration is called a unit dark pulse time. The unit dark pulse time may or may not be equal to the unit light pulse time. Since a plurality of unit dark pulses may be consecutive, the actual dark pulse duration may be a multiple of the unit dark pulse time.
Unit pulse: collectively refers to a unit light pulse and a unit dark pulse.
　磁性細線にデータを書込む技術が盛んに研究されている。通常は、電流によって生じる磁界を利用して磁性細線の全長中の一部の長さ範囲の磁化方向を反転させる手法を用い、反転させるか反転させないかを時系列に従って制御することによってデータを書込む。この技術によって、通信用パルス光が伝達するデータを磁性細線に書込もうとすると、通信用パルス光の明暗の変化パターンに従って磁界発生用電流の通電の有無を切換える必要があり、光電変換過程が必要とされ、書込処理に必要な電力量が大きなものとなる。通信用パルス光自体によって磁性細線にデータを書込むことはできない。 Technology for writing data to magnetic wires is being actively researched. Normally, data is written by using a magnetic field generated by an electric current to reverse the magnetization direction of a part of the length of the magnetic nanowire, and controlling whether or not to reverse the direction according to the time series. enter. When this technology is used to write data transmitted by pulsed light for communication into a magnetic wire, it is necessary to switch the presence or absence of the current for generating the magnetic field according to the pattern of changes in brightness of the pulsed light for communication. The amount of power required and required for the write process is large. Data cannot be written in the magnetic wire by the communication pulsed light itself.
　非特許文献１では、磁性細線の一部にレーザー光を照射することによって磁化方向を反転させる。この技術では、レーザー光が備えている磁気項を利用して電子のスピン方向を反転させるために、高強度レーザー光を極短時間だけ照射する必要があり、出力が１００ＫＷにも及ぶフェムト秒レーザーを利用する。フェムト秒レーザーの繰返し動作速度は遅く、データの書込速度は０．１ｂｐｓとなっている。この技術では、強度がｍＷ以下の通信用パルス光によって磁化方向を反転させることはできない。また１Ｇｂｐｓ以上の通信速度に対応することもできない。 In Non-Patent Document 1, the magnetization direction is reversed by irradiating a part of the magnetic wire with a laser beam. In this technology, a femtosecond laser with an output of 100 kW needs to be irradiated with a high-intensity laser beam for a very short time in order to use the magnetic term of the laser beam to reverse the electron spin direction. take advantage of The repetitive operation speed of the femtosecond laser is slow, and the data writing speed is 0.1 bps. In this technique, the magnetization direction cannot be reversed by communication pulsed light with an intensity of mW or less. Also, it cannot support communication speeds of 1 Gbps or more.
　上記の技術では、通信用パルス光によって磁性細線にデータを書込むことができない。そんな折に、発明者らの研究によって、磁性細線の種類・仕様等を選択すると、通信用パルス光が含む単位明パルスを磁性細線に照射したときに、照射領域の磁化方向が外部磁界の方向に変化する現象が得られることが判明した。すなわち、通信用パルス光が「明」のときにはその昇温効果によって照射領域の磁化方向が外部磁界の方向に変化するとともに「暗」のときには磁化方向を変化させない磁性細線が存在することが確認された。この明細書では、単位明パルス照射後の磁化方向が、照射前の磁化方向から変化する磁性細線を光感応型磁性細線という。
　本明細書では、通信用パルス光によって磁化方向を変化させる光感応型現象と、磁区を磁性細線の長さに沿って移動させる現象を組み合わせることによって、通信用パルス光によって、その通信用パルス光が伝達するデータを、時系列に従って、磁性細線中に書込む装置を開示する。また記憶媒体とその製造方法を開示する。 With the above technology, data cannot be written to the magnetic wire using pulsed light for communication. In such a case, according to the inventors' research, if the type and specifications of the magnetic nanowire are selected, when the magnetic nanowire is irradiated with a unit bright pulse contained in the pulsed light for communication, the magnetization direction of the irradiated area will be the direction of the external magnetic field. It was found that a phenomenon of changing to That is, it was confirmed that when the pulsed light for communication is "bright", the magnetization direction of the irradiated area changes in the direction of the external magnetic field due to the temperature rise effect, and when it is "dark", there is a magnetic wire that does not change the magnetization direction. rice field. In this specification, a magnetic wire whose magnetization direction after irradiation with a unit light pulse changes from the magnetization direction before irradiation is referred to as a photosensitive magnetic wire.
In this specification, by combining a photosensitive phenomenon in which the magnetization direction is changed by the pulsed light for communication and a phenomenon in which the magnetic domain is moved along the length of the magnetic nanowire, the pulsed light for communication can Disclosed is an apparatus for writing data transmitted by a into a magnetic wire in chronological order. Also disclosed is a storage medium and method of manufacturing the same.
　レーザー光を磁性細線に照射する条件によっては、磁性細線が局所的に加熱され、磁性細線膜の膜面に沿った方向および／または垂直方向に大きな温度勾配が瞬間的に生じ、この温度勾配に沿って大量の熱電子流が生じる。この熱電子流はスピンを持っており、熱スピン流となる。この熱スピン流が作るSTT（スピン移行トルク）やSOT（スピン軌道トルク）により、磁化方向を外部磁界の方向に変化させる現象が容易化される。上記の熱スピン流を利用すると、磁化方向を変化させるのに要する単位明パルスの強度を低下することが可能となる。熱スピン流を有効に活用するためには、磁性層と重金属層の材料の組み合わせや厚みの選定が重要となる。本技術には、温度勾配に沿って流れる熱スピン流を利用して微弱な単位明パルスによって磁化方向を変化させる技術を適用することができる。 Depending on the conditions under which the magnetic nanowire is irradiated with laser light, the magnetic nanowire is locally heated, and a large temperature gradient is momentarily generated along and/or perpendicular to the film surface of the magnetic nanowire film. A large amount of thermionic current is generated along the This thermoelectron current has a spin and becomes a thermal spin current. STT (spin transfer torque) and SOT (spin orbit torque) produced by this thermal spin current facilitate the phenomenon of changing the magnetization direction to the direction of the external magnetic field. By using the thermal spin current, it is possible to reduce the intensity of the unit light pulse required to change the magnetization direction. In order to effectively utilize the thermal spin current, it is important to select the combination of materials and the thickness of the magnetic layer and the heavy metal layer. A technology that changes the magnetization direction by a weak unit light pulse using a thermal spin current that flows along a temperature gradient can be applied to this technology.
　本明細書で開示する記憶装置は、光感応型磁性細線と電界印加装置と書込装置を備えている。
　光感応型磁性細線は、通信用光パルス光が含む単位明パルスに照射されると照射領域の磁化方向が外部磁界の方向に変化するとともに電界が印加されると磁区が長さ方向に移動する性質を備えている。ここでいう磁区の移動とは、磁性細線自体は静止しており、その静止している磁性細線内において磁区が移動することをいう。
　電界印加装置は、磁性細線に電界を印加する。電界を印加することによって磁性細線に電流が流れる場合もあるが、例えば絶縁体を介して電位差を加えるために、電界は印加されても電流が流れないことがある。磁区移動速度は、電界強度または電流密度によって調整可能である。 The storage device disclosed in this specification includes a photosensitive magnetic wire, an electric field applying device, and a writing device.
When a photosensitive magnetic wire is irradiated with a unit light pulse included in optical pulse light for communication, the magnetization direction of the irradiated region changes in the direction of the external magnetic field, and when an electric field is applied, the magnetic domain moves in the length direction. have the nature The movement of the magnetic domain here means that the magnetic wire itself is stationary and the magnetic domain moves within the stationary magnetic wire.
The electric field applying device applies an electric field to the magnetic wire. In some cases, the application of an electric field causes a current to flow through the magnetic wire, but in some cases, the electric field is applied but the current does not flow, for example, because a potential difference is applied through an insulator. The domain migration speed can be adjusted by electric field strength or current density.
　書込装置は、通信用パルス光が含む単位明パルスと外部磁界を利用して、光感応型磁性細線の照射領域の磁化方向を外部磁界の方向に変化させる。すなわち、通信用パルス光が明のときは、その明のパルス光に照射されることによって昇温し、照射領域の磁化方向を外部磁界の方向に変化させる。前記した熱スピン流を利用して磁化方向を変化させる場合もある。その一方において、通信用パルス光が暗（パルス光の強度がゼロまたは微弱）のときは、磁化方向を変化させる温度にまで昇温させない。 The writing device changes the magnetization direction of the irradiated area of the photosensitive magnetic wire to the direction of the external magnetic field by using the unit light pulse included in the pulsed light for communication and the external magnetic field. That is, when the pulsed light for communication is bright, the temperature is raised by being irradiated with the bright pulsed light, and the magnetization direction of the irradiated region is changed to the direction of the external magnetic field. In some cases, the magnetization direction is changed using the above-described thermal spin current. On the other hand, when the pulsed light for communication is dark (the intensity of the pulsed light is zero or weak), the temperature is not raised to a temperature that changes the magnetization direction.
　磁性細線の磁化方向を変化させるために、光感応型磁性細線にパルス光を直接に照射する技術を利用してもよいし、磁性細線に磁気結合している材料にパルス光を照射する技術を利用してもよい。その材料に、単位明パルスの照射によって昇温して外部磁界の方向に変化させる現象が生じれば、その磁化方向の変化現象を磁性細線に伝搬して磁性細線の一部の長さの磁化方向を外部磁界の方向に反転させることができる。 In order to change the magnetization direction of the magnetic nanowire, a technique of directly irradiating the photosensitive magnetic nanowire with pulsed light may be used, or a technique of irradiating a material magnetically coupled to the magnetic nanowire with pulsed light may be used. may be used. If the material is heated by irradiation with a unit light pulse and a phenomenon occurs in which it changes in the direction of the external magnetic field, the phenomenon of changing the magnetization direction is propagated to the magnetic wire and the magnetization of a part of the length of the magnetic wire is generated. The direction can be reversed in the direction of the external magnetic field.
　この技術では、外部磁界の方向に変化させる前の磁化方向を、外部磁界と異なる方向に向けておく必要がある。そのための構成は特に限定されず、磁性細線の全長に亘って前記の異なる方向に着磁させておいてもよいし、書込装置を通過するに先立って初期磁化装置を通過するようにし、その初期磁化装置で前記の異なる方向に着磁させてもよい。本明細書では磁化方向を外部磁界と異なる方向から外部磁界の方向に変化させることを、外部磁界の方向に反転させるということがある。 With this technology, the magnetization direction must be oriented in a direction different from that of the external magnetic field before it is changed to the direction of the external magnetic field. The configuration for this purpose is not particularly limited, and the entire length of the magnetic nanowire may be magnetized in the different directions described above, or the magnetic nanowire may be passed through an initial magnetization device prior to passing through the writing device, The initial magnetization device may be magnetized in the different directions described above. In this specification, changing the magnetization direction from the direction different from the external magnetic field to the direction of the external magnetic field is sometimes referred to as reversing the direction of the external magnetic field.
　本明細書で開示する記憶装置では、「磁区移動速度」＞「単位反転磁区長／（単位明パルス時間＋単位暗パルス時間）」の関係に設定しておく。ここでいう磁区移動速度とは、単位明パルス時間と単位暗パルス時間を通算した合計時間について算出した磁区の平均移動速度を意味する。単位明パルス時間内に磁区移動速度が変化する場合（例えば磁性細線に間欠的に電界を印加すると磁区は間欠的に移動する）、あるいは単位暗パルス時間内に磁区移動速度が変化する場合は、前記合計時間内の平均移動速度をいう。この速度条件が満たされていると、単位となる最小非反転磁区を挟んで隣接する２個の反転磁区の間に非反転磁区が残存し、非反転磁区が消失することがない。 In the storage device disclosed in this specification, the relationship is set to "magnetic domain movement speed" > "unit reversal magnetic domain length/(unit bright pulse time + unit dark pulse time)". The term "magnetic domain movement velocity" as used herein means the average movement velocity of the magnetic domains calculated for the total time obtained by integrating the unit bright pulse time and the unit dark pulse time. When the magnetic domain migration speed changes within the unit light pulse time (for example, when an electric field is intermittently applied to the magnetic wire, the magnetic domain moves intermittently), or when the magnetic domain migration speed changes within the unit dark pulse time, It refers to the average speed of movement within the total time. When this speed condition is satisfied, a non-reversed magnetic domain remains between two adjacent reversed magnetic domains across a unit minimum non-reversed magnetic domain, and the non-reversed magnetic domain does not disappear.
　ここでいう単位反転磁区長とは、単位明パルスの照射によって磁化方向が反転する領域の磁性細線の長さに沿った距離をいう。後記する単位非反転磁区長と相違することがあるし、単位磁区長とも相違することがある。本明細書でいう長さは、特に断らない限り、磁性細線の長さに沿った距離をいう。 The unit reversal magnetic domain length here refers to the distance along the length of the magnetic wire in the region where the magnetization direction is reversed by the irradiation of the unit light pulse. It may differ from the unit non-inverted magnetic domain length, which will be described later, and may also differ from the unit magnetic domain length. As used herein, length refers to the distance along the length of the magnetic wire unless otherwise specified.
　必要ならこの記憶装置に読取装置を付加することができる。後記のように読取装置には電気信号処理が必要とされ、通信用パルス光の通信速度が高速の場合には、明暗の変化周期内に読取処理を完了することが難しい。この記憶装置の場合、後記するように、複数本の磁性細線と複数個の磁化方向検出装置を同時に利用して実質的な読取速度を高速化することができ、通信用パルス光の通信速度と、書込速度と、実質的な読取速度を一致させることができる。例えばハードディスクといった外部装置に、通信用パルス光が伝達したデータを中継・伝送・転送することができる。 If necessary, a reading device can be added to this storage device. As will be described later, the reader requires electrical signal processing, and when the communication speed of the pulsed light for communication is high, it is difficult to complete the reading process within the light-dark change period. In the case of this storage device, as will be described later, a plurality of magnetic wires and a plurality of magnetization direction detectors can be used simultaneously to substantially increase the reading speed. , the writing speed and the actual reading speed can be matched. For example, data transmitted by the communication pulse light can be relayed, transmitted, and transferred to an external device such as a hard disk.
　１本の磁性細線に書込んだ磁区の並びを、複数本の転写磁性細線に分散して転写することも可能である。例えば、３本の転写磁性細線を利用し、第１転写磁性細線に第１，４，７・・・ビットを記憶し、第２転写磁性細線に第２，５，８・・・ビットを記憶し、第３転写磁性細線に第３，６，９・・・ビットを記憶することもできる。このようにしても、データの読取に利用可能な時間を長時間化することができる。 It is also possible to distribute and transfer the alignment of the magnetic domains written in one magnetic wire to a plurality of transfer magnetic wires. For example, using three transfer magnetic wires, the first transfer magnetic wire stores the 1st, 4th, 7th, . . . bits, and the second transfer magnetic wire stores the 2nd, 5th, 8th, . However, the 3rd, 6th, 9th, . . . bits can also be stored in the third transfer magnetic wire. Also in this way, the time available for reading data can be lengthened.
　本明細書で開示する技術は、様々な記憶媒体を新たに提供する。例えば、単位明パルスによる昇温に関連して集光レンズ・断熱性・ヒートシンク等に特徴を持つ記憶媒体を提供し、データを二重ないし分散して記憶するために複数本の磁性細線を備えている記憶媒体を提供し、複数本の磁性細線を実現する新たな構造を提供する。また磁化方向検出装置と磁化方向に依存してオン・オフするトランジスタ等によってＭ－ＲＡＭ構造を実現する記憶媒体を提供する。さらに、記憶媒体の製造方法も提供する。 The technology disclosed in this specification newly provides various storage media. For example, we will provide a storage medium with features such as a condenser lens, heat insulation, heat sink, etc. in relation to the temperature rise by a unit light pulse, and provide a plurality of magnetic wires to store data in duplicate or in a distributed manner. The present invention provides a storage medium that holds multiple magnetic wires, and provides a new structure that realizes a plurality of magnetic wires. Also provided is a storage medium that realizes an M-RAM structure by means of a magnetization direction detection device and a transistor or the like that is turned on/off depending on the magnetization direction. Furthermore, a method of manufacturing a storage medium is also provided.
　本明細書で開示する記憶装置では、通信用パルス光（正確には単位明パルス）による昇温によって直接ないし間接に磁性細線の一部の長さの磁化方向を反転させる現象と、その磁区を磁性細線の長さに沿って移動させる現象を組み合わせて用い、磁性細線中に明パルスに対応する反転磁区と暗パルスに対応する非反転磁区の並びを形成し、通信用パルス光が伝達したデータを磁性細線中に記憶することができる。
　通信用パルス光自体で直接ないし間接に磁性細線にデータを書込むために、光を利用する高速度通信に対応することができる。また光電変換過程を必要としないために記憶装置の運転に必要な電力量が低減される。 In the storage device disclosed in the present specification, the phenomenon of directly or indirectly reversing the magnetization direction of a part of the length of the magnetic wire due to the temperature rise by the pulsed light for communication (more precisely, the unit light pulse), and the magnetic domain Using a combination of phenomena that move along the length of the magnetic nanowire, we form an array of reversed magnetic domains corresponding to the bright pulse and non-reversed magnetic domains corresponding to the dark pulse in the magnetic nanowire, and data transmitted by the pulsed light for communication. can be stored in the magnetic wire.
Since data is directly or indirectly written in the magnetic wire by the pulsed light for communication itself, it is possible to cope with high-speed communication using light. Also, since no photoelectric conversion process is required, the amount of power required to operate the storage device is reduced.
実施例の記憶装置の模式的平面図。FIG. 2 is a schematic plan view of the storage device of the embodiment; 図１の記憶装置の模式的断面図。FIG. 2 is a schematic cross-sectional view of the storage device in FIG. 1; 図１の記憶装置の動作を説明するタイミングチャート。2 is a timing chart for explaining the operation of the storage device in FIG. 1; 昇温領域と外部磁界有効領域と反転磁区の関係を説明する図。FIG. 4 is a diagram for explaining the relationship between a temperature rise region, an external magnetic field effective region, and a reversed magnetic domain; パルス光と磁性細線中の磁区の関係を説明する図。FIG. 4 is a diagram for explaining the relationship between pulsed light and magnetic domains in a magnetic nanowire; 外部磁界発生装置の別例を説明する図。The figure explaining another example of an external magnetic field generator. 外部磁界発生装置の他の別例を説明する図。FIG. 10 is a diagram for explaining another example of the external magnetic field generator; 実施例の記憶媒体の模式的断面図。FIG. 2 is a schematic cross-sectional view of the storage medium of the example; 磁性細線と昇温領域と反転磁区を説明する図。FIG. 4 is a diagram for explaining a magnetic wire, a temperature rising region, and a reversed magnetic domain; ヒートシンクが存在する場合の昇温領域と反転磁区を説明する図。FIG. 4 is a diagram for explaining a temperature rise region and reversed magnetic domains when a heat sink is present; ヒートシンクが存在する場合の昇温領域と反転磁区の別例を説明する図。FIG. 10 is a diagram for explaining another example of a temperature rising region and reversed magnetic domains when a heat sink is present; 実施例の記憶装置の動作を説明する図。4A and 4B are diagrams for explaining the operation of the storage device of the embodiment; FIG. 書込時のパワーと読取信号の電圧の関係を示す。2 shows the relationship between the power in writing and the voltage of the read signal. 磁性細線の通電密度と磁区移動速度の関係を示す。2 shows the relationship between the current density of a magnetic nanowire and the magnetic domain migration speed. 受信感度と転送速度（転送レート）の関係を示す。The relationship between reception sensitivity and transfer speed (transfer rate) is shown. 転送速度（転送レート）とデータ転送に要する消費電力の関係を示す。The relationship between transfer speed (transfer rate) and power consumption required for data transfer is shown. ４本の光ファイバーを利用する記憶装置の模式的斜視図。1 is a schematic perspective view of a storage device using four optical fibers; FIG. 図１７の記憶装置の表面図。FIG. 18 is a surface view of the storage device of FIG. 17; 図１７の記憶装置の照射領域と外部磁界有効領域と磁性細線の関係を示す。FIG. 17 shows the relationship between the irradiation area, the external magnetic field effective area, and the magnetic wire in the storage device of FIG. ４本の光ファイバーを利用する別例の記憶装置の斜視図。FIG. 4 is a perspective view of another example of a storage device that utilizes four optical fibers; 図２０の記憶装置の裏面図。FIG. 21 is a rear view of the storage device of FIG. 20; 図２０の記憶装置の表面図。FIG. 21 is a surface view of the storage device of FIG. 20; 図２０の記憶装置の照射領域と外部磁界有効領域と磁性細線の関係を示す。FIG. 20 shows the relationship between the irradiation area, the external magnetic field effective area, and the magnetic wire in the storage device of FIG. 別例１の記憶装置の断面図と平面図。4A and 4B are a cross-sectional view and a plan view of a storage device of Example 1; 別例２の記憶装置の断面図と平面図。11A and 11B are a cross-sectional view and a plan view of a storage device of Example 2; 別例３の記憶装置の断面図と平面図。13A and 13B are a cross-sectional view and a plan view of a storage device of Example 3; 別例４の記憶装置の斜視図。FIG. 11 is a perspective view of a storage device of Example 4; 別例５の記憶装置の断面図。FIG. 11 is a cross-sectional view of a storage device of Example 5; 別例６の記憶装置の斜視図。FIG. 11 is a perspective view of a storage device of Example 6; 別例７の記憶装置の平面図。FIG. 11 is a plan view of a storage device of another example 7; 別例８の記憶装置の平面図。FIG. 11 is a plan view of a storage device of Example 8; 別例９の記憶装置の平面図。FIG. 11 is a plan view of a storage device of Example 9; 別例１０の記憶装置の平面図。FIG. 11 is a plan view of a storage device of another example 10; 別例１０の記憶装置の動作説明図。FIG. 11 is an operation explanatory diagram of the storage device of another example 10; 別例１１の記憶装置の断面図。FIG. 11 is a cross-sectional view of a storage device of Example 11; 別例１２の記憶装置の断面図。FIG. 12 is a cross-sectional view of a storage device of Example 12; 別例１３の記憶装置の断面図。FIG. 21 is a cross-sectional view of a storage device of Example 13; 別例１４の記憶装置の断面図。FIG. 21 is a cross-sectional view of a storage device of another example 14; 別例１５の記憶装置の模式的斜視図。FIG. 21 is a schematic perspective view of a storage device of another example 15;
（第１実施例）
　図１は、実施例の記憶装置１の平面図を示し、光感応型磁性細線と電界印加装置と書込装置と読取装置（再生装置）と切換装置を備えている。本実施例では、磁性細線自体が光感応型である２本の光感応型磁性細線２Ａ，２Ｂを交互に利用する。以下では、光感応型磁性細線２Ａ，２Ｂを磁性細線２Ａ，２Ｂと略称する。電界印加装置は、２個の直流電源装置１５Ａ，１５Ｂと、２個のスイッチ１４Ａ，１４Ｂと、２本の非磁性導線４Ａ，４Ｂと、共通する非磁性導線４を備えている。書込装置は、初期磁化用の外部磁界発生装置６と、書込用の外部磁界発生装置８を備えており、通信用光ファイバーを通過したパルス光の照射範囲１０を利用する。読取装置は、磁性細線２Ａに書込まれた複数ビットのデータを同時に読取るセンサ列１２Ａと、磁性細線２Ｂに書込まれた複数ビットのデータを同時に読取るセンサ列１２Ｂとを備えている。本実施例では、磁性細線の磁化方向に依って抵抗値が変化するＴＭＲセンサを配列している。実施例の記憶装置は、その他に、制御装置１６を備えており、通信用パルス光が伝達したデータを、ハードディスク装置ＨＤＤ１７に転送ないし中継する。制御装置１６は、通信用パルス光に含まれるクロック信号に基づいて、電源装置１５Ａ，１５Ｂとスイッチ１４Ａ，１４Ｂの動作を制御し、センサ列１２Ａ，１２Ｂで検出されたデータをＨＤＤ１７に伝送する。磁性細線２Ａ，２Ｂは、電界印加装置と書込装置と読取装置の夫々の一部でもある。また、制御装置１６とスイッチ１４Ａ，１４Ｂ等が切換装置を構成している。 (First embodiment)
FIG. 1 shows a plan view of a storage device 1 of an embodiment, comprising a photosensitive magnetic wire, an electric field applying device, a writing device, a reading device (reproducing device), and a switching device. In this embodiment, two photosensitive magnetic wires 2A and 2B, whose magnetic wires themselves are photosensitive, are alternately used. Hereinafter, the photosensitive magnetic wires 2A and 2B are abbreviated as magnetic wires 2A and 2B. The electric field application device includes two DC power supply units 15A and 15B, two switches 14A and 14B, two non-magnetic conducting wires 4A and 4B, and a common non-magnetic conducting wire 4. FIG. The writing device includes an external magnetic field generator 6 for initial magnetization and an external magnetic field generator 8 for writing, and utilizes an irradiation range 10 of pulsed light that has passed through a communication optical fiber. The reading device includes a sensor array 12A for simultaneously reading multiple-bit data written on the magnetic wire 2A and a sensor array 12B for simultaneously reading multiple-bit data written on the magnetic wire 2B. In this embodiment, TMR sensors whose resistance value changes depending on the magnetization direction of the magnetic wire are arranged. The storage device of the embodiment also includes a control device 16, which transfers or relays data transmitted by the pulsed light for communication to a hard disk device HDD17. The control device 16 controls the operation of the power supply devices 15A and 15B and the switches 14A and 14B based on the clock signal contained in the communication pulse light, and transmits the data detected by the sensor arrays 12A and 12B to the HDD 17 . The magnetic wires 2A and 2B are also part of the electric field applying device, the writing device and the reading device, respectively. Also, the control device 16 and the switches 14A, 14B and the like constitute a switching device.
　図２は、断面図を示し、上記部材は、ポリカーボネイト基板１８上に形成されている。センサ列１２Ａ，１２Ｂの各々には、１６個のＴＭＲセンサが配置されており、各センサが制御装置１６に接続されているが、図２では一部の接続関係の図示を省略している。図２において、参照番号１９は誘電体であり、基板１８上に、センサ列１２Ａ，１２Ｂ、磁性細線２Ａ，２Ｂ、外部磁界発生膜６，８等を固定し、相互に絶縁している。
　なお本出願に用いる図面はあくまで技術説明のためのものあり、詳細の図示が省略されており、寸法等が正確に図示されていないことがある。 FIG. 2 shows a cross-sectional view in which the above members are formed on a polycarbonate substrate 18. As shown in FIG. 16 TMR sensors are arranged in each of the sensor rows 12A and 12B, and each sensor is connected to the control device 16, but the illustration of a part of the connection relationship is omitted in FIG. In FIG. 2, reference numeral 19 is a dielectric, and sensor arrays 12A and 12B, magnetic wires 2A and 2B, external magnetic field generating films 6 and 8, etc. are fixed on a substrate 18 and insulated from each other.
It should be noted that the drawings used in this application are for technical explanation only, and detailed illustration is omitted, and dimensions and the like may not be illustrated accurately.
　スイッチ１４Ａがオンすると直流電源装置１５Ａから電流が流れ、その電流は磁性細線２Ａを左から右に流れる。磁性細線２Ａは、ＲＥ－ＴＭフェリ磁性材で形成するのが好ましく、本実施例ではＴｂＣｏＦｅ合金を使用した。これに限定されるものでなく、希土類元素と３ｄ遷移元素を母体とする合金でもよいし、希土類元素と３ｄ遷移金属元素からなる多層膜でもよい。これらはフェリ磁性体であり、磁化容易軸が膜面に垂直な垂直磁化膜である。垂直磁化膜となる３ｄ遷移金属と貴金属からなる多層膜でもよい。これらの磁性細線は、電界を印可すると磁区が移動するだけでなく、通信用パルス光が含む単位明パルスに照射されると照射領域の磁化方向が外部磁界の方向に変化して固定される現象が生じる。磁性細線２Ａは、光感応型の材料で形成されており、それ自体が光感応型磁性細線である。 When the switch 14A is turned on, current flows from the DC power supply 15A, and the current flows through the magnetic wire 2A from left to right. The magnetic wire 2A is preferably made of an RE-TM ferrimagnetic material, and in this example, a TbCoFe alloy was used. The material is not limited to this, and may be an alloy based on a rare earth element and a 3d transition element, or may be a multilayer film composed of a rare earth element and a 3d transition metal element. These are ferrimagnetic materials, and are perpendicular magnetization films whose magnetization easy axis is perpendicular to the film surface. A multi-layered film composed of a 3d transition metal and a noble metal, which serves as a perpendicular magnetization film, may also be used. These magnetic wires not only move their magnetic domains when an electric field is applied, but also a phenomenon in which the magnetization direction of the irradiated region changes and is fixed in the direction of the external magnetic field when irradiated with a unit light pulse included in the pulsed light for communication. occurs. The magnetic wire 2A is made of a photosensitive material and is itself a photosensitive magnetic wire.
　電流で磁壁が移動するためにはスピン移行トルク（STT）が必要であり、磁性層と重金属層のヘテロ構造により大きなスピン軌道トルク（SOT）を有するものが良い。STTは磁性体内を流れる電子のスピンが磁壁を駆動する力であるのに対し、SOTは重金属層を流れる電子の流れが、ヘテロ界面の影響で磁性層側に侵入することで磁壁を駆動する。一方、レーザー光を磁性細線に照射すると局所的に加熱され、膜面面内方向および垂直方向に大きな温度勾配が瞬間的に生じ、この温度勾配に沿って大量の熱電子流が生じる。この熱電子はスピンを持っている熱スピン流となる。この熱スピン流が作るSTTやSOTにより記録磁区が容易に形成できる。小さなレーザーパワーでも記録磁区が形成できる。この熱スピン流を有効に活用するためには、磁性層と重金属層の材料の組み合わせや厚みの選定が重要となる。 A spin transfer torque (STT) is necessary for the domain wall to move with current, and it is preferable to have a large spin-orbit torque (SOT) due to the heterostructure of the magnetic layer and the heavy metal layer. In STT, the spin of electrons flowing in the magnetic material drives the domain wall, whereas in SOT, the flow of electrons flowing in the heavy metal layer penetrates the magnetic layer due to the heterointerface and drives the domain wall. On the other hand, when a magnetic nanowire is irradiated with a laser beam, it is locally heated, and a large temperature gradient is instantaneously generated in the in-plane and vertical directions of the film, and a large amount of thermionic electrons flow along this temperature gradient. This thermal electron becomes a thermal spin current with spin. Recording magnetic domains can be easily formed by STT and SOT generated by this thermal spin current. Recording magnetic domains can be formed even with a small laser power. In order to effectively utilize this thermal spin current, it is important to select the combination of materials and the thickness of the magnetic layer and the heavy metal layer.
　光による昇温効果を高めるためには、磁性細線の光入射側と光透過側に、最適な誘電体層や光反射膜を配置して光を閉じ込める効果を増大する方法が良い。そのために磁性細線が光を透過させるほど薄いものが良い。光の閉じ込め効果を最大化するためには、反射光が光入射側に戻らない、あるいは透過光が出てこない構成が良い。 In order to enhance the effect of raising the temperature by light, it is better to increase the effect of confining light by arranging an optimal dielectric layer or light reflecting film on the light incident side and the light transmitting side of the magnetic nanowire. Therefore, it is preferable that the magnetic wire is thin enough to transmit light. In order to maximize the light confinement effect, it is preferable to have a configuration in which reflected light does not return to the light incident side or transmitted light does not come out.
　昇温効果を高めるためには、光を閉じ込めるだけでなく、磁性細線が断熱的だと良い。基板も含めて断熱構造とするのが有利である。例えば、基板には熱伝導率が小さなガラスやプラスチックが良い。Si基板の場合にも基板表面には100nm以上の誘電体膜があることが好ましい。 In order to increase the heating effect, it is better if the magnetic nanowires are adiabatic, in addition to confining the light. It is advantageous to have an adiabatic structure including the substrate. For example, glass or plastic with low thermal conductivity is good for the substrate. Also in the case of a Si substrate, it is preferable to have a dielectric film of 100 nm or more on the substrate surface.
　磁性細線２Ａに電界が印加されて電流が流れると、磁性細線２Ａ中の磁区と磁壁が電流と同方向に移動する。磁区と磁壁の移動速度は、電流値によって調整することができ、本実施例では、２５００ｍ／ｓｅｃの速度で移動する電流値を通電する。
　磁性細線２Ｂでも同様であり、重複記載は省略する。
　本明細書では、複数本の磁性細線を区別するために、添え字にアルファベットの大文字を用いる。複数本の磁性細線に共通する事象を説明する場合には、添え字を省略する。 When an electric field is applied to the magnetic wire 2A and current flows, the magnetic domains and domain walls in the magnetic wire 2A move in the same direction as the current. The movement speed of the magnetic domain and the domain wall can be adjusted by the current value, and in this embodiment, a current value that moves at a speed of 2500 m/sec is applied.
The same applies to the magnetic wire 2B, and redundant description is omitted.
In this specification, capital letters are used for subscripts in order to distinguish between a plurality of magnetic wires. Subscripts are omitted when describing phenomena common to a plurality of magnetic wires.
　初期磁化用の外部磁界発生装置（実施例では磁界発生膜）６は、常温における磁性細線２の保磁力より大きい強度の下向き磁界を磁性細線２に加える。外部磁界発生装置６は磁性細線２の左端に磁気結合しており、磁気結合領域を左から右に移動する磁区の磁化方向を下向きに揃える。 An external magnetic field generator (magnetic field generating film in the embodiment) 6 for initial magnetization applies a downward magnetic field having a strength greater than the coercive force of the magnetic wire 2 at room temperature to the magnetic wire 2 . The external magnetic field generator 6 is magnetically coupled to the left end of the magnetic wire 2, and aligns the magnetization directions of the magnetic domains moving from left to right in the magnetic coupling region downward.
　書込用の外部磁界発生装置（実施例では磁界発生膜）８は、常温での磁性細線２の保磁力よりは小さいが、昇温した磁性細線２の保磁力よりは大きい強度の上向きの磁界を磁性細線２に加える。外部磁界発生装置８は、外部磁界発生装置６よりも磁壁の移動方向の下流に配置されており、外部磁界発生装置６によって磁化方向が下向きに揃えられた磁区が外部磁界発生装置８と磁気結合する。外部磁界発生装置８は、通信用パルス光の照射領域１０の内側に配置されており、通信用パルス光の単位明パルスの照射によって昇温された領域が外部磁界発生装置８と磁気結合する。磁区が外部磁界発生装置８と磁気結合している領域を通過する際に、明パルスによって昇温されていれば、その通過磁区の磁化方向が上向きに反転し、暗パルスによって昇温されていなければ、その通過磁区の磁化方向は反転せず、下向きに維持される。これによって、明パルス照射中に外部磁界発生装置８との磁気結合領域を通過した磁区の磁化方向が上向きとなり、暗パルス照射中に磁気結合領域を通過した磁区の磁化方向が下向きとなり、磁性細線２の長さに沿って、明暗の時系列的変化パターンに対応するデータが書込まれる。 An external magnetic field generator (magnetic field generating film in the embodiment) 8 for writing is an upward magnetic field having a strength smaller than the coercive force of the magnetic wire 2 at room temperature but larger than the coercive force of the magnetic wire 2 at elevated temperature. is added to the magnetic wire 2. The external magnetic field generator 8 is arranged downstream of the external magnetic field generator 6 in the movement direction of the domain wall. do. The external magnetic field generator 8 is arranged inside the irradiation area 10 of the pulsed light for communication, and the area heated by the irradiation of the unit light pulse of the pulsed light for communication is magnetically coupled with the external magnetic field generator 8 . When the magnetic domain passes through the region magnetically coupled with the external magnetic field generator 8, if the temperature is raised by the bright pulse, the magnetization direction of the passing magnetic domain must be reversed upward and the temperature must be raised by the dark pulse. In this case, the magnetization direction of the passing magnetic domain is not reversed and is maintained downward. As a result, the magnetization direction of the magnetic domains passing through the magnetic coupling region with the external magnetic field generator 8 during bright pulse irradiation becomes upward, and the magnetization direction of the magnetic domains passing through the magnetic coupling region during dark pulse irradiation becomes downward. Along the length of 2, data are written corresponding to the time-series change pattern of light and dark.
　磁性細線２の保磁力は昇温すると低下することから、保磁力＝「外部磁界の強度」にまで昇温した時点で、磁性細線の磁化方向が反転する。以下では特に断らない限り、書込用の外部磁界を外部磁界と略称する。本明細書では、保磁力＝「外部磁界の強度」の関係となる温度を反転温度という。磁性細線の材質によって反転温度を選択することができ、磁性細線の周囲に配置する要素によって磁性細線の放熱性ないし断熱性を調整することができることから、単位明パルスのパルス時間（この事例では４０ｐｓｅｃ）内に磁性細線が反転温度にまで昇温する関係に設定することができる。本明細書では、明パルスの照射開始時刻から反転温度に昇温するまでの時間を要昇温時間という。例えば、明パルスの照射開始時刻から３８ｐｓｅｃだけ経過した時点で反転温度にまで上昇して反転する現象が生じるように設定することができる。この場合は、要昇温時間＝３８ｐｓｅｃとなる。要昇温時間の経過後は、明パルスの終了時まで、磁壁の移動に伴って反転磁区の長さが伸びていく。 Since the coercive force of the magnetic wire 2 decreases as the temperature rises, the magnetization direction of the magnetic wire reverses when the temperature rises to the point where the coercive force equals the "strength of the external magnetic field". Hereinafter, the external magnetic field for writing is abbreviated as the external magnetic field unless otherwise specified. In this specification, the temperature at which the relationship of coercive force=“intensity of external magnetic field” is referred to as reversal temperature. The reversal temperature can be selected according to the material of the magnetic wire, and the heat dissipation or heat insulation of the magnetic wire can be adjusted by the elements arranged around the magnetic wire. ) in which the temperature of the magnetic wire rises to the reversal temperature. In this specification, the time from the start of light pulse irradiation until the temperature is raised to the inversion temperature is referred to as the required temperature rise time. For example, it can be set so that the temperature rises to the reversal temperature and the reversal occurs when 38 psec has elapsed from the start of irradiation of the bright pulse. In this case, the required temperature rise time is 38 psec. After the required temperature rise time has elapsed, the length of the reversed magnetic domain increases with the movement of the domain wall until the end of the light pulse.
　用語の意味を整理する。
外部磁界：特に断らない限り、初期磁化用の外部磁界でなく、書込用の外部磁界をいう。
外部磁界有効領域：磁化方向を反転させる書込用の外部磁界が優越している領域をいう。
反転温度：保磁力＝「外部磁界の強度」の関係となる温度をいう。
昇温領域＝反転温度以上に昇温した領域をいう。明パルスの経過時間とともに拡大し、単位暗パルスの期間内に冷却されて消失する。
要昇温時間：明パルスの照射開始時刻から反転温度に昇温するまでの時間。 Organize the meaning of terms.
External magnetic field: Unless otherwise specified, this refers to the external magnetic field for writing, not the external magnetic field for initial magnetization.
External magnetic field effective region: A region where the external magnetic field for writing that reverses the magnetization direction is dominant.
Reversal temperature: The temperature at which the coercive force = "the strength of the external magnetic field".
Temperature rising region = A region in which the temperature is increased to the inversion temperature or higher. It expands with the elapsed time of the bright pulse and disappears by cooling within the period of the unit dark pulse.
Required temperature rise time: The time from the start of light pulse irradiation until the temperature is raised to the inversion temperature.
　本技術では、明パルス光で昇温して外部磁界の方向に反転させる現象を利用するので、昇温領域と外部磁界有効領域が重複する領域で、磁化方向が反転する。
　経過時間とともに昇温領域が外部磁界有効領域を含むように拡大する場合、昇温領域が外部磁界有効領域を含むまで拡大した時点で外部磁界有効領域内の磁性細線の磁化方向がほぼ一斉に反転する。この一斉に反転する領域の磁性細線の長さに沿った距離を「一斉反転長」という。昇温領域が外部磁界有効領域を含むように拡大する場合は、「一斉反転長」＝「外部磁界有効領域長」の関係となる。 Since the present technology utilizes a phenomenon in which the temperature is raised by bright pulse light and reversed in the direction of the external magnetic field, the magnetization direction is reversed in the region where the temperature rise region and the external magnetic field effective region overlap.
When the temperature rise region expands to include the external magnetic field effective region with the passage of time, the magnetization direction of the magnetic wires in the external magnetic field effective region reverses almost all at once when the temperature rise region expands to include the external magnetic field effective region. do. The distance along the length of the magnetic wire in which the regions are simultaneously reversed is called the "simultaneous reversal length." When the temperature rising region is expanded to include the external magnetic field effective region, the relation of "simultaneous reversal length"="external magnetic field effective region length" is established.
　外部磁界有効領域が広く、明パルス光の持続時間内に昇温領域が拡大しても、外部磁界有効領域内に留まることがある。この場合は、昇温領域の拡大に追従して反転磁区の長さが伸びていく。この場合の単位明パルスに対応する単位反転磁区長は、昇温領域のサイズよって決定される。通常は、昇温領域の拡大速度が磁区移動速度以上であることから、単位反転磁区長は明パルスの終了時点における昇温領域のサイズで決定される。 Even if the external magnetic field effective area is wide and the temperature rise area expands during the duration of the bright pulse light, it may remain within the external magnetic field effective area. In this case, the length of the reversed magnetic domain increases along with the expansion of the temperature rise region. The unit reverse magnetic domain length corresponding to the unit bright pulse in this case is determined by the size of the temperature rising region. Since the expansion speed of the temperature rising region is usually equal to or higher than the magnetic domain moving speed, the unit reversal domain length is determined by the size of the temperature rising region at the end of the bright pulse.
　図１の実施例では、昇温領域が外部磁界有効領域を含むように拡大する関係にあり、外部磁界発生装置８が磁化方向を上向きに反転させる領域の磁性細線２の長さに沿った距離が１００ｎｍに設定されている。また照射領域１０を照射する通信用パルス光の単パルス時間は４０ｐｓｅｃであり、２５Ｇｂｐｓの通信速度を持っている。 In the embodiment of FIG. 1, the temperature rising region expands to include the external magnetic field effective region. is set to 100 nm. The single pulse time of the pulsed light for communication that irradiates the irradiation area 10 is 40 psec, and has a communication speed of 25 Gbps.
　図４は、単位明パルスの照射開始時刻をゼロとした場合の温度変化を示している。８ｐｓｅｃの経過時点では、反転温度にまで昇温した領域４０－８が狭く、外部磁界発生装置８は磁化方向を上向きに反転させない。経過時間とともに反転温度にまで昇温した領域は増大する。本実施例では、３８ｐｓｅｃが経過すると、外部磁界発生装置８と磁気結合している領域が反転温度以上に昇温する。すなわち、外部磁界発生装置８と磁気結合している領域が昇温領域４０－３８内に含まれる。この結果、明パルスの照射開始時刻から３８ｐｓｅｃが経過した時点で、外部磁界発生装置８と磁気結合している領域の磁化方向がほぼ一斉に上向きに反転する。このときの反転領域の長さは１００ｍｍである。一斉反転長＝１００ｍｍである。
　本実施例では、パルス時間が４０ｐｓｅｃであり、反転後の２ｐｓｅｃの間は明パルスが持続し、その間も磁区は移動する。前記したように本実施例では、磁壁が２５００ｍ／ｓｅｃの速度で移動する電流値を磁性細線に通電するので、２ｐｓｅｃの間に５ｎｍだけ反転磁区が拡大する。結果、単位明パルスによって１０５ｎｍの長さの反転磁区が形成される。本実施例の単位反転磁区長＝１０５ｎｍである。 FIG. 4 shows the temperature change when the irradiation start time of the unit bright pulse is set to zero. When 8 psec has elapsed, the region 40-8 heated to the reversal temperature is narrow, and the external magnetic field generator 8 does not reverse the magnetization direction upward. The region heated up to the inversion temperature increases with the passage of time. In this embodiment, after 38 psec have passed, the temperature of the region magnetically coupled with the external magnetic field generator 8 rises above the reversal temperature. That is, the region magnetically coupled with the external magnetic field generator 8 is included in the temperature rising region 40-38. As a result, the magnetization directions of the regions magnetically coupled to the external magnetic field generator 8 are reversed upward almost all at once after 38 psec from the start of irradiation of the bright pulse. The length of the reversal area at this time is 100 mm. Simultaneous reversal length=100 mm.
In this embodiment, the pulse time is 40 psec, and the bright pulse lasts for 2 psec after reversal, during which the magnetic domain moves. As described above, in this embodiment, the magnetic wire is supplied with a current value that causes the domain wall to move at a speed of 2500 m/sec, so that the reversed magnetic domain expands by 5 nm in 2 psec. As a result, a 105 nm long reversed magnetic domain is formed by a unit light pulse. The unit reversal magnetic domain length in this example is 105 nm.
　昇温領域が外部磁界有効領域を含むように拡大して外部磁界有効領域でほぼ一斉に反転が生じる場合、一般に、単位反転磁区長＝一斉反転長＋磁区移動速度×（要昇温時間後の明パルス持続時間）の関係となる。 When the temperature rise region expands to include the external magnetic field effective region and reversal occurs almost all at once in the external magnetic field effective region, generally the unit reversal domain length = simultaneous reversal length + domain movement speed × (after the required temperature rise time light pulse duration).
　集光レンズ等を利用してパルス光の照射範囲を絞ったり、照射範囲内にプラズモンアンテナやヒートシンクを配置したりすることによって、単位明パルスの終了時点における昇温領域を狭めることが可能である。昇温領域を微小化することによって磁区サイズを微小化することも可能である。昇温領域を微小化することによって磁区サイズを微小化する場合は、外部磁界有効領域を狭い領域に閉じ込める必要がない。この場合は、単位明パルスの終了時点における昇温領域の長さが単位反転磁区長となる。一般的に、昇温領域の拡大速度が磁区移動速度より早いために、単位明パルスの終了時点における昇温領域の長さが単位反転磁区長となる。 It is possible to narrow the temperature rise region at the end of the unit light pulse by narrowing the irradiation range of the pulsed light using a condenser lens or placing a plasmon antenna or heat sink within the irradiation range. . It is also possible to miniaturize the magnetic domain size by miniaturizing the temperature rise region. When miniaturizing the magnetic domain size by miniaturizing the temperature rise region, it is not necessary to confine the external magnetic field effective region to a narrow region. In this case, the length of the temperature rising region at the end of the unit bright pulse is the unit reversal magnetic domain length. In general, since the expansion speed of the temperature rise region is faster than the magnetic domain movement speed, the length of the temperature rise region at the end of the unit light pulse is the unit reversal domain length.
　図３の（２）は、通信用パルス光の明暗の時系列変化例を示し、３０Ａは最短の暗パルスを示し、３２Ａは最短の明パルスを示している。両者のパルス時間は等しく、本実施例では４０ｐｓｅｃである。３０Ｂは最短の暗パルスが２個連続した暗パルスを示し、３２Ｂは最短の明パルスが２個連続した明パルスを示している。（２）の場合、「明・暗・明・明・暗・暗・明・暗・・・」の時系列変化を示し、これが本明細書でいうデータの例である。 (2) of FIG. 3 shows an example of time-series change in brightness of pulsed light for communication, 30A indicates the shortest dark pulse, and 32A indicates the shortest bright pulse. Both pulse times are equal, 40 psec in this embodiment. 30B indicates a dark pulse consisting of two consecutive shortest dark pulses, and 32B indicates a bright pulse consisting of two consecutive shortest bright pulses. In the case of (2), it shows a time-series change of "bright, dark, bright, bright, dark, dark, bright, dark...", which is an example of data referred to in this specification.
　図５は、データと、磁性細線中の磁区と磁化方向の関係を示している。（１）はパルス光が「明・暗・明・暗・・・」と変化する場合を示し、（１ａ）は磁性細線中の磁区と磁化方向の関係を示している。ハッチ付きの磁区は、外部磁界の方向に反転した反転磁区を示し、ハッチのない磁区は、外部磁界によって反転しなかった非反転磁区を示している。５１ａは明パルス５１によって形成された反転磁区を示し、５２ａは暗パルス５２に対応して残存した非反転磁区を示し、５３ａは明パルス５３によって形成された反転磁区を示し、５４ａは暗パルス５４に対応して残存した非反転磁区を示している。図５（１）に示す期間Ｔ５５はパルス時間である（本実施例では４０ｐｓｅｃ）。期間Ｔ５６は、要昇温時間である（本実施例では３８ｐｓｅｃ）。期間Ｔ５７は、図４の３８～４０ｐｓｅｃに対応する。期間Ｔ５７内に反転磁区５１ａを形成する。反転磁区５１ａの長さは、一斉反転長（本実施例では図４の１００ｎｍ）＋期間Ｔ５７内の磁区移動距離（本実施例では５ｎｍ）であり、本実施例の単位反転磁区長は１０５ｎｍである。期間Ｔ５８は、磁区を反転させない期間に相当し、その期間の長さは、パルス時間＋要昇温時間に等しい。非反転領域５２ａの長さは、（パルス時間＋要昇温時間）×磁区移動速度－「一斉反転長」となり、本実施例では９５ｎｍである。なお（パルス時間＋要昇温時間）×磁区移動速度－「一斉反転長」＝（２×パルス時間）×磁区移動速度－単位反転磁区長の関係となる。
　前記したように、本実施例の単位反転磁区長は１０５ｎｍであり、単位非反転磁区長は９５ｎｍであり、両者は相違する。 FIG. 5 shows the data and the relationship between magnetic domain and magnetization direction in the magnetic wire. (1) shows the case where the pulsed light changes "bright/dark/bright/dark...", and (1a) shows the relationship between the magnetic domains in the magnetic nanowire and the magnetization direction. A hatched magnetic domain indicates a reversed magnetic domain that is reversed in the direction of the external magnetic field, and an unhatched magnetic domain indicates a non-reversed magnetic domain that is not reversed by the external magnetic field. 51a indicates the reversed magnetic domain formed by the bright pulse 51, 52a indicates the remaining non-reversed magnetic domain corresponding to the dark pulse 52, 53a indicates the reversed magnetic domain formed by the bright pulse 53, and 54a indicates the dark pulse 54. shows the remaining non-reversed magnetic domains corresponding to . A period T55 shown in FIG. 5(1) is a pulse time (40 psec in this embodiment). A period T56 is a required temperature rise time (38 psec in this embodiment). The period T57 corresponds to 38-40 psec in FIG. The reversed magnetic domain 51a is formed within the period T57. The length of the reversed magnetic domain 51a is equal to the simultaneous reversal length (100 nm in FIG. 4 in this embodiment)+the magnetic domain movement distance within the period T57 (5 nm in this embodiment), and the unit reversed magnetic domain length in this embodiment is 105 nm. be. The period T58 corresponds to a period during which the magnetic domain is not reversed, and the length of the period is equal to the pulse time plus the required temperature rise time. The length of the non-reversal region 52a is (pulse time+required heating time)×magnetic domain moving speed−“simultaneous reversal length”, which is 95 nm in this embodiment. The relationship is (pulse time+required temperature rise time)×magnetic domain movement speed−“simultaneous reversal length”=(2×pulse time)×magnetic domain movement speed−unit reversal magnetic domain length.
As described above, the unit reversal magnetic domain length in this example is 105 nm, and the unit non-reversal magnetic domain length is 95 nm, which are different.
　図５（２）は、「暗・暗」が連続する場合を示す。期間Ｔ′５８は連続する暗パルスによって磁区を反転させない期間に相当し、それに対応する非反転磁区の長さは、（パルス時間×２＋要昇温時間）×磁区移動速度－「一斉反転長」となり、本実施例では１９５ｎｍである。
　図５（３）は、「明・明」が連続する場合を示す。期間Ｔ′５７は連続する明パルスによって磁区を反転させる期間に相当し、それに対応する反転磁区の長さは、一斉反転長（本実施例では１００ｎｍ）＋期間Ｔ′５７内の磁区移動距離（本実施例では１０５ｎｍ）であり、本実施例では２０５ｎｍである。 FIG. 5(2) shows a case where "dark/dark" continues. The period T'58 corresponds to the period during which the magnetic domain is not reversed by successive dark pulses, and the length of the corresponding non-reversed magnetic domain is (pulse time x 2 + required temperature rise time) x magnetic domain movement speed - "simultaneous reversal length". , which is 195 nm in this embodiment.
FIG. 5(3) shows a case where "bright/bright" continues. The period T'57 corresponds to the period in which the magnetic domain is reversed by successive bright pulses, and the length of the corresponding reversed magnetic domain is equal to the simultaneous reversal length (100 nm in this embodiment) + the magnetic domain movement distance within the period T'57 ( 105 nm in this embodiment) and 205 nm in this embodiment.
　図５（１ａ）（２ａ）（３ａ）に示すように、明暗の変化パターンによって磁壁位置は変化し、一定にならないが、大きくずれることはなく、例えば、位置Ｐ１は、明暗のパターンに依らず、最初のパルス５１に対応する磁区内にあり、位置Ｐ２は２個目のパルス５２に対応する磁区内にあり、位置Ｐ３は３個目のパルス５３に対応する磁区内にあり、位置Ｐ４は４個目のパルス５４に対応する磁区内にある。 As shown in FIGS. 5(1a), (2a), and (3a), the domain wall position changes depending on the light and dark change pattern, and although it does not become constant, it does not deviate greatly. For example, the position P1 is , in the magnetic domain corresponding to the first pulse 51, position P2 in the magnetic domain corresponding to the second pulse 52, position P3 in the magnetic domain corresponding to the third pulse 53, position P4 in It is in the magnetic domain corresponding to the fourth pulse 54 .
　上記を利用すると、複数ビットのデータを同時並列的に読取ことが可能となる。Ｐ１の位置に最初の磁区の磁化方向に対応して変化する値を検出するセンサを配置し、Ｐ２の位置に２個目の同一センサを配置し、Ｐ３の位置に３個目の同一センサを配置し、Ｐ４の位置に４個目の同一センサを配置しておけば、４個の磁区の磁化方向を同時並行して読取ることができる。 By using the above, it is possible to read multiple bits of data in parallel. A sensor for detecting a value that changes according to the magnetization direction of the first magnetic domain is arranged at position P1, a second identical sensor is arranged at position P2, and a third identical sensor is arranged at position P3. If a fourth identical sensor is arranged at the position P4, the magnetization directions of the four magnetic domains can be read in parallel.
　前記したように、本実施例では１ビットの書込みは４０ｐｓｅｃでできる。これに対して磁化方向に対応して変化する値を検出するセンサ（例えばTunneling Magneto Resistive, ＴＭＲ）によって磁化方向を検出するには １００ｐｓｅｃ以上を必要する。複数個のセンサで複数ビットを同時並行的に読取ることを可能にすれば、各センサによる読取処理が低速で通信速度に追従できないという問題を解決することができる。 As described above, in this embodiment, 1 bit can be written in 40 psec. On the other hand, 100 psec or more is required to detect the magnetization direction by a sensor that detects a value that changes according to the magnetization direction (for example, Tunneling Magneto Resistive, TMR). If a plurality of sensors can simultaneously read a plurality of bits, it is possible to solve the problem that the reading process by each sensor is slow and cannot keep up with the communication speed.
　本実施例では、パルス時間×磁区移動速度＝１００ｎｍであり、前記した位置Ｐ１，Ｐ２，Ｐ３，Ｐ４の間隔に等しい。本明細書では、パルス時間×磁区移動速度＝単位磁区長という。磁性細線の磁化方向に依って異なる値を検出するセンサを単位磁区長の間隔で配列しておけば、複数個の磁区の磁化方向を同時並行的に読取ることが可能となる。 In this embodiment, pulse time x magnetic domain movement speed = 100 nm, which is equal to the intervals between the positions P1, P2, P3, and P4 described above. In this specification, it is referred to as pulse time×magnetic domain movement speed=unit magnetic domain length. By arranging sensors that detect different values depending on the magnetization direction of the magnetic wire at intervals of the unit magnetic domain length, it is possible to simultaneously read the magnetization directions of a plurality of magnetic domains.
　以上で説明した用語を整理しておく。
単位磁区長：パルス時間×磁区移動速度をいう。
単位反転磁区長：単位明パルスによって形成される単位反転磁区の長さをいう。反転磁区の形成時に、昇温に時間を要したり、ほぼ一斉に反転する領域が形成されたり、昇温領域が広がりを持つために、単位磁区長から相違する。
単位非反転磁区長：単位暗パルスに対応して残留する単位非反転磁区の長さをいう。その長さは、（２×パルス時間）×磁区移動速度－単位反転磁区長である。要昇温時間の経過時にほぼ一斉に反転する現象が生じる場合は、（パルス時間＋要昇温時間）×磁区移動速度－「一斉反転長」に等しくなる。「磁区移動速度」＞「単位反転磁区長／（２×パルス時間）」の関係にあれば、単位暗パルスに対応する最小非反転磁区を挟んで隣接する２個の反転磁区の間に非反転磁区が残存し、非反転磁区が消失することがない。 Let's organize the terms explained above.
Unit magnetic domain length: Pulse time x magnetic domain moving speed.
Unit reversal domain length: The length of a unit reversal domain formed by a unit light pulse. When the reversed magnetic domains are formed, it takes time to raise the temperature, a region that reverses almost all at once is formed, and the temperature rise region has a spread.
Unit non-inverted magnetic domain length: The length of a unit non-inverted magnetic domain remaining in response to a unit dark pulse. Its length is (2×pulse time)×domain migration speed−unit reversal domain length. When the phenomenon of almost simultaneous reversal occurs when the required temperature rise time elapses, it is equal to (pulse time+required temperature rise time)×magnetic domain moving speed−“simultaneous reversal length”. If there is a relationship of "magnetic domain moving speed">"unit reversed magnetic domain length/(2 x pulse time)", then the non-reversed magnetic domain between two adjacent reversed magnetic domains sandwiching the minimum non-reversed magnetic domain corresponding to the unit dark pulse Magnetic domains remain and non-inverted magnetic domains do not disappear.
　図１の１２Ａは、１６個のＴＭＲセンサの列を示し、隣接するセンサ間の間隔は、図５の位置Ｐ１，Ｐ２，Ｐ３・・・の関係を満たす。すなわち、間隔＝単位磁区長の関係に置かれている。
　図５の（１ａ）～（３ａ）に示すように、１磁区の長さは、９５ｎｍであったり、１０５ｎｍであったりする。各磁区の長さは必ずしも単位磁区長にならない。ただし、間隔＝単位磁区長の関係を満たす間隔でセンサ群を配列しておくと、各センサが各磁区のほぼ中央に対向する位置関係を得ることができる。これによって複数の磁区の磁化方向を同時に読取ることが可能となる。 12A in FIG. 1 shows a row of 16 TMR sensors, and the spacing between adjacent sensors satisfies the relationship of positions P1, P2, P3, . . . in FIG. That is, it is placed in the relationship of interval=unit magnetic domain length.
As shown in (1a) to (3a) of FIG. 5, the length of one magnetic domain is 95 nm or 105 nm. The length of each magnetic domain does not necessarily equal the unit magnetic domain length. However, by arranging the sensor groups at intervals that satisfy the relationship of interval=unit magnetic domain length, it is possible to obtain a positional relationship in which each sensor faces approximately the center of each magnetic domain. This allows the magnetization directions of multiple magnetic domains to be read simultaneously.
　本実施例の場合、１６個の連続したパルスに対しては、磁性細線２Ａの１６個の磁区にデータを書込む。その後の１６個の連続したパルスに対しては、磁性細線２Ｂの１６個の磁区にデータを書込む。各処理に要する時間は「４０ｐｓｅｃ×１６」である。本実施例では、磁性細線２Ｂの１６個の磁区にデータを書込む間に、磁性細線２Ａの１６個の磁区の磁化方向を読取る。各センサでの処理には４０ｐｓｅｃ以上を要するが、１６ビットのデータを同時並行的に読取るために、１６ビットのデータを「４０ｐｓｅｃ×１６」以内に検出することができ、読取ったデータをＨＤＤ１７に中継することができる。各センサによるデータの読取に時間を要しても、１６ビットを同時並行して読取ることから、ＨＤＤ１７には光通信速度でデータを中継することができる。 In the case of this embodiment, data is written in 16 magnetic domains of the magnetic wire 2A for 16 consecutive pulses. For the subsequent 16 consecutive pulses, data is written into 16 magnetic domains of the magnetic wire 2B. The time required for each process is "40 psec×16". In this embodiment, the magnetization directions of the 16 magnetic domains of the magnetic wire 2A are read while data is written to the 16 magnetic domains of the magnetic wire 2B. Processing in each sensor requires 40 psec or more, but since 16-bit data is read in parallel, the 16-bit data can be detected within "40 psec x 16" and the read data is stored in the HDD 17. can be relayed. Even if it takes time to read the data by each sensor, since 16 bits are read in parallel, the data can be relayed to the HDD 17 at the optical communication speed.
　図３は、タイミングチャートを示す。（１）と（２）は通信用パルス光の明暗パタ―ンを示している。図では、理解の便宜のために（１）のクロック信号と（２）のデータ信号を分離して示したが、実際には、クロック信号・データ信号・クロック信号・データ信号が時系列的に送られてくる。図では、クロック信号を１ビットで示しているが、実際には所定のプロトコルに従った複数ビットの信号がクロック信号とされている。 FIG. 3 shows a timing chart. (1) and (2) show the light and dark patterns of pulsed light for communication. In the figure, the clock signal (1) and the data signal (2) are shown separately for the convenience of understanding. sent. In the figure, the clock signal is shown as one bit, but in reality, the clock signal is a multi-bit signal conforming to a predetermined protocol.
　本実施例では、所定タイミング（クロック信号を利用して所定タイミングの到来を判別する）でスイッチ１４Ａをオンして磁性細線２Ａに通電し、磁性細線２Ａの磁壁を移動させ始める（（３）参照）。このとき、磁性細線２Ｂでは磁壁を移動させない（（５）参照）。磁壁が移動する磁性細線２Ａに、通信用パルス光の明暗パタ―ンが長さ方向に書込まれていく。１６×４０ｐｓｅｃが経過したら、さらに所定時間（（３）の３４）だけ通電してから磁性細線２Ａへの通電を停止する。所定時間３４は、最後に外部磁界発生装置８を通過したビットが、センサ列１２Ａのうちの最上流センサに対向する位置にまで移動する時間に設定されている。通電停止時には１６個の磁区が１６個のセンサに対応して停止している状態となる。期間３６の間に１６個の磁区の磁化方向を同時並行的に読取り、読取られたデータをＨＤＤ１７に送る。ＨＤＤ１７には、データをパラレルで送ってもよいし、シリアルで送ってもよい。 In this embodiment, the switch 14A is turned on at a predetermined timing (a clock signal is used to determine the arrival of the predetermined timing) to energize the magnetic wire 2A and start moving the domain wall of the magnetic wire 2A (see (3)). ). At this time, the magnetic wire 2B does not move the domain wall (see (5)). A bright and dark pattern of the pulsed light for communication is written in the longitudinal direction on the magnetic wire 2A whose domain wall moves. After 16×40 psec has passed, the magnetic wire 2A is stopped after being energized for a predetermined time (34 in (3)). The predetermined time 34 is set to the time required for the bit that has passed the external magnetic field generator 8 last to move to the position facing the most upstream sensor in the sensor array 12A. When the energization is stopped, the 16 magnetic domains are stopped corresponding to the 16 sensors. The magnetization directions of 16 magnetic domains are read concurrently during the period 36 and the read data are sent to the HDD 17 . Data may be sent to the HDD 17 in parallel or serially.
　磁性細線２Ａに１６ビットのデータを書込んだら、スイッチ１４Ｂをオンして磁性細線２Ｂに通電し、磁性細線２Ｂの磁壁を移動させ始める（（５）参照）。磁壁が移動する磁性細線２Ｂに、通信用パルス光の明暗パタ―ンが長さ方向に書込まれていく。１６×４０ｐｓｅｃが経過したら、さらに所定時間（（５）の３８）だけ通電してから通電を停止する。所定時間３８は、最後に外部磁界発生装置８を通過したビットが、センサ列１２Ｂのうちの最上流センサに対向する位置にまで移動する時間に設定されている。通電停止時には１６個の磁区が１６個のセンサに対応して停止している状態となる。その後、磁性細線２Ｂに再びデータを書込むまでの間（この間は磁性細線２Aにデータを書込む）に、１６個の磁区の磁化方向を同時並行的に読取り、読取られたデータをＨＤＤ１７に送る。ＨＤＤ１７には、データをパラレルで送ってもよいし、シリアルで送ってもよい。
　それ以後は、「磁性細線２Ａにデータを書込ながら磁性細線２Ｂのデータを読取る」処理期間と、「磁性細線２Ｂにデータを書込ながら磁性細線２Ａのデータを読取る」処理期間を交互に切換える。スイッチ１４Ａ，１４Ｂ等は切換え装置を構成する。 After writing 16-bit data to the magnetic wire 2A, the switch 14B is turned on to energize the magnetic wire 2B and start moving the domain wall of the magnetic wire 2B (see (5)). A light-dark pattern of the pulsed light for communication is written in the longitudinal direction on the magnetic wire 2B in which the domain wall moves. When 16×40 psec has passed, the current is supplied for a predetermined time (38 in (5)), and then the current is stopped. The predetermined time 38 is set to the time required for the bit that has passed the external magnetic field generator 8 last to move to the position facing the most upstream sensor in the sensor array 12B. When the energization is stopped, the 16 magnetic domains are stopped corresponding to the 16 sensors. Thereafter, until data is written again to the magnetic wire 2B (during which data is written to the magnetic wire 2A), the magnetization directions of the 16 magnetic domains are simultaneously read and the read data is sent to the HDD 17. . Data may be sent to the HDD 17 in parallel or serially.
Thereafter, the processing period for "reading data from the magnetic wire 2B while writing data to the magnetic wire 2A" and the processing period for "reading data from the magnetic wire 2A while writing data to the magnetic wire 2B" are alternately switched. . Switches 14A, 14B, etc. constitute a switching device.
以上によって、本実施例によると、
（１）ｍＷ以下という微弱な通信用パルス光によってデータを書込める。
（２）明暗が高速（１Ｇｂｐｓ以上）に変化する通信用パルス光によってデータを書込める。
（３）データの書込みに光電変換装置を要しない。
（４）データの伝送速度よりデータの読取速度が遅いという問題には、複数ビットを同時並行的に読取る技術で対処できる。
（５）複数ビットを同時並行して読取る間のデータ記憶のために、複数本の磁性細線を時系列に従って使い分ける。
　といった特徴が発揮され、データ記憶の新しい世界が実現される。 From the above, according to this embodiment,
(1) Data can be written with a weak communication pulse light of mW or less.
(2) Data can be written by communication pulsed light whose brightness changes at high speed (1 Gbps or more).
(3) No photoelectric conversion device is required for writing data.
(4) The problem that the data reading speed is slower than the data transmission speed can be dealt with by a technique of reading a plurality of bits in parallel.
(5) Multiple magnetic wires are selectively used in chronological order for data storage while multiple bits are read in parallel.
Such features will be demonstrated, and a new world of data storage will be realized.
　なお以上はあくまで実施例であり、例示のものに限定されない。例えば、
（１）磁性細線はＲＥ－ＴＭフェリ磁性材に限られない。明の単パルスで反転温度にまで昇温し、反転温度を超えると外部磁界の方向に反転するとともに、電界を印加すると磁区（磁壁）が移動する材料であって、必要な磁区移動速度が得られものであれば利用可能である。
（２）電界を印加することによって電流が流れる磁性細線に限定されない。電界を印加しても電流が流れない磁性細線を利用してもよい。
（３）磁性細線の長手方向に通電すると磁壁が長手方向に移動する磁性細線に限定されない。磁性細線の横断面に沿った電界を印加すると磁壁が長手方向に移動する磁性細線を利用してもよい。
（４）磁性細線の本数は２本に限られず、３本以上であってもよい。
（５）光通信の速度で記録できればよく、データの読取には別の状況・技術で対処することができる場合も存在する。この場合、読取装置を省略することができ、磁性細線の本数は１本でよい。
（６）同時に読取可能なビット数は１６に限られず、これより多くても少なくてもよい。
（７）磁化方向の検出センサは、トンネル電流の検出センサに限定されず、磁気センサ・電圧センサ・電流センサ・光センサであってもよい。
（８）光通信のプロトコルによっては、単位明パルス時間と単位暗パルス時間が相違する場合がある。その場合でも「磁区移動速度」＞「単位反転磁区長／（単位明パルス時間＋単位暗パルス時間）」の関係にあれば、単位暗パルスに対応する最小非反転磁区を挟んで隣接する２個の反転磁区の間に非反転磁区が残存し、非反転磁区が消失することがない。
（９）磁性細線にデータを書込む際に、磁区移動速度が変化することがあり得る。たとえば、磁性細線に間欠的に電界を印加して磁壁を間欠的に移動させる場合がある。この場合は、前記（８）に記載した磁区移動速度は、単位明パルス時間と単位暗パルス時間を通算した合計時間について計算した磁壁の平均移動速度をいう。
（１０）反転温度以上に昇温した時に磁化方向が外部磁界の方向に変化する磁性材料に代えて、所定温度以上に昇温してから所定温度以下に冷却された時に、磁化方向が外部磁界の方向に固定される磁性材料を用いることが可能である。
（第２実施例） It should be noted that the above is merely an example, and is not limited to an example. for example,
(1) Magnetic wires are not limited to RE-TM ferrimagnetic material. A single light pulse heats up to the reversal temperature, and when the reversal temperature is exceeded, the material is reversed in the direction of the external magnetic field, and the magnetic domain (domain wall) moves when an electric field is applied. Available if available.
(2) It is not limited to magnetic wires in which current flows by applying an electric field. A magnetic wire that does not flow even when an electric field is applied may be used.
(3) The magnetic wire is not limited to a magnetic wire in which the magnetic domain wall moves in the longitudinal direction when an electric current is applied in the longitudinal direction of the magnetic wire. A magnetic wire may be used in which the magnetic domain wall moves longitudinally when an electric field is applied along the cross section of the magnetic wire.
(4) The number of magnetic wires is not limited to two, and may be three or more.
(5) It is sufficient to be able to record at the speed of optical communication, and there are cases where data reading can be dealt with by another situation or technique. In this case, the reader can be omitted, and only one magnetic wire is required.
(6) The number of bits that can be read simultaneously is not limited to 16, and may be larger or smaller.
(7) The magnetization direction detection sensor is not limited to a tunnel current detection sensor, and may be a magnetic sensor, a voltage sensor, a current sensor, or an optical sensor.
(8) The unit light pulse time and the unit dark pulse time may differ depending on the optical communication protocol. Even in that case, if there is a relationship of "magnetic domain migration speed">"unit reversed magnetic domain length/(unit bright pulse time + unit dark pulse time)", two adjacent magnetic domains sandwiching the minimum non-reversed magnetic domain corresponding to the unit dark pulse A non-reversed magnetic domain remains between the reversed magnetic domains, and the non-reversed magnetic domain does not disappear.
(9) When writing data to the magnetic wire, the magnetic domain migration speed may change. For example, an electric field may be intermittently applied to the magnetic wire to intermittently move the domain wall. In this case, the magnetic domain migration speed described in (8) above refers to the average domain wall migration speed calculated for the total time of the unit bright pulse time and the unit dark pulse time.
(10) Instead of using a magnetic material whose magnetization direction changes to the direction of the external magnetic field when heated to the reversal temperature or higher, the It is possible to use a magnetic material that is fixed in the direction of .
(Second embodiment)
　図６に示すように、書込用の外部磁界発生装置８Ａは、上向き磁界を発生させる磁化膜８ｅと、その周囲に配置された下向き磁界を発生させる磁化膜８ａ，８ｂ，８ｃ，８ｄ，８ｆの集合膜であってもよい。周囲に配置された下向き磁界を発生させる磁化膜８ａ，８ｂ，８ｃ，８ｄ，８ｆは、磁性細線２に上向き磁界を発生させる領域を狭く限定し、反転磁区の長さを微小化するのに有利である。磁区の長さが短くなると、同じ長さの磁性細線に記憶可能なデータ量が増大する。また磁壁の移動速度を低速化することができる。
（第３実施例） As shown in FIG. 6, the external magnetic field generator 8A for writing includes a magnetized film 8e that generates an upward magnetic field and magnetized films 8a, 8b, 8c, 8d, and 8f that generate a downward magnetic field disposed around it. may be an aggregate film of The magnetized films 8a, 8b, 8c, 8d, and 8f that are arranged around and generate a downward magnetic field narrowly limit the region in which the magnetic wire 2 generates an upward magnetic field, which is advantageous for miniaturizing the length of the reversed magnetic domain. is. As the domain length decreases, the amount of data that can be stored in the same length of magnetic wire increases. Also, the moving speed of the domain wall can be reduced.
(Third embodiment)
　図７の実施例では、直流電源８ａと非磁性導線８ｂによって書込用の外部磁界発生装置８を構成する。導線８ｂは、照射領域１０内において、磁性細線２Ａ，２Ｂの長さ方向に対して直交する姿勢で磁性細線２Ａ，２Ｂと立体交差する。
　導線８ｂを流れる電流によって導線８ｂの右側の領域には、上向きの磁界が発生する。上向きの外部磁界によって、磁性細線２Ａ，２Ｂの磁化方向を上向きに反転させることができる。書込用の外部磁界発生装置８となる。
　図７の場合、データの書込みに先立って、磁性細線２Ａ，２Ｂの全長に亘って下向きに磁化させておく（着磁しておく）。下向きに磁化させておく手法には限定がなく、保磁力以上の強度の下向き磁界内に磁性細線２Ａ，２Ｂをおけばよい。導電路８ｂの左側の領域には、下向きの磁界が発生する。磁性細線２Ａ，２Ｂが下向きに初期されているので、特段の問題は生じない。
（第４実施例） In the embodiment of FIG. 7, an external magnetic field generator 8 for writing is composed of a DC power source 8a and a non-magnetic lead wire 8b. The conducting wire 8b intersects the magnetic wires 2A and 2B in an orientation perpendicular to the length direction of the magnetic wires 2A and 2B in the irradiation region 10 .
An upward magnetic field is generated in the region to the right of the conductor 8b by the current flowing through the conductor 8b. An upward external magnetic field can reverse the magnetization directions of the magnetic wires 2A and 2B upward. It becomes the external magnetic field generator 8 for writing.
In the case of FIG. 7, prior to data writing, the entire length of the magnetic wires 2A and 2B is magnetized downward (magnetized). There is no limitation to the method of magnetizing the magnetic wires 2A and 2B downward, and the magnetic wires 2A and 2B may be placed in a downward magnetic field having a strength equal to or greater than the coercive force. A downward magnetic field is generated in the region on the left side of the conductive path 8b. Since the magnetic wires 2A and 2B are initially directed downward, no particular problem occurs.
(Fourth embodiment)
　図８は、基板１８と磁性細線２等の断面を示す。この記憶媒体は、通信用パルス光９の入射側から、光強度増強誘電体膜８４，薄い保護膜８３，磁性細線２，光強度増強誘電体膜８２，金属反射膜８１，基板１８の順序で積層されている。光強度増強誘電体膜８４は、通信用パルス光９の照射領域では形成されているが、磁化方向の検出センサ列１２が配置されている領域では形成されていない。磁化方向の検出センサ列１２の配置位置では、検出センサ１２と磁性細線２の距離を縮めて検出感度を高めている。
　金属反射膜８１は、磁性細線２を通過したパルス光９を磁性細線２に向けて反射し、微弱（ｍＷ以下）なパルス光によって磁性細線２を昇温できるようにする。光強度増強誘電体膜８４と光強度増強誘電体膜８２は、両者間に通信用パルス光９を閉じ込めて、微弱な通信用パルス光によって磁性細線２を昇温できるようにする。 FIG. 8 shows a cross section of the substrate 18, the magnetic wire 2, and the like. This storage medium comprises, from the incident side of the pulsed light 9 for communication, a light intensity enhancing dielectric film 84, a thin protective film 83, a magnetic wire 2, a light intensity enhancing dielectric film 82, a metal reflecting film 81, and a substrate 18 in this order. Laminated. The light intensity enhancing dielectric film 84 is formed in the irradiation area of the communication pulsed light 9, but is not formed in the area where the magnetization direction detection sensor array 12 is arranged. At the arrangement position of the detection sensor array 12 for the magnetization direction, the distance between the detection sensor 12 and the magnetic wire 2 is reduced to increase the detection sensitivity.
The metal reflective film 81 reflects the pulsed light 9 that has passed through the magnetic wire 2 toward the magnetic wire 2 so that the weak (mW or less) pulsed light can raise the temperature of the magnetic wire 2 . The light intensity enhancing dielectric film 84 and the light intensity enhancing dielectric film 82 confine the communication pulsed light 9 between them so that the weak communication pulsed light can raise the temperature of the magnetic wire 2 .
　本実施例の記憶媒体は、微弱な通信用パルス光を有効に利用する光学的な工夫に加え、微弱な通信用パルス光９によって磁性細線２を昇温しやすくするための熱特性にも配慮している。パルス光９の照射領域では厚い光強度増強誘電体膜８４を利用して断熱性を高めて磁性細線２を昇温しやすくしている。これに対して断熱が不要なデータ読取領域では、厚い光強度増強誘電体膜８４を除去して検出感度を高めている。
（第５実施例） In the storage medium of the present embodiment, in addition to the optical device that effectively utilizes the weak pulsed light for communication, consideration is also given to the thermal characteristics for making it easier to raise the temperature of the magnetic wire 2 by the weak pulsed light for communication 9. are doing. In the irradiation area of the pulsed light 9, a thick light intensity enhancing dielectric film 84 is used to improve the heat insulation property and make it easy to raise the temperature of the magnetic wire 2. FIG. On the other hand, in the data reading area where heat insulation is unnecessary, the thick light intensity enhancing dielectric film 84 is removed to increase the detection sensitivity.
(Fifth embodiment)
　図９は、通信用パルス光の照射領域１０内に１本の磁性細線２を配置する場合を示す。カーブ９１は、磁性細線の横断方向における温度分布を示し、カーブ９２は、磁性細線の長さ方向における温度分布を示している。ほぼ円形の昇温領域４０の中心近傍を磁性細線２が通過する位置関係を利用すると、反転磁区９３の形状をほぼ矩形とすることができ、書込・読取エラーの発生を抑制することができる。
（第６実施例） FIG. 9 shows a case where one magnetic wire 2 is arranged in an irradiation area 10 of pulsed light for communication. A curve 91 shows the temperature distribution in the transverse direction of the magnetic wire, and a curve 92 shows the temperature distribution in the longitudinal direction of the magnetic wire. By utilizing the positional relationship in which the magnetic wire 2 passes through the vicinity of the center of the substantially circular temperature rising region 40, the shape of the reversed magnetic domain 93 can be made substantially rectangular, and the occurrence of writing/reading errors can be suppressed. .
(Sixth embodiment)
　図１０は、昇温領域４０の左側にヒートシンク１０４を付加した例を示す。この場合、カーブ１０２に示すように、磁性細線の長さ方向における温度分布が非対象となり、照射領域１０の中心から左側では急激に温度が低下する。昇温領域４０は、前記中心から右側に広がるが、左側にはほとんど広がらない。この結果、単位反転磁区１０３の長さは短くなる。
（第７実施例） FIG. 10 shows an example in which a heat sink 104 is added to the left side of the temperature raising region 40. FIG. In this case, as shown by curve 102 , the temperature distribution in the longitudinal direction of the magnetic wire is asymmetrical, and the temperature drops sharply on the left side of the center of the irradiation area 10 . The temperature rising region 40 extends to the right from the center, but hardly extends to the left. As a result, the length of the unit reversed magnetic domain 103 is shortened.
(Seventh embodiment)
　図１１は、昇温領域４０の左側にヒートシンク１０４を付加し、右側の一部の領域に外部磁界有効領域１１８を形成した例を示す。この結果、単位反転磁区１１３の長さはさらに短くなる。
（第８実施例） FIG. 11 shows an example in which a heat sink 104 is added to the left side of the temperature raising region 40 and an external magnetic field effective region 118 is formed in a partial region on the right side. As a result, the length of the unit reversal magnetic domain 113 is further shortened.
(Eighth embodiment)
　図１２は、磁化方向検出装置１２の動作周波数と、通信用パルス光９の点滅周波数が等しい場合の実施例を示している。この場合は、１本の磁性細線２を利用すればよい。
　この実施例では、電源１５から磁区が磁性細線２中を左から右に移動する電流を流し、最上流部で初期化用の磁化膜６によって磁性細線２の磁化方向を下向きに備える。光ファイバー１２３を通過した通信用パルス光９は集光レンズ１２２によって集光され、書込用の磁化膜８と磁気結合している領域を照射する。本実施例では、単位明パルスの終了時点における昇温領域のサイズと、外部磁界有効領域のサイズがほぼ等しい関係にある。外部磁界有効領域を通過する時点で明パルスであった磁区は、昇温されて磁化膜８の磁化方向（上向き）に反転される。外部磁界有効領域を通過する時点で暗パルスであった磁区は、昇温されないために、磁化膜８の磁化方向（上向き）に反転せず、下向きの磁化方向を維持する。磁化方向検出装置１２は、通過する磁区毎に、磁化方向が上向きか下向きかを検出し、検出結果を時系列に従って出力する。この装置によると、通信用パルス光９が伝達するデータを１本の磁性細線２に記憶することができ、記録したデータを再生することができる。この実施例の磁性細線２は、光感応型磁性細線である。 FIG. 12 shows an embodiment in which the operating frequency of the magnetization direction detector 12 and the flashing frequency of the pulsed light 9 for communication are the same. In this case, one magnetic wire 2 may be used.
In this embodiment, a current is supplied from the power source 15 so that the magnetic domain moves from left to right in the magnetic wire 2, and the magnetization direction of the magnetic wire 2 is oriented downward by the magnetization film 6 for initialization at the most upstream portion. The pulsed light 9 for communication that has passed through the optical fiber 123 is condensed by the condensing lens 122 and irradiates the region magnetically coupled with the magnetized film 8 for writing. In this embodiment, the size of the temperature rising region at the end of the unit light pulse and the size of the external magnetic field effective region are in a substantially equal relationship. The magnetic domain that was a bright pulse at the time of passing through the external magnetic field effective region is heated and reversed in the magnetization direction (upward) of the magnetization film 8 . Since the magnetic domain which is a dark pulse at the time of passing through the external magnetic field effective region is not heated up, it does not reverse the magnetization direction (upward) of the magnetized film 8 and maintains the downward magnetization direction. The magnetization direction detection device 12 detects whether the magnetization direction is upward or downward for each passing magnetic domain, and outputs the detection results in time series. According to this device, the data transmitted by the pulsed light 9 for communication can be stored in one magnetic wire 2, and the recorded data can be reproduced. The magnetic wire 2 of this embodiment is a photosensitive magnetic wire.
　図１３は、図１２の実施例において、書込みに要したパワーを横軸に示し、読取れた信号の電圧を縦軸に示している。マイナス３５ｄＢｍ以上のパワーさえあれば、検出可能な強度の信号を読取ることが可能なことを示している。なおこの実験は、１Ｇｐｂｓで実行した。
　図１４は、図１２の実施例において、通電した電流密度を横軸に示し、得られた磁区移動速度を縦軸に示したものである。電流密度を増やせば磁区移動速度は増大し、５０００ｍ／ｓｅｃ以上の高速移動を実現できる。
　図１５は、受信感度を横軸に示し、データ転送速度を縦軸に示したものである。範囲１５２は従来の光通信の場合を示し、範囲１５１が本技術による場合のものである。本技術によって性能向上が得られる。
　図１６は、データの転送速度を横軸に示し、転送に要する消費電力を縦軸に示したものである。直線１６２は従来の光通信の場合を示し、直線１６１が本技術による場合のものである。本技術によって、消費電力の劇的な低減が可能となる。 FIG. 13 shows the power required for writing on the horizontal axis and the voltage of the read signal on the vertical axis in the embodiment of FIG. It shows that a signal with a detectable intensity can be read as long as the power is -35 dBm or more. Note that this experiment was performed at 1 Gpbs.
FIG. 14 shows the applied current density on the horizontal axis and the magnetic domain migration speed obtained on the vertical axis in the embodiment of FIG. If the current density is increased, the magnetic domain movement speed increases, and high-speed movement of 5000 m/sec or more can be realized.
In FIG. 15, the horizontal axis indicates the reception sensitivity, and the vertical axis indicates the data transfer rate. Range 152 indicates the case of conventional optical communication, and range 151 is the case of the present technology. This technique provides performance improvements.
In FIG. 16, the horizontal axis indicates the data transfer speed, and the vertical axis indicates the power consumption required for the transfer. A straight line 162 indicates the case of conventional optical communication, and a straight line 161 indicates the case of the present technology. This technology enables a dramatic reduction in power consumption.
　磁性細線の磁気特性に予め空間的な分布を付与することによって、磁性細線上に記録した磁区をより低電流で駆動することが可能となる。例えば、熱処理用レーザー光を磁性細線の幅方向の中央部に集光し、その集光部を磁性細線の長さ方向に移動させる。この熱処理を予め実施しておくと、磁性細線中央部の保磁力が低下し、細線中央部の磁壁が少ない電流密度で駆動できるようになる。 By giving the magnetic properties of the magnetic nanowire a spatial distribution in advance, it is possible to drive the magnetic domains recorded on the magnetic nanowire with a lower current. For example, the heat treatment laser beam is condensed at the central portion in the width direction of the magnetic wire, and the condensing portion is moved in the length direction of the magnetic wire. If this heat treatment is carried out in advance, the coercive force at the central portion of the magnetic wire is reduced, and the magnetic domain wall at the central portion of the wire can be driven at a low current density.
　波長690nmの赤色レーザーを対物レンズの開口数(NA)0.5でGdFeCo磁性細線に集光すると、細線上には1μｍφ程度の光スポットが出来る。これを1μｍ/秒で細線に沿って連続的に照射する。すると、レーザー照射前の保磁力が850Oeだったのに対し、細線中央部の保磁力は520Oeに低下した。これにより、レーザー照射前のパルス幅3nsecの磁壁駆動電流密度は3x1011A/m2、磁壁移動速度は1900m/secだったのに対し、レーザー照射後には電流密度が0.5x1011A/m2に低減し、磁壁移動速度は3000m/secにまで高速化できた。同様の現象は予め磁性細線に大きな電流密度の電流を印加しておくことでも確認できた。すなわち、上記と同じ磁性細線に電流密度40x1011A/m2を1μsec印加すると、磁性細線中央部の保磁力が680Oeにまで低減した。これにより磁壁駆動電流密度が1.8x1011A/m2にまで低減し、磁壁移動速度が2200m/secにまで高速化した。通常の3nsecパルス幅で3x1011A/m2の磁壁駆動電流パルスを磁性細線に100回印加しても磁性細線中央の保磁力は850Oeのままなので、予め大きな電流密度のロングパルス電流を印加することが磁壁移動速度向上や駆動電流密度低減に有効であることがわかった。
　この発見は本提案にとって極めて重要である。このメカニズムとして、レーザー照射や大電流印加が、磁性細線作成時の初期磁気特性のバラつきを大幅に低減させ、磁壁駆動の障害となるピンニングサイトを大幅に減少させることが考えられ、その評価には磁性細線の空間的な保磁力分布測定が有効である。 When a red laser beam with a wavelength of 690 nm is focused on a GdFeCo magnetic nanowire with a numerical aperture (NA) of 0.5 of an objective lens, a light spot of about 1 μmφ is formed on the nanowire. This is continuously irradiated along the thin line at 1 μm/sec. Then, while the coercive force was 850 Oe before laser irradiation, the coercive force at the center of the thin wire decreased to 520 Oe. As a result, the domain wall drive current density with a pulse width of 3 ns before laser irradiation was 3×10 11 A/m 2 and the domain wall moving speed was 1900 m/sec, while the current density after laser irradiation was 0.5×10 11 A/m 2 . , and the domain wall motion speed was increased to 3000m/sec. A similar phenomenon was also confirmed by applying a large current density to the magnetic wire in advance. That is, when a current density of 40×10 11 A/m 2 was applied to the same magnetic wire as above for 1 μsec, the coercive force at the center of the magnetic wire decreased to 680 Oe. As a result, the domain wall driving current density was reduced to 1.8x10 11 A/m 2 and the domain wall moving speed was increased to 2200m/sec. Even if 3x10 11 A/m 2 domain wall drive current pulses with a normal pulse width of 3 nsec are applied to the magnetic wire 100 times, the coercive force at the center of the magnetic wire remains 850 Oe, so a long pulse current with a large current density is applied in advance. It was found that this is effective for improving the domain wall motion velocity and reducing the driving current density.
This finding is of great importance to the present proposal. As a mechanism for this, it is thought that the laser irradiation and the application of a large current greatly reduce the variation in the initial magnetic properties during the fabrication of the magnetic nanowires, and greatly reduce the pinning sites that hinder the domain wall drive. Spatial coercive force distribution measurement of magnetic nanowires is effective.
（別例１）
　図１７は、４本の光ファイバー１７１ａ，１７１ｂ，１７１ｃ，１７１ｄに対する記憶装置を示している。記憶装置１７２の受光面（表面）には、図１８に示すように、４組の記憶装置が形成されている。アルファベット小文字の添え字が対応関係を示しており、例えば１０ａは光ファイバー１７１ａに対する照射範囲である。
　本実施例では、１本の光ファイバーにつき４本の磁性細線２Ａ，２Ｂ，２Ｃ，２Ｄを利用する。４本の磁性細線を利用すると、３本の磁性細線、例えば磁性細線２Ｂ，２Ｃ，２Ｄに順々にデータを書込んでいる間に、１本の磁性細線２Ａに書込んだデータを読取ればよく、読取りに関する時間制限が緩和される。
　なお１本の光ファイバーに用いる磁性細線の本数に制約はなく、図１９に示すように、１１本であってもよいし、それ以上であってもよい。 (Another example 1)
FIG. 17 shows storage for four optical fibers 171a, 171b, 171c, 171d. As shown in FIG. 18, four sets of storage devices are formed on the light receiving surface (surface) of the storage device 172 . The suffixes of lowercase letters of the alphabet indicate the correspondence, and for example, 10a is the irradiation range for the optical fiber 171a.
In this embodiment, four magnetic wires 2A, 2B, 2C and 2D are used for one optical fiber. When four magnetic wires are used, data written to one magnetic wire 2A can be read while data is written in order to three magnetic wires, for example, magnetic wires 2B, 2C, and 2D. and the time limit on reading is relaxed.
The number of magnetic wires used in one optical fiber is not limited, and may be 11 as shown in FIG. 19, or may be more.
　使用に先立って磁性細線２Ａから２Ｋの全部を下向きに着磁させておくとともに、磁性細線２Ａから２Ｋの全部にデータを記憶したら新たな記憶媒体にデータを記憶するという利用方法が可能であり、この場合は初期磁化用の磁界発生装置は不要である。図１９に示すように、照射領域１０内に、通電用の導線４と、書込用の外部磁界発生装置８を配置してもよい。 A method of use is possible in which all of the magnetic wires 2A to 2K are magnetized downward prior to use, and data is stored in a new storage medium after data is stored in all of the magnetic wires 2A to 2K. In this case, a magnetic field generator for initial magnetization is unnecessary. As shown in FIG. 19, in the irradiation area 10, the conductive wire 4 and the external magnetic field generator 8 for writing may be arranged.
　図２０から図２２に示すように、透明基板１７３の表面（パルス光の照射面）側に集光レンズ２２ａ，２２ｂ，２２ｃ，２２ｄを配置し、裏面側に磁性細線２等を配置することが可能である。この場合、透明基板にポリカーボネイトを用いると磁区移動速度が高速化する。また、樹脂基板であるために、後記するナノインプリント技術によって安価に製造することができる。 As shown in FIGS. 20 to 22, condensing lenses 22a, 22b, 22c, and 22d can be arranged on the front surface (irradiation surface of pulsed light) of a transparent substrate 173, and magnetic wires 2 and the like can be arranged on the back surface. It is possible. In this case, if polycarbonate is used for the transparent substrate, the magnetic domain movement speed is increased. Moreover, since it is a resin substrate, it can be manufactured at a low cost by the nanoimprint technology described below.
　図２３は、昇温領域４０と磁性細線２と非磁性導線４の関係を示している。本実施例では、外部磁界有効領域が広く広がっている。図２３に示すように、磁性細線２と非磁性導線４の境界は、昇温領域４０の内側にわずかに入り込んだ位置にある。製造の際には、磁性細線２のみならず、非磁性導線４の形成範囲にも、ＲＥ－ＴＭによって配線パターンを形成しておく。その後に、非磁性導線４とする部分には、イオン注入処理を施して、磁区移動能力を失わせる。イオン注入方法を採用することによって、磁性細線２と非磁性導線４の境界を昇温領域４０の内側にわずかに入り込んだ位置に調整することができる。 FIG. 23 shows the relationship between the temperature rising region 40, the magnetic wire 2, and the non-magnetic wire 4. FIG. In this embodiment, the external magnetic field effective area is wide. As shown in FIG. 23 , the boundary between the magnetic wire 2 and the non-magnetic wire 4 is located slightly inside the temperature rising region 40 . At the time of manufacture, a wiring pattern is formed by RE-TM not only in the magnetic wire 2 but also in the formation range of the non-magnetic conductive wire 4 . After that, the portion to be the non-magnetic conductor 4 is subjected to ion implantation treatment to lose the ability to move the magnetic domain. By adopting the ion implantation method, the boundary between the magnetic wire 2 and the non-magnetic wire 4 can be adjusted to a position slightly inside the temperature rising region 40 .
　本実施例によると、磁性細線２が昇温領域４０内に入り込んだ部分２αで磁性細線２の磁化方向が反転する。磁性細線２が昇温領域４０内に入り込んだ部分２αが単位反転磁区長となる。部分２αの長さの調整によって単位反転磁区長を微細化することができる。 According to this embodiment, the magnetization direction of the magnetic wire 2 is reversed at the portion 2α where the magnetic wire 2 enters the temperature rising region 40 . The portion 2α where the magnetic wire 2 enters the temperature rising region 40 becomes the unit reversal magnetic domain length. By adjusting the length of the portion 2α, the unit reversal domain length can be made finer.
　図２４は、通信用パルス光で直接に磁性細線を照射することに代え、磁性細線に磁気結合している材料に通信用パルス光を照射し、照射によってその材料が昇温し、昇温することでその材料の磁化方向が反転する現象を得、その反転現象を磁性細線に伝搬する実施例を示す。図２４の実施例では、単位明パルスの照射領域の磁化方向が外部磁界の方向に変化する材料２４２と、その材料２４２に磁気結合している磁性細線２の組み合わせで光感応型磁性細線を形成している。 In FIG. 24, instead of directly irradiating the magnetic wire with the pulsed light for communication, the material magnetically coupled to the magnetic wire is irradiated with the pulsed light for communication, and the material is heated by the irradiation, and the temperature rises. An example in which a phenomenon in which the magnetization direction of the material is reversed is obtained by this, and the reversal phenomenon is propagated to the magnetic nanowire will be shown. In the embodiment of FIG. 24, a photosensitive magnetic wire is formed by a combination of a material 242 whose magnetization direction in a region irradiated with a unit light pulse changes in the direction of the external magnetic field and a magnetic wire 2 magnetically coupled to the material 242. are doing.
　図２４において、２４２は光磁気記憶材料に多用されている多層膜であり、記録層とメモリ層を備えている。反転温度以上に昇温すると、その昇温領域内の磁化が反転し、その反転現象が外周側に伝搬する（昇温領域を超えて外周側に伝搬する）。反転温度以下に冷却されると、冷却された領域内の磁化が再び反転し（初期磁化方向に戻る）、その再反転現象が外周側に伝搬する。参照数字２４２αは、材料２４２と磁性細線２が磁気結合している領域を示し、磁性細線２の磁化方向は、部分２４２αの磁化方向に揃う。磁性細線２と材料２４２の間は、絶縁膜２４３で絶縁されているが、絶縁膜２４３は薄く、磁気結合を妨げない。 In FIG. 24, 242 is a multi-layer film frequently used in magneto-optical memory materials, comprising a recording layer and a memory layer. When the temperature rises above the reversal temperature, the magnetization in the temperature rising region is reversed, and the reversal phenomenon propagates to the outer peripheral side (transmits to the outer peripheral side beyond the temperature rising region). When cooled to the reversal temperature or less, the magnetization in the cooled region is reversed again (returns to the initial magnetization direction), and the re-reversal phenomenon propagates to the outer peripheral side. A reference numeral 242α indicates a region where the material 242 and the magnetic wire 2 are magnetically coupled, and the magnetization direction of the magnetic wire 2 is aligned with the magnetization direction of the portion 242α. The magnetic wire 2 and the material 242 are insulated by an insulating film 243, but the insulating film 243 is thin and does not interfere with magnetic coupling.
　本実施例でも、パルス光の明暗の変化パターンを、材料２４２を介して磁性細線２に書込むことができる。単位反転磁区の長さは、材料２４２と磁性細線２が磁気結合している領域の長さで調整でき、所望の長さに調整しやすい。 Also in this embodiment, it is possible to write the light-dark change pattern of the pulsed light onto the magnetic wire 2 via the material 242 . The length of the unit reversal magnetic domain can be adjusted by the length of the region where the material 242 and the magnetic wire 2 are magnetically coupled, and can be easily adjusted to a desired length.
　図２５は、磁性細線２に交差するもう１本の磁性細線２５２を利用する実施例であり、追加された磁性細線２５２をパルス光で照射する。磁性細線２と磁性細線２５２の間は、非磁性導線２５４で接続している。この非磁性導線２５４は、磁性細線にイオン注入して磁区移動能力を失わせたものである。磁性細線２と磁性細線２５２が立体交差する部分では両者間に絶縁膜２５３を介在させ、短絡回路が形成されないようにする。 FIG. 25 shows an embodiment using another magnetic wire 252 that intersects the magnetic wire 2, and the added magnetic wire 252 is irradiated with pulsed light. The magnetic wire 2 and the magnetic wire 252 are connected by a non-magnetic conductor 254 . This non-magnetic wire 254 is obtained by implanting ions into a magnetic wire to lose the ability to move magnetic domains. An insulating film 253 is interposed between the magnetic wire 2 and the magnetic wire 252 at the crossover point to prevent the formation of a short circuit.
　磁性細線２５２は、全長に亘って下向きに着磁されている。明パルスが照射領域１０を照射すると、その中心は反転温度以上に加熱される。昇温領域の周囲の磁性細線２５２は下向きに着磁されていることから、昇温領域には、その周囲の磁性細線２５２から漏洩する磁界が加えられる。下向きの磁界の中心には、上向きの磁界が生じる。この結果、昇温領域には上向きの外部磁界が作用し、その磁化方向が上向きに反転する。本実施例では、下向きに着磁された磁性細線２５２が外部磁界発生装置を兼用しており、その漏洩磁界を利用して昇温領域の磁化方向を反転させる。暗パルスの照射時には、昇温領域が形成されず、反転現象が生じない。 The magnetic wire 252 is magnetized downward over its entire length. When the light pulse irradiates the illuminated area 10, its center is heated above the inversion temperature. Since the magnetic wires 252 around the temperature rising region are magnetized downward, a magnetic field leaking from the magnetic wires 252 around the temperature rising region is applied to the temperature rising region. An upward magnetic field is generated at the center of the downward magnetic field. As a result, an upward external magnetic field acts on the temperature rising region, and the magnetization direction thereof is reversed upward. In this embodiment, the downwardly magnetized magnetic wire 252 also serves as an external magnetic field generator, and the leakage magnetic field is used to reverse the magnetization direction of the temperature rising region. When the dark pulse is applied, no temperature rise region is formed and no reversal phenomenon occurs.
　本実施例では、磁性細線２５２に、パルス光の明暗の変化パターンに対応して磁化方向が反転した磁区の並びが形成され、それが下方に移動し、磁性細線２と立体交差部分を通過する。立体交差部分を通過する際に、磁性細線２５２の磁化方向が磁性細線２に転写される。この結果、パルス光の明暗の変化パターンに対応して磁化方向が反転する磁区の並びが磁性細線２に形成され、その並びが左から右に移動する。
　本実施例によると、磁性細線２に形成される単位反転磁区の長さは、磁性細線２５２と磁性細線２が立体交差する部分の形状で調整でき、所望の長さに調整しやすい。本実施例の磁性細線２５２は光感応型であるが、磁性細線２は光感応型でなくてもよい。 In this embodiment, the magnetic wire 252 is formed with an array of magnetic domains whose magnetization directions are reversed corresponding to the light-dark change pattern of the pulsed light. . The magnetization direction of the magnetic wire 252 is transferred to the magnetic wire 2 when passing through the flyover. As a result, an array of magnetic domains whose magnetization directions are reversed corresponding to the light-dark change pattern of the pulsed light is formed in the magnetic wire 2, and the array moves from left to right.
According to this embodiment, the length of the unit reversed magnetic domain formed in the magnetic wire 2 can be adjusted by the shape of the crossover portion of the magnetic wire 252 and the magnetic wire 2, and can be easily adjusted to a desired length. Although the magnetic wire 252 of this embodiment is of a photosensitive type, the magnetic wire 2 may not be of a photosensitive type.
　図２６では、非磁性導線２６４が磁性細線２と立体交差する。非磁性導線２６４と磁性細線２には、非磁性導線２６４によって書込用の外部磁界を発生させるとともに磁性細線２内の磁壁を移動させる電流を通電する。パルス光の中心は、立体交差部分の右側にあり右側に位置する磁性細線２をよく加熱する。立体交差部分の右側では、非磁性導線２６４を流れる電流が、上向きの外部磁界を発生させる。
　この実施例では、明パルスの照射時には、立体交差部の右側の領域で昇温して磁化方向が上向きに反転する。暗パルスの照射時には、昇温しないために反転しない。この実施例では、磁性細線２内の磁壁を移動させる電流を、書込用の外部磁界を得るための電流とすることができる。
　立体交差部分の左側では電流によって下向きの磁界が発生する。磁路を配置することによって下向き磁界が磁性細線２の特定個所を集中して通過する関係を得ることができる。磁性細線の常温での保磁力以上の強度の下向き磁界を磁性細線２に印加することができ、これを初期磁化用の外部磁界とすることができる。本実施例の磁性細線２には、光感応型を用いる。 In FIG. 26, the non-magnetic conductor 264 crosses over the magnetic wire 2 . A current is applied to the non-magnetic wire 264 and the magnetic wire 2 to generate an external magnetic field for writing by the non-magnetic wire 264 and move the domain wall in the magnetic wire 2 . The center of the pulsed light is on the right side of the flyover and heats well the magnetic wire 2 located on the right side. On the right side of the flyover, the current flowing through the non-magnetic conductor 264 produces an upward external magnetic field.
In this embodiment, when the light pulse is applied, the temperature rises in the area on the right side of the grade crossing and the magnetization direction is reversed upward. When the dark pulse is applied, the temperature does not rise, so the inversion does not occur. In this embodiment, the current for moving the domain wall in the magnetic wire 2 can be the current for obtaining the external magnetic field for writing.
A downward magnetic field is generated by the current on the left side of the flyover. By arranging the magnetic path, it is possible to obtain a relationship in which the downward magnetic field concentrates and passes through a specific portion of the magnetic wire 2 . A downward magnetic field having a strength greater than the coercive force of the magnetic wire at room temperature can be applied to the magnetic wire 2, and this can be used as an external magnetic field for initial magnetization. A photosensitive type is used for the magnetic wire 2 of this embodiment.
　磁性細線に通電用パルス光を照射する場合、通電用パルス光が如何に微弱であっても、照射し続けることによって磁性細線２が劣化する懸念がある。図２７は、光ファイバー２７２の先端をＸＹアクチュエータ２７３によってＸ方向とＹ方向に変位可能としている。Ｘ方向に移動することによって、利用する磁性細線を選択することができ、Ｙ方向に移動することで照射位置を磁性細線の長さ方向に変位させことができる。これによって記憶装置の寿命を伸ばすことができる。
　図２７の場合、透明基板２７１の裏面に集光レンズ２７４を形成し、透明基板の表面に磁性細線２等を形成している。 When the magnetic wire is irradiated with the energizing pulsed light, there is a concern that the magnetic wire 2 may be degraded by continued irradiation, no matter how weak the energizing pulsed light is. 27, the tip of an optical fiber 272 can be displaced in the X and Y directions by an XY actuator 273. FIG. By moving in the X direction, the magnetic wire to be used can be selected, and by moving in the Y direction, the irradiation position can be displaced in the length direction of the magnetic wire. This can extend the life of the storage device.
In the case of FIG. 27, a condensing lens 274 is formed on the rear surface of a transparent substrate 271, and magnetic wires 2 and the like are formed on the surface of the transparent substrate.
　図２８は、透明基板２７１の裏面に集光レンズ２７４を形成し、透明基板２７１の表面に磁性細線２等を形成する過程を示している。透明基板２７１は樹脂製であり、成形型を使って成形することが可能である。集光レンズ２７４は、成形型にレンズ面を形成しておくことで成形することができる。
　本実施例では、成形型を利用して磁性細線形成領域に段差を作っておく。その段差形成領域にＲＥ－ＴＭ膜を蒸着する。段差形状を調整することによって段差の頂面に堆積したＲＥ－ＴＭ膜と、段差の底面に堆積したＲＥ－ＴＭ膜を電磁気的に絶縁すること可能である。これによって磁性細線群を量産することができる。成形型を利用するナノインプリント技術によると、記憶装置の量産性を高めて製造コストを圧縮することができる。また、頂面に堆積したＲＥ－ＴＭ膜と段差の底面に堆積したＲＥ－ＴＭ膜は、図２８の上下方向に分離されていることから、左右方向では隣接する磁性細線の間に隙間を形成する必要がない。単位面積あたりに形成可能な磁性細線の本数を高めることができる。 FIG. 28 shows a process of forming a condensing lens 274 on the back surface of the transparent substrate 271 and forming the magnetic wire 2 and the like on the surface of the transparent substrate 271 . The transparent substrate 271 is made of resin and can be molded using a mold. The condensing lens 274 can be formed by forming a lens surface in a mold.
In this embodiment, a mold is used to form a step in the magnetic wire forming region. An RE-TM film is deposited on the step forming region. By adjusting the shape of the step, it is possible to electromagnetically insulate the RE-TM film deposited on the top surface of the step from the RE-TM film deposited on the bottom surface of the step. This enables mass production of magnetic wires. According to the nanoimprint technology using a molding die, it is possible to improve mass productivity of memory devices and reduce manufacturing costs. Since the RE-TM film deposited on the top surface and the RE-TM film deposited on the bottom surface of the step are separated in the vertical direction in FIG. you don't have to. The number of magnetic wires that can be formed per unit area can be increased.
　なお、磁性細線２には、合金を利用する場合もあれば、多層膜を利用する場合もある。多層膜を利用する場合には、段差部分に対する蒸着工程を繰り返せばよく、ナノインプリントで製造することができる。 It should be noted that the magnetic wire 2 may use an alloy or may use a multilayer film. In the case of using a multilayer film, the vapor deposition process may be repeated on the stepped portion, and nanoimprinting can be used.

（他の実施形態）
　図２９に示すように、複数本の磁性細線Ａ１，Ａ２，Ａ３，Ａ４を、集光された通信用パルス光９Ａの光軸に沿って配置してもよい。各磁性細線は薄くて透明であり、光軸に沿って配置された磁性細線Ａ１，Ａ２，Ａ３，Ａ４の全部が、通信用パルス光９Ａによって反転温度以上に昇温される現象を得ることができる。この場合、磁性細線Ａ１，Ａ２，Ａ３，Ａ４の中から磁壁を移動させる電流を印加する磁性細線を選択することによって、データを書込む磁性細線を選択することができる。光軸にそって複数本の磁性細線を配置することによって記憶容量を本数分だけ増大することができる。
(Other embodiments)
As shown in FIG. 29, a plurality of magnetic wires A1, A2, A3, and A4 may be arranged along the optical axis of the condensed pulsed light for communication 9A. Each magnetic wire is thin and transparent, and all of the magnetic wires A1, A2, A3, and A4 arranged along the optical axis can be heated above the inversion temperature by the communication pulse light 9A. can. In this case, the magnetic wire for writing data can be selected by selecting the magnetic wire to which the current for moving the domain wall is applied from among the magnetic wires A1, A2, A3, and A4. By arranging a plurality of magnetic wires along the optical axis, the storage capacity can be increased by the number of wires.
　複数本の磁性細線Ａ１，Ａ２，Ａ３，Ａ４を通信用パルス光９Ａの光軸に沿って配置する場合、ＴＥＭセンサによって磁化方向を検出することが難しい。この場合は、読取用の光２９を用い、磁化方向を読取る磁性細線を選択して通電する。すると、通電された磁性細線と読取用の光２９の間で磁気光学現象が発生し、それを検出することで、通電した磁性細線の磁化方向を検出することができる。磁気光学効果を測定する場合、ある程度の光量が光検出器に入力される必要があるので、読取用の光２９に対して、一定以上の反射率や透過率が得られる光学設計が重要となる。磁性細線２の光入射側と光透過側に配置する誘電膜または反射膜を選択することによって、光検出器に入力する読取用の光２９の反射光ないし透過光の光量を確保することが可能となり、通信用パルス光９によって磁性細線２を効率よく加熱することが可能となる。両者を両立させることができる。 When arranging a plurality of magnetic wires A1, A2, A3, and A4 along the optical axis of the communication pulsed light 9A, it is difficult to detect the magnetization direction with a TEM sensor. In this case, the reading light 29 is used to select and energize the magnetic wire whose magnetization direction is to be read. Then, a magneto-optical phenomenon occurs between the energized magnetic wire and the reading light 29, and by detecting it, the magnetization direction of the energized magnetic wire can be detected. When measuring the magneto-optic effect, it is necessary to input a certain amount of light to the photodetector, so it is important to have an optical design that provides a certain level of reflectance and transmittance for the reading light 29. . By selecting dielectric films or reflective films arranged on the light incident side and the light transmitting side of the magnetic wire 2, it is possible to ensure the amount of reflected light or transmitted light of the reading light 29 input to the photodetector. Thus, the magnetic wire 2 can be efficiently heated by the pulsed light 9 for communication. Both can be compatible.
　さらに大きな記憶容量が必要な場合は、通信用パルス光９の焦点深さが光軸方向に変位可能とする。図２９の場合、９Ａ，９Ｂ，９Ｃのように、通信用パルス光９の焦点深さが３段階で調整可能な場合を示している。９Ｂは図示されていないが、９Ａと９Ｃの中間深さにある。
　図２９の場合、集光された通信光９Ａに対して４本の磁性細線Ａ１，Ａ２，Ａ３，Ａ４が配置され、集光された通信光９Ｂに対して４本の磁性細線Ｂ１，Ｂ２，Ｂ３，Ｂ４が配置され、集光された通信光９Ｃに対して４本の磁性細線Ｃ１，Ｃ２，Ｃ３，Ｃ４が配置されている。磁性細線Ａのうちのいずれかの１本に記憶する場合は、９Ａに示す焦点深さに調整し、磁性細線Ｂのうちのいずれかの１本に記憶する場合は、９Ｂに示す焦点深さに調整し、磁性細線Ｃのうちのいずれかの１本に記憶する場合は、９Ｃに示す焦点深さに調整する。例えば９Ｂ（図示されていない）に調整すると、４本の磁性細線Ａ１，Ａ２，Ａ３，Ａ４に対しては集光された通信用パルス光９Ｂが深すぎて反転温度に加熱されないし、４本の磁性細線Ｃ１，Ｃ２，Ｃ３，Ｃ４に対しては集光された通信用パルス光９Ｂが浅すぎて反転温度に加熱されない。それに対して、４本の磁性細線Ｂ１，Ｂ２，Ｂ３，Ｂ４は通信用パルス光９Ｂによって反転温度以上に加熱される。
　この場合、読取用の光２９についても焦点深さが光軸方向に変位可能とする。磁性細線Ａのうちのいずれかの１本のデータを読取る場合は、２９Ａに示す焦点深さに調整し、磁性細線Ｂのうちのいずれかの１本のデータを読取る場合は、２９Ｂに示す焦点深さに調整し、磁性細線Ｃのうちのいずれかの１本のデータを読取る場合は、２９Ｃに示す焦点深さに調整する。 If a larger storage capacity is required, the focal depth of the communication pulsed light 9 can be displaced in the optical axis direction. In the case of FIG. 29, like 9A, 9B, and 9C, the focal depth of the pulsed light for communication 9 can be adjusted in three stages. 9B is not shown but is at an intermediate depth between 9A and 9C.
In the case of FIG. 29, four magnetic wires A1, A2, A3 and A4 are arranged for the condensed communication light 9A, and four magnetic wires B1, B2, B1 and B2 are arranged for the condensed communication light 9B. B3 and B4 are arranged, and four magnetic wires C1, C2, C3 and C4 are arranged for the condensed communication light 9C. When storing in any one of the magnetic wires A, adjust the depth of focus shown in 9A, and when storing in any one of the magnetic wires B, adjust the depth of focus shown in 9B. , and if stored on any one of the magnetic wires C, the focal depth is adjusted to that shown at 9C. For example, when adjusted to 9B (not shown), the condensed communication pulse light 9B is too deep for the four magnetic wires A1, A2, A3, and A4 to be heated to the reversal temperature, and the four magnetic wires A1, A2, A3, and A4 The condensed communication pulse light 9B is too shallow for the magnetic wires C1, C2, C3, and C4, so that they are not heated to the reversal temperature. On the other hand, the four magnetic wires B1, B2, B3, and B4 are heated to the inversion temperature or higher by the communication pulsed light 9B.
In this case, the focal depth of the reading light 29 can also be displaced in the optical axis direction. When reading the data of one of the magnetic wires A, adjust the focus depth shown in 29A, and when reading the data of one of the magnetic wires B, adjust the focus shown in 29B. When adjusting the depth and reading data from any one of the magnetic wires C, adjust the depth of focus shown at 29C.
　前記したように１本の通信用光ファイバーを波長や偏光面が異なる複数種類のパルス光が通過することがある。この場合は、種類ごとのパルス光に分光することができる。そうして分光したパルス光に対して図２９の装置を適用することができる。例えば、波長がλ１のパルス光を９Ａのように集光してＡ１～Ａ４の磁性細線に記憶し、波長がλ２のパルス光を９Ｂのように集光してＢ１～Ｂ４の磁性細線に記憶し、波長がλ３のパルス光を９Ｃのように集光してＣ１～Ｃ４の磁性細線に記憶することができる。 As described above, multiple types of pulsed light with different wavelengths and polarization planes may pass through a single communication optical fiber. In this case, the light can be split into pulsed lights of different types. The apparatus of FIG. 29 can be applied to the pulsed light thus dispersed. For example, pulsed light with a wavelength of λ1 is collected as shown in 9A and stored in magnetic wires A1 to A4, and pulsed light with a wavelength of λ2 is collected as shown in 9B and stored in magnetic wires B1 to B4. Then, the pulsed light with a wavelength of λ3 can be condensed as shown in 9C and stored in the magnetic wires C1 to C4.
　図３０は、通信用パルス光９の照射領域を狭く限定するために、プラズモンアンテナを利用する実施例を示す。プラズモンアンテナ３０ａ，３０ｂを利用すると、通信用パルス光９の照射領域を３０ｃに示す狭い範囲に集中することができ、磁性細線２Ａの昇温効果を高め、反転磁区長を短くしてデータの記憶密度を高めることができる。プラズモンアンテナ３０ｄ，３０ｅを利用すると、通信用パルス光９の照射領域を３０ｆに示す狭い範囲に集中することができ、磁性細線２Ｂの昇温効果を高め、反転磁区長を短くしてデータの記憶密度を高めることができる。
　図３１に示すように、プラズモンアンテナ３１ａ，３１ｂ，３１ｃを利用して、通信用パルス光９の照射領域を、磁性細線２Ａ上の狭い領域３１ｄと磁性細線２Ｂ上の狭い領域３１ｅに集中することもできる。 FIG. 30 shows an embodiment using a plasmon antenna to narrowly limit the irradiation area of the pulsed light 9 for communication. When the plasmon antennas 30a and 30b are used, the irradiation area of the pulsed light 9 for communication can be concentrated in a narrow area indicated by 30c, which enhances the effect of raising the temperature of the magnetic wire 2A and shortens the length of the reversed magnetic domain to store data. Density can be increased. When the plasmon antennas 30d and 30e are used, the irradiation area of the pulsed light 9 for communication can be concentrated in a narrow area indicated by 30f, which enhances the effect of increasing the temperature of the magnetic wire 2B and shortens the length of the reversed magnetic domain to store data. Density can be increased.
As shown in FIG. 31, plasmon antennas 31a, 31b, and 31c are used to concentrate the irradiation area of the pulsed light for communication 9 on a narrow area 31d on the magnetic wire 2A and a narrow area 31e on the magnetic wire 2B. can also
　図３２に示すように、磁性細線２が分岐線２ａと２ｂに分岐していてもよい。この場合分岐前の磁性細線２に形成された磁区の並びが、分岐した磁性細線２ａと２ｂの両方に移動して記憶され、データのミラーリングが可能となる。分岐線の本数には制約がなく、３本以上であってもよい。また分岐点の数にも制約がなく、複数個所で分岐してもよい。 As shown in FIG. 32, the magnetic wire 2 may be branched into branch lines 2a and 2b. In this case, the array of magnetic domains formed in the magnetic wire 2 before branching is moved and stored in both the branched magnetic wires 2a and 2b, enabling data mirroring. The number of branch lines is not limited, and may be three or more. Moreover, there is no restriction on the number of branch points, and the branch may be branched at a plurality of points.
　連続した磁性細線の長さに沿った位置に応じて、磁区移動速度を変えることができる。図３２の場合、分岐前の磁性細線２には２Ｉの電流が流れ、分岐後の磁性細線２ａ，２ｂの各々にＩの電流が流れる。この結果、分岐前の磁性細線２では磁区移動速度が速く、分岐後の磁性細線２ａ、２ｂでは磁区移動速度が遅い。たとえば、分岐前の磁性細線２における磁区移動速度が２５００ｍ／ｓｅｃであり、分岐後の磁性細線２ａ、２ｂにおける磁区移動速度が１２５０ｍ／ｓｅｃであるといった現象が得られる（電流と磁区移動側は必ずしも比例しないが、比例する場合もある）。この場合、分岐前の磁性細線２における磁区３２Ａの長さが２５０ｎｍあり、分岐後の磁性細線２ａ、２ｂにおける磁区３２Ｂ，３２Ｃの長さ１２５ｎｍあるといった関係を得ることができ、記憶密度を高めることができる。 The magnetic domain migration speed can be changed according to the position along the length of the continuous magnetic wire. In the case of FIG. 32, a current of 2I flows through the magnetic wire 2 before branching, and a current of I flows through each of the magnetic wires 2a and 2b after branching. As a result, the magnetic domain migration speed is fast in the magnetic wire 2 before branching, and the magnetic domain migration speed is slow in the magnetic wires 2a and 2b after branching. For example, a phenomenon can be obtained in which the magnetic domain migration speed in the magnetic wire 2 before branching is 2500 m/sec, and the magnetic domain migration speed in the magnetic wires 2a and 2b after branching is 1250 m/sec (current and the magnetic domain migration side are not necessarily not proportional, but may be proportional). In this case, the length of the magnetic domain 32A in the magnetic wire 2 before branching is 250 nm, and the length of the magnetic domains 32B and 32C in the magnetic wires 2a and 2b after branching is 125 nm. can be done.
図３３に示すように、１本の光感応型磁性細線３３０に記憶したデータを複数本の磁性細線に分散させて転写・記憶することができる。図３３の場合は、３３１～３４６に示す（ただし３３３～３４４の参照番号の表示を省略している）１６本の磁性細線に転写・記憶する。磁性細線３３０には、領域３７０にパルス光を照射し、パルス光の明暗の変化パターンに対応して磁化方向が変化する磁区の並びを記憶する。矢印３５０は磁性細線３３０の磁区移動方向を示す。単位明パルスによって磁化方向が反転する材料を介して、磁性細線３３０に磁区の並びを記憶してもよい。
　１６本の磁性細線３３１～３４６は、磁性細線３３０における単位磁区長に対応する間隔で１本の磁性細線３３０に立体交差している。矢印３５１は磁性細線３３１～３４６の磁区移動方向を示している。
　本実施例では、データに応じて磁区の磁化方向を変える書込磁性細線３３０に対して、複数本の転写磁性細線３３１～３４６が、磁性細線３３０における単位磁区長に対応する間隔で立体交差しており、立体交差部分で磁気結合している。

　本実施例によると、第１の転写磁性細線３３１に第１，１７，３３，４９・・・ビットのデータが記憶され、第２の転写磁性細線３３２に第２，１８，３４，５０・・・ビットのデータが記憶され、第１５の転写磁性細線３４５に第１５，３１，４７，６３・・・ビットのデータが記憶され、第１６の転写磁性細線３４６に第１６，３２，４８，６４・・・ビットのデータが記憶される。
　なお図３３の３６０は、後記するＭ－ＲＡＭを示す。 As shown in FIG. 33, data stored in one photosensitive magnetic wire 330 can be transferred and stored by being distributed to a plurality of magnetic wires. In the case of FIG. 33, the information is transferred and stored in 16 magnetic wires indicated by 331 to 346 (however, reference numbers 333 to 344 are omitted). In the magnetic wire 330, a region 370 is irradiated with pulsed light, and a row of magnetic domains whose magnetization direction changes in accordance with the change pattern of light and dark of the pulsed light is stored. An arrow 350 indicates the magnetic domain movement direction of the magnetic wire 330 . The array of magnetic domains may be stored in the magnetic wire 330 through a material whose magnetization direction is reversed by a unit light pulse.
The 16 magnetic wires 331 to 346 cross over one magnetic wire 330 at intervals corresponding to the unit magnetic domain length of the magnetic wire 330 . An arrow 351 indicates the magnetic domain movement direction of the magnetic wires 331-346.
In this embodiment, a plurality of transfer magnetic wires 331 to 346 three-dimensionally cross a write magnetic wire 330 that changes the magnetization direction of the magnetic domain according to data at intervals corresponding to the unit magnetic domain length in the magnetic wire 330 . and are magnetically coupled at the flyover.

According to this embodiment, the first transfer magnetic wire 331 stores the 1st, 17th, 33rd, 49th, . The fifteenth transfer magnetic wire 345 stores the 15th, 31st, 47th, 63rd, . . . , bit data is stored.
Note that 360 in FIG. 33 denotes an M-RAM which will be described later.
　図３４は、磁性細線３３０のデータを３本の磁性細線３３１，３３２，３３３に分散して記憶するプロセスを示している。簡単のために、ここでは（ａ）に示すように、単位明パルスと単位暗パルスが交互に繰り返す場合を説明する。（ｃ）から（ｇ）は、磁性細線３３０と，転写磁性細線３３１，３３２，３３３における磁区を模式的に示しており、左下がりのハッチは、磁性細線３３０内の反転磁区を示し、右下がりのハッチは、転写磁性細線３３１，３３２，３３３内の反転磁区を示し、両者が重複する領域には、クロスハッチを付している。時刻ｔ４は、第４ビットに相当する単位暗パルスの終了時刻を示し、磁性細線３３０内の各磁区の右端が転写磁性細線３３１，３３２，３３３の右端に一致している。時刻ｔ４ａは、時刻ｔ４から磁性細線３３０内の各磁区が右進し、磁性細線３３０内の各磁区の左端が、転写磁性細線３３１，３３２，３３３の左端に一致した時刻を示している。時刻ｔ４からｔ４ａの期間は、各転写磁性細線３３１，３３２，３３３の磁性細線３３０と磁気結合している領域の磁化方向が変化しない。（ｂ）に示すように、時刻ｔ４からｔ４ａの期間内に、転写磁性細線３３１，３３２，３３３の磁区を上方に移動させる電流を通電すると、前記期間内に前記磁化方向を持つ磁区が上方に移動する。転写磁性細線３３１に第１ビットのデータが記憶され、転写磁性細線３３２に第２ビットのデータが記憶され、転写磁性細線３３２に第３ビットのデータが記憶される。 FIG. 34 shows the process of dispersing and storing the data of the magnetic wire 330 to the three magnetic wires 331, 332, and 333. For the sake of simplicity, here, as shown in (a), the case where unit bright pulses and unit dark pulses are alternately repeated will be described. (c) to (g) schematically show the magnetic domains in the magnetic wire 330 and the transfer magnetic wires 331, 332, and 333. Left-sloping hatches indicate reversed magnetic domains in the magnetic wire 330, and right-sloping hatches indicate reversed magnetic domains. hatching indicates reversed magnetic domains in the transferred magnetic wires 331, 332, and 333, and cross-hatching is given to the overlapping regions. Time t4 indicates the end time of the unit dark pulse corresponding to the fourth bit, and the right end of each magnetic domain in the magnetic wire 330 coincides with the right ends of the transferred magnetic wires 331, 332, and 333. FIG. Time t4a indicates the time when each magnetic domain in the magnetic wire 330 advances to the right from time t4 and the left end of each magnetic domain in the magnetic wire 330 coincides with the left ends of the transferred magnetic wires 331, 332, and 333. FIG. During the period from time t4 to t4a, the magnetization directions of the regions of the transfer magnetic wires 331, 332, and 333 magnetically coupled to the magnetic wire 330 do not change. As shown in (b), when a current is applied to move the magnetic domains of the transferred magnetic wires 331, 332, and 333 upward during the period from time t4 to t4a, the magnetic domains having the magnetization directions move upward during the period. Moving. The transfer magnetic wire 331 stores the first bit data, the transfer magnetic wire 332 stores the second bit data, and the transfer magnetic wire 332 stores the third bit data.
　時刻ｔ７は、第７ビットに相当する単位明パルスの終了時刻を示し、磁性細線３３０内の各磁区の右端が転写磁性細線３３１，３３２，３３３の右端に一致している。すなわち第４ビットに対応する磁区の右端が転写磁性細線３３１の右端に一致し、第５ビットに対応する磁区の右端が転写磁性細線３３２の右端に一致し、第６ビットに対応する磁区の右端が転写磁性細線３３３の右端に一致している。時刻ｔ７ａは、磁性細線３３０内の各磁区が右進し、磁性細線３３０内の各磁区の左端が転写磁性細線３３１，３３２，３３３の左端に一致した時刻を示している。すなわち、第４ビットに対応する磁区の左端が転写磁性細線３３１の左端に一致し、第５ビットに対応する磁区の左端が転写磁性細線３３２の左端に一致し、第６ビットに対応する磁区の左端が転写磁性細線３３３の左端に一致している。時刻ｔ７からｔ７ａの期間は、各転写磁性細線３３１，３３２，３３３の磁性細線３３０と磁気結合している領域の磁化方向が変化しない。（ｂ）に示すように、時刻ｔ７からｔ７ａの期間内に、磁性細線３３１，３３２，３３３の磁区を上方に移動させる電流を通電すると、前記期間内に前記磁化方向を持つ磁区は上方に移動する。転写磁性細線３３１に第４ビットのデータが新たに記憶され、転写磁性細線３３２に第５ビットのデータが新たに記憶され、転写磁性細線３３２に第６ビットのデータが新たに記憶される。 Time t7 indicates the end time of the unit bright pulse corresponding to the 7th bit, and the right end of each magnetic domain in the magnetic wire 330 coincides with the right ends of the transferred magnetic wires 331, 332, and 333. That is, the right end of the magnetic domain corresponding to the 4th bit coincides with the right end of the magnetic wire 331, the right end of the magnetic domain corresponding to the 5th bit coincides with the right end of the magnetic wire 332, and the right end of the magnetic domain corresponding to the 6th bit. coincides with the right end of the transferred magnetic wire 333 . Time t7a indicates the time when each magnetic domain in the magnetic wire 330 advances to the right and the left end of each magnetic domain in the magnetic wire 330 coincides with the left ends of the transferred magnetic wires 331, 332, and 333. FIG. That is, the left end of the magnetic domain corresponding to the 4th bit matches the left end of the magnetic wire 331, the left end of the magnetic domain corresponding to the 5th bit matches the left end of the magnetic wire 332, and the magnetic domain corresponding to the 6th bit matches the left end of the magnetic wire 331. The left end coincides with the left end of the transfer magnetic wire 333 . During the period from time t7 to t7a, the magnetization directions of the regions of the transfer magnetic wires 331, 332, and 333 magnetically coupled to the magnetic wire 330 do not change. As shown in (b), when a current is applied to move the magnetic domains of the magnetic wires 331, 332, and 333 upward during the period from t7 to t7a, the magnetic domains having the magnetization directions move upward during the period. do. The 4th bit data is newly stored in the transfer magnetic wire 331 , the 5th bit data is newly stored in the transfer magnetic wire 332 , and the 6th bit data is newly stored in the transfer magnetic wire 332 .
　上記の結果、（ｇ）に示すように、転写磁性細線３３１に第１，４・・・ビットのデータが記憶され、転写磁性細線３３２に第２，５・・・ビットのデータが記憶され、転写磁性細線３３２に第３，６・・・ビットのデータが記憶される。各転写磁性細線３３１，３３２，３３３におけるデータ伝送速度は、磁性細線３３０におけるデータ伝送速度の１／３まで遅くなっている。（ａ）（ｂ）から明らかに、転写用磁性細線には、（ａ）に示す通信用パルス光の複数パルスおきに、（ｂ）に示す電界を印可する。図３４の場合、通信用パルス光の３パルスおきに転写磁性細線に電界を印可する。

　転写磁性細線３３１，３３２，３３３では磁区が間欠的に移動し、停止期間を利用してデータを読取ることができる。またデータの読取りに利用可能な期間が長くとれ、データ読取り処理に割当てる時間を長時間化することができる。 As a result, as shown in (g), the transfer magnetic wire 331 stores 1st, 4th, . . . bits of data, the transfer magnetic wire 332 stores 2nd, 5th, . 3rd, 6th, . . . bits of data are stored in the transfer magnetic wire 332 . The data transmission speed in each of the transfer magnetic wires 331 , 332 , 333 is reduced to ⅓ of the data transmission speed in the magnetic wire 330 . As can be seen from (a) and (b), the electric field shown in (b) is applied to the magnetic wire for transfer every two or more pulses of the pulsed light for communication shown in (a). In the case of FIG. 34, an electric field is applied to the transfer magnetic wire every three pulses of the pulsed light for communication.

In the transferred magnetic wires 331, 332, and 333, the magnetic domains intermittently move, and data can be read using the stop period. In addition, the period available for reading data can be lengthened, and the time allocated for data reading processing can be lengthened.
　図１に示したセンサ１２には、ＴＭＲセンサを用いることができる。ＴＭＲセンサは、図３５に示すように、磁性細線の磁区３８０と中間層３８２と磁化方向が下向きに固定されている固定層３８４の直列抵抗をセンサ３８６によって検出する。磁区３８０と固定層３８４の磁化方向が一致していれば低抵抗となり、一致していなければ高抵抗となることから、抵抗を検出するセンサ３８６の出力によって磁性細線３８０の磁化方向を検出することができる。図３６に示すようにフリー層３９０と中間層３８２と固定層３８４とセンサ３８６が積層されている既存のＴＭＲセンサに絶縁層３８８を介して磁性細線３８０を密着させてもよい。フリー層３９０には、磁性細線３８０の磁化方向が転写される。磁区３８０の磁界方向に依ってセンサ３８６が検出する抵抗値が変化する。 A TMR sensor can be used for the sensor 12 shown in FIG. As shown in FIG. 35, the TMR sensor uses a sensor 386 to detect the series resistance of the magnetic domain 380 of the magnetic wire, the intermediate layer 382, and the fixed layer 384 whose magnetization direction is fixed downward. If the magnetization directions of the magnetic domain 380 and the pinned layer 384 match, the resistance becomes low, and if they do not match, the resistance becomes high. can be done. As shown in FIG. 36, the magnetic wire 380 may be adhered to an existing TMR sensor in which a free layer 390, an intermediate layer 382, a fixed layer 384, and a sensor 386 are laminated via an insulating layer 388. FIG. The magnetization direction of the magnetic wire 380 is transferred to the free layer 390 . The resistance value detected by the sensor 386 changes depending on the magnetic field direction of the magnetic domain 380 .
　抵抗値を検出する構造に代えて、その抵抗によってオン・オフするトランジスタに置換えることができる。図３７は図３５のセンサ３８６をトランジスタ３９２に置換えたものであり、Ｍ―ＲＡＭとなっている。図３８は、図３６と同様に、既存のＭ―ＲＡＭに絶縁層３８８を介して磁性細線３８０を密着させたものである。磁区３８０の磁化方向に依存してトランジスタ３９２はオン・オフする。たとえば、磁区３８０の磁化方向が反転していればトランジスタ３９２がオフし、磁区３８０の磁化方向が反転していなければ、トランジスタ３９２がオンする関係を得ることができる。逆に、トランジスタ３９２のオンまたはオフから、磁区３８０の磁化方向、その磁区に対応するパルスの明暗、さらには磁性細線に書込まれたデータの１，０が判明する。図３７と図３８の構造は、Ｍ―ＲＡＭそのものであり、データにランダムにアクセスして演算することを可能する。すなわち、ＨＤＤ１７に伝送する際に、データを用いた演算を可能とする。 Instead of the structure that detects the resistance value, it can be replaced with a transistor that turns on and off depending on the resistance. FIG. 37 replaces the sensor 386 of FIG. 35 with a transistor 392, resulting in an M-RAM. 38, similar to FIG. 36, a magnetic wire 380 is adhered to an existing M-RAM with an insulating layer 388 interposed therebetween. Depending on the magnetization direction of magnetic domain 380, transistor 392 is turned on or off. For example, if the magnetization direction of the magnetic domain 380 is reversed, the transistor 392 is turned off, and if the magnetization direction of the magnetic domain 380 is not reversed, the transistor 392 is turned on. Conversely, the magnetization direction of the magnetic domain 380, the brightness and darkness of the pulse corresponding to the magnetic domain, and the data 1, 0 written in the magnetic wire can be determined from the ON or OFF of the transistor 392 . The structures of FIGS. 37 and 38 are M-RAMs themselves, allowing random access to data for computation. That is, when transmitting to HDD17, the calculation using data is enabled.
　図３９に示すように、１本の通信用光ファイバー３９１を通過するデータを、複数本の光感応型磁性細線に分散して記憶することができる。図３９は、２５本の磁性細線３９２－１～３９２-２５に分散して記憶する実施例を示し、第１磁性細線に３９２－１に、第１，２６，５１・・・ビットのデータを記憶し、第２磁性細線に３９２－２に、第２，２７，５２・・・ビットのデータを記憶し、第２５磁性細線に３９２－２５に、第２５，５０，７５・・・ビットのデータを記憶する。 As shown in FIG. 39, data passing through one communication optical fiber 391 can be distributed and stored in a plurality of photosensitive magnetic wires. FIG. 39 shows an embodiment in which 25 magnetic wires 392-1 to 392-25 are distributed and stored, and 1st, 26th, 51st, . , 2nd, 27th, 52nd, . Store data.
　通信用光ファイバー３９１には、２５個のＥＯ変調器ＥＯ１～ＥＯ２５が取り付けられている。各ＥＯ変調器は、電圧を印加するか否かで、光ファイバー３９１のクラッドの屈折率が変化する現象を利用する。電圧を印加しなければ、クラッドの屈折率は通常の値であり、通信光はコアに閉じ込められた状態で光ファイバーの長さに沿って進行する。ＥＯ変調器に電圧を印加すると、クラッドの屈折率が増大し、通信光はコアからクラッドを経て光ファイバー外に漏れ出る。漏れ出た通信光が集光レンズで集光され、対応する光感応型磁性細線を照射する。 　Twenty-five EO modulators EO1 to EO25 are attached to the communication optical fiber 391. Each EO modulator utilizes the phenomenon that the refractive index of the clad of the optical fiber 391 changes depending on whether voltage is applied. With no voltage applied, the refractive index of the cladding is at its normal value, and communication light travels along the length of the optical fiber confined to the core. When a voltage is applied to the EO modulator, the refractive index of the clad increases, and communication light leaks out of the optical fiber from the core through the clad. The leaked communication light is condensed by a condensing lens and illuminates the corresponding photosensitive magnetic wire.
　本実施例では、図３９の（３）に示すように、単位明パルス時間Ｔと単位暗パルス時間Ｔがともに４０ｐｓｅｃであり、通信速度は２５Ｇｂｐｓである。コアの屈折率は１．５である。 In this embodiment, as shown in (3) of FIG. 39, both the unit bright pulse time T and the unit dark pulse time T are 40 psec, and the communication speed is 25 Gbps. The refractive index of the core is 1.5.
　図３９の（１）は、時刻ｔ１における光ファイバー３９１内の通信光の明暗の分布を示している。通信用光ファイバー３９１内における通信光速度は、真空中の光速度／コアの屈折率の関係にあることから、明領域の長さＬと暗領域の長さＬは８ｍｍとなっている。２５個のＥＯ変調器ＥＯ１～ＥＯ２５は、　明領域の長さＬと暗領域の長さＬに等しい８ｍｍの間隔で配置されている。なお矢印Ａは、明領域と暗領域の進行方向を示し、ハッチは明領域を示し、ハッチのない領域は暗領域を示している。また１，２等の数字は、ビット番号を示している。 (1) of FIG. 39 shows the distribution of brightness of the communication light in the optical fiber 391 at time t1. Since the communication light speed in the communication optical fiber 391 has a relation of light speed in vacuum/refractive index of the core, the length L of the bright region and the length L of the dark region are 8 mm. The 25 EO modulators EO1 to EO25 are arranged at intervals of 8 mm equal to the length L of the bright region and the length L of the dark region. The arrow A indicates the direction in which the bright area and the dark area advance, the hatched area indicates the bright area, and the unhatched area indicates the dark area. Numerals such as 1 and 2 indicate bit numbers.
　時刻ｔ１は、光ファイバー３９１内の明領域と暗領域（以下では総称してパルス領域という）の先端が各ＥＯ変調器の右端に一致した時刻を示している。この時刻において第１ＥＯ変調器ＥＯ１に対応するパルス領域を第１ビットとすると、第２ＥＯ変調器ＥＯ２に対して第２ビットが対応し、第２５ＥＯ変調器ＥＯ２５に対して第２５ビットが対応する位置にある。
　図３９の（２）に示す時刻ｔ１ａは、パルス領域の後端が各ＥＯ変調器の左端に一致した時刻を示している。時刻ｔ１～ｔ１ａの間は、第１ＥＯ変調器ＥＯ１に対して第１ビットが対応し続け、第２ＥＯ変調器ＥＯ２に対して第２ビットが対応し続け、第２５ＥＯ変調器ＥＯ２５に対して第２５ビットが対応し続ける位置にあることが分かる。
　時刻ｔ１～ｔ１ａの間に、ＥＯ変調器ＥＯ１～ＥＯ２５に電圧を印加すれば、第１ビットの通信光が第１磁性細線３９２－１を照射し、第２ビットの通信光が第２磁性細線３９２－２を照射し、第２５ビットの通信光が第２５磁性細線３９２－２５を照射する。磁性細線を照射する通信光が明であれば、磁性細線の照射領域の磁区は反転し、磁性細線を照射する通信光が暗であれば、磁性細線の照射領域の磁区は反転しない。ハッチ付きの磁区は反転磁区を示し、ハッチのない磁区は非反転磁区を示している。光感応型磁性細線に、通信光が伝達するデータが書き込まれる。 Time t1 indicates the time when the tips of the bright region and the dark region (hereinafter collectively referred to as pulse regions) within the optical fiber 391 coincide with the right ends of the respective EO modulators. Assuming that the pulse region corresponding to the first EO modulator EO1 at this time is the first bit, the second bit corresponds to the second EO modulator EO2 and the twenty-fifth bit corresponds to the twenty-fifth EO modulator EO25. It is in.
Time t1a shown in (2) of FIG. 39 indicates the time when the rear end of the pulse region coincides with the left end of each EO modulator. Between times t1 and t1a, the first bit continues to correspond to the first EO modulator EO1, the second bit continues to correspond to the second EO modulator EO2, and the 25th bit continues to correspond to the 25th EO modulator EO25. It can be seen that the bits remain in corresponding positions.
If a voltage is applied to the EO modulators EO1 to EO25 during times t1 to t1a, the first bit communication light irradiates the first magnetic wire 392-1, and the second bit communication light irradiates the second magnetic wire. 392-2, and the 25th bit of communication light illuminates the 25th magnetic wire 392-25. If the communication light that irradiates the magnetic wire is bright, the magnetic domains in the irradiated region of the magnetic wire are reversed, and if the communication light that irradiates the magnetic wire is dark, the magnetic domains in the irradiated region of the magnetic wire are not reversed. Hatched domains indicate reversed domains, and unhatched domains indicate non-reversed domains. Data transmitted by the communication light is written in the photosensitive magnetic wire.
　図３９の（１）における時刻ｔ２は、時刻ｔ１から４０ｐｓｅｃ×２５パルス時間だけ経過した時刻を示す。時刻ｔ２では、第１変調器ＥＯ１に対して第２６ビットが対応する位置にあり、第２ＥＯ変調器ＥＯ２に対して第２７ビットが対応する位置にあり、第２５ＥＯ変調器ＥＯ２５に対して第５０ビットが対応する位置ある。時刻ｔ２においてＥＯ変調器ＥＯ１～ＥＯ２５に電圧を印加すれば、第２６ビットのデータが第１磁性細線３９２－１に記憶され、第２７ビットのデータが第２磁性細線３９２－２に記憶され、第５０ビットのデータが第２磁性細線３９２－２５に記憶される。 Time t2 in (1) of FIG. 39 indicates the time when 40 psec×25 pulse times have elapsed from time t1. At time t2, the 26th bit is at the corresponding position for the first modulator EO1, the 27th bit is at the corresponding position for the second EO modulator EO2, and the 50th bit is at the 25th EO modulator EO25. The bits are in corresponding positions. When voltage is applied to the EO modulators EO1 to EO25 at time t2, the 26th bit data is stored in the first magnetic wire 392-1, the 27th bit data is stored in the second magnetic wire 392-2, The 50th bit of data is stored in the second magnetic wire 392-25.
　各磁性細線は、データ光が明であれば反転磁区が形成され、データ光が暗であれば非反転磁区が形成される。その磁区の磁区長はほぼ１μｍである。各磁性細線には、矢印Ｂ方向に磁区を移動させる電流を通電している。この記憶装置の場合、２５ビットごとに１回の記憶処理を実施する。記憶処理の周期は１０００ｐｓｅｃである。各磁性細線では、磁区が１μｍ／１０００ｐｓｅｃの速度（１０００ｍ/秒）で移動する電流を通電する。 In each magnetic wire, a reversed magnetic domain is formed when the data light is bright, and a non-reversed magnetic domain is formed when the data light is dark. The domain length of the magnetic domain is approximately 1 μm. A current is applied to each magnetic wire to move the magnetic domain in the arrow B direction. For this storage device, one storage operation is performed every 25 bits. The cycle of memory processing is 1000 psec. In each magnetic wire, a current is passed through which the magnetic domain moves at a speed of 1 μm/1000 psec (1000 m/sec).
　図では寸法比が不正確であるが、隣接するＥＯ変調器の間隔Ｌが８ｍｍであるのに対し、磁性細線の幅Ｗはほぼ１μｍである。そこで、図３９の（４）に示すように、隣接する磁性細線の間に１μｍの間隔Ｇを確保しながら、隣接するＥＯ変調器の間隔Ｌ内に、４０００本の磁性細線を配置することが可能である。ＥＯ変調器群に対して、磁性細線群が矢印Ａ方向に相対移動可能とすれば、４０００本の磁性細線の中からデータを記憶する磁性細線を選択することが可能となる。記憶容量を４０００倍することできる。 Although the dimensional ratio is inaccurate in the figure, the width W of the magnetic wire is approximately 1 μm, while the spacing L between adjacent EO modulators is 8 mm. Therefore, as shown in FIG. 39(4), it is possible to arrange 4000 magnetic wires within the interval L between the adjacent EO modulators while securing the interval G of 1 μm between the adjacent magnetic wires. It is possible. If the magnetic wire group can move in the direction of arrow A relative to the EO modulator group, it becomes possible to select the magnetic wire for storing data from among 4000 magnetic wires. The storage capacity can be multiplied by 4000.
　上記は一実施例であり、それに限定されない。例えば、通信速度が１００Ｇｂｐｓであり、パルス時間が１０ｐｓｅｃの場合、隣接するＥＯ変調器の間隔Ｌを２ｍｍとし、磁性細線中の磁区の移動速度を６０００ｍ／秒に調整すればよく、いずれも調整可能である。また隣接するＥＯ変調器の間隔Ｌに複数本の磁性細線を配置することもできる。 The above is an example, and is not limited to it. For example, when the communication speed is 100 Gbps and the pulse time is 10 psec, the interval L between adjacent EO modulators is 2 mm, and the movement speed of the magnetic domain in the magnetic nanowire is adjusted to 6000 m/sec, both of which are adjustable. is. Also, a plurality of magnetic wires can be arranged at intervals L between adjacent EO modulators.
１：記憶装置
２：磁性細線
４：非磁性導線
６：初期化用の外部磁界発生装置
８：書込用の外部磁界発生装置
９：通信用光ファイバーを通過したパルス光
１０：照射領域
１２：磁化方向検出装置（センサ）列
１４：スイッチ
１５：直流電源
１６：制御装置
１７：ハードディスク装置
１８：基板
１９：絶縁膜
４０：昇温領域
２４２：磁化方向反転・伝搬材料
２７３：ＸＹアクチュエータ 1: storage device 2: magnetic wire 4: non-magnetic wire 6: external magnetic field generator for initialization 8: external magnetic field generator for writing 9: pulsed light passed through optical fiber for communication 10: irradiation area 12: magnetization Direction detection device (sensor) array 14: switch 15: DC power supply 16: control device 17: hard disk device 18: substrate 19: insulating film 40: temperature rising region 242: magnetization direction reversal/propagation material 273: XY actuator

Claims (19)

  1. 光感応型磁性細線と電界印加装置と書込装置を備えており、
    前記光感応型磁性細線は、通信用パルス光が含む単位明パルスに照射されると照射領域の磁化方向が外部磁界の方向に変化するとともに電界が印加されると磁区が長さ方向に移動する性質を備えており、
    前記電界印加装置は、前記光感応型磁性細線に前記電界を印加し、
    前記書込装置は、前記通信用パルス光が明パルスのときは前記明パルスの照射による昇温と前記外部磁界を利用して前記照射領域の磁化方向を前記外部磁界の方向に変化させ、前記通信用パルス光が暗パルスのときは前記磁化方向を変化させないことを特徴とする記憶装置。     Equipped with a photosensitive magnetic nanowire, an electric field application device, and a writing device,
    When the photosensitive magnetic wire is irradiated with a unit light pulse included in the pulsed light for communication, the magnetization direction of the irradiated region changes in the direction of the external magnetic field, and when an electric field is applied, the magnetic domain moves in the length direction. has the nature of
    The electric field applying device applies the electric field to the photosensitive magnetic wire,
    When the pulsed light for communication is a bright pulse, the writing device changes the magnetization direction of the irradiation region in the direction of the external magnetic field by using the temperature rise caused by the irradiation of the bright pulse and the external magnetic field, A storage device, wherein the magnetization direction is not changed when the pulsed light for communication is a dark pulse.
  2. 単位明パルスの持続時間を単位明パルス時間とし、単位暗パルスの持続時間を単位暗パルス時間とし、単位明パルスの照射によって磁化方向が変化する領域の前記光感応型磁性細線の長さに沿った距離を単位反転磁区長としたときに、前記電界印加装置が、「磁区移動速度」＞「単位反転磁区長／（単位明パルス時間＋単位暗パルス時間）」の関係を満たす磁区移動速度をもたらす強度の電界を印加することを特徴とする請求項１に記載の記憶装置。 The duration of the unit light pulse is defined as the unit light pulse time, the duration of the unit dark pulse is defined as the unit dark pulse time, and along the length of the photosensitive magnetic wire in the region where the magnetization direction is changed by the irradiation of the unit light pulse. When the distance obtained is defined as a unit reversal magnetic domain length, the electric field applying device sets a magnetic domain migration speed that satisfies the relationship of "magnetic domain migration speed" > "unit reversal magnetic domain length/(unit bright pulse time + unit dark pulse time)". 2. The storage device of claim 1, wherein an electric field having a strength that causes a
  3. 前記光感応型磁性細線の複数本が存在し、
    前記電界印加装置が、前記電界を印加する前記光感応型磁性細線を時分割方式で選択することを特徴とする請求項１または２に記載の記憶装置。     There are a plurality of the photosensitive magnetic wires,
    3. The storage device according to claim 1, wherein the electric field applying device selects the photosensitive magnetic wires to which the electric field is applied by a time division method.
  4. 複数本の転写磁性細線と、その転写磁性細線群に電界を印加する転写用電界印加装置をさらに備えており、
    前記転写磁性細線群は、単位磁区長に対応する間隔で、前記光感応型磁性細線に磁気結合しており、
    前記転写用電界印加装置が、前記通信用パルス光の複数パルスおきに、前記転写磁性細線群に前記電界を印可することを特徴とする請求項１または２に記載の記憶装置。     It further comprises a plurality of transfer magnetic wires and a transfer electric field applying device for applying an electric field to the transfer magnetic wire group,
    The transfer magnetic wire group is magnetically coupled to the photosensitive magnetic wire at intervals corresponding to a unit magnetic domain length,
    3. The storage device according to claim 1, wherein the transfer electric field applying device applies the electric field to the transfer magnetic wire group every two or more pulses of the communication pulse light.
  5. 前記通信用パルス光が通過する光ファイバーと、複数本の前記光感応型磁性細線と、複数個のＥＯ変調器を備えており、
    前記光ファイバーに対して、前記複数個のＥＯ変調器が、前記光ファイバー内の単位パルス領域長に等しい間隔で配置されており、
    各ＥＯ変調器に対して、各光感応型磁性細線が配置されていることを特徴とする請求項１または２に記載の記憶装置。     An optical fiber through which the pulsed light for communication passes, a plurality of the photosensitive magnetic wires, and a plurality of EO modulators,
    The plurality of EO modulators are arranged with respect to the optical fiber at intervals equal to the unit pulse region length in the optical fiber,
    3. The storage device according to claim 1, wherein each photosensitive magnetic wire is arranged for each EO modulator.
  6. 前記光感応型磁性細線が、前記単位明パルスの照射領域の磁化方向が前記外部磁界の方向に変化する材料で形成されている磁性細線であることを特徴とする１～５のいずれかの１項に記載の記憶装置。 6. Any one of 1 to 5, wherein the photosensitive magnetic wire is a magnetic wire formed of a material in which the magnetization direction of the irradiation region of the unit light pulse changes in the direction of the external magnetic field. The storage device according to the item.
  7. 前記光感応型磁性細線が、前記単位明パルスの照射領域の磁化方向が前記外部磁界の方向に変化する材料と、その材料に磁気結合している磁性細線の組み合わせで形成されていることを特徴とする１～５のいずれかの１項に記載の記憶装置。 The photosensitive magnetic wire is formed of a combination of a material in which the magnetization direction of the irradiation region of the unit light pulse changes in the direction of the external magnetic field and a magnetic wire magnetically coupled to the material. 6. The storage device according to any one of 1 to 5, wherein
  8. 前記書込装置が、外部磁界発生装置を備えていることを特徴とする請求項１～７のいずれかの１項に記載の記憶装置。 8. The storage device according to any one of claims 1 to 7, wherein said writing device comprises an external magnetic field generator.
  9. 前記書込装置が、非反転領域からの漏洩磁界を前記外部磁界に利用することを特徴とする請求項１～７のいずれかの１項に記載の記憶装置。 8. The memory device according to claim 1, wherein said writing device uses a leakage magnetic field from a non-inverted region as said external magnetic field.
  10. 基板上に、通信用パルス光が含む単位明パルスに照射されると照射領域の磁化方向が外部磁界の方向に変化するとともに電界が印加されると磁区が長さ方向に移動する性質を備えている光感応型磁性細線が形成されている記憶媒体。 When the substrate is irradiated with a unit light pulse containing pulsed light for communication, the magnetization direction of the irradiated region changes in the direction of the external magnetic field, and when an electric field is applied, the magnetic domain moves in the length direction. A storage medium in which a photosensitive magnetic wire is formed.
  11. 透明基板の片側面に集光レンズが形成されており、
    前記透明基板の反対面に前記光感応型磁性細線が形成されていることを特徴とする請求項１０に記載の記憶媒体。     A condenser lens is formed on one side of the transparent substrate,
    11. A storage medium according to claim 10, wherein said photosensitive magnetic wire is formed on the opposite surface of said transparent substrate.
  12. 前記透明基板が樹脂基板であり、その樹脂基板の一部に前記集光レンズが成形されていることを特徴とする請求項１１に記載の記憶媒体。 12. The storage medium according to claim 11, wherein said transparent substrate is a resin substrate, and said condensing lens is formed on a part of said resin substrate.
  13. 前記透明基板が樹脂基板であり、その樹脂基板の一部の範囲に段差が形成されており、その範囲にＲＥ－ＴＭ膜が製膜されており、前記段差によってＲＥ－ＴＭ膜が複数本の前記光感応型磁性細線に分離されていることを特徴とする請求項１１または１２に記載の記憶媒体。 The transparent substrate is a resin substrate, a step is formed in a part of the resin substrate, an RE-TM film is formed in the range, and a plurality of RE-TM films are formed by the step. 13. The storage medium according to claim 11 or 12, wherein the photosensitive magnetic wire is separated.
  14. 前記光感応型磁性細線と室温との間の断熱性が、前記光感応型磁性細線に前記通信用パルス光を照射する領域では高く、前記光感応型磁性細線の磁化方向を検出する領域では低いことを特徴とする請求項１０～１３のいずれかの１項に記載の記憶媒体。 The heat insulation between the photosensitive magnetic wire and room temperature is high in the region where the photosensitive magnetic wire is irradiated with the communication pulsed light, and is low in the region where the magnetization direction of the photosensitive magnetic wire is detected. The storage medium according to any one of claims 10 to 13, characterized in that:
  15. 前記光感応型磁性細線に前記通信用パルス光を照射する領域の一部にヒートシンクが形成されていることを特徴とする請求項１０～１３のいずれかの１項に記載の記憶媒体。 14. The storage medium according to any one of claims 10 to 13, wherein a heat sink is formed in a part of the region where the pulsed light for communication is applied to the photosensitive magnetic wire.
  16. 前記光感応型磁性細線の磁化方向を検出する検出装置を備えており、
    前記検出装置が、前記光感応型磁性細線の磁化方向に依存してオン・オフするトランジスタを備えていることを特徴とする請求項１０～１５のいずれかの１項に記載の記憶媒体。     A detection device for detecting the magnetization direction of the photosensitive magnetic wire is provided,
    16. The storage medium according to any one of claims 10 to 15, wherein said detection device comprises a transistor that turns on and off depending on the magnetization direction of said photosensitive magnetic wire.
  17. 前記光感応型磁性細線の磁化方向を検出する検出装置の複数個を備えていることを特徴とする請求項１０～１６のいずれかの１項に記載の記憶媒体。 17. The storage medium according to any one of claims 10 to 16, comprising a plurality of detection devices for detecting the magnetization direction of said photosensitive magnetic wire.
  18. 成形型を使って、集光レンズを成形した透明樹脂基板を成形する工程と、
    前記透明樹脂基板上に光感応型磁性細線を製造する工程を備えている記憶媒体製造方法。     a step of molding a transparent resin substrate having a condensing lens molded thereon using a molding die;
    A storage medium manufacturing method comprising the step of manufacturing a photosensitive magnetic wire on the transparent resin substrate.
  19. 成形型を使って、一部の領域に段差が成形されている樹脂基板を成形する工程と、
    前記樹脂基板の段差成形領域に製膜して複数本の光感応型磁性細線を製造する工程を備えている記憶媒体製造方法。     using a molding die to mold a resin substrate having a step formed in a part of the substrate;
    A storage medium manufacturing method comprising the step of manufacturing a plurality of photosensitive magnetic wires by forming a film on the stepped region of the resin substrate.
PCT/JP2022/024822 2021-07-07 2022-06-22 Storage device, storage medium, and manufacturing method for same WO2023282057A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2021-113060 2021-07-07
JP2021113060A JP2023009623A (en) 2021-07-07 2021-07-07 Storage device, storage medium, and manufacturing method thereof

Publications (1)

Publication Number Publication Date
WO2023282057A1 true WO2023282057A1 (en) 2023-01-12

Family

ID=84800249

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2022/024822 WO2023282057A1 (en) 2021-07-07 2022-06-22 Storage device, storage medium, and manufacturing method for same

Country Status (2)

Country Link
JP (1) JP2023009623A (en)
WO (1) WO2023282057A1 (en)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003203325A (en) * 2001-12-28 2003-07-18 Fujitsu Ltd Master medium for magnetic transfer, magnetic transfer recording method, slave medium for magnetic recording, and method for manufacturing master medium for magnetic transfer
JP2009060057A (en) * 2007-09-03 2009-03-19 Osaka Univ Optical assist type magnetic recorder
JP2009164447A (en) * 2008-01-09 2009-07-23 National Institute Of Advanced Industrial & Technology Nonvolatile optical memory element, and operating method thereof
JP2010263229A (en) * 2004-09-09 2010-11-18 Hokkaido Univ Magnetic recording apparatus
JP2016114813A (en) * 2014-12-16 2016-06-23 日本放送協会 Magnetic thin line device, and manufacturing method of magnetic thin line mounting substrate
JP2016201154A (en) * 2015-04-07 2016-12-01 日本放送協会 Magnetic thin wire device
JP2017011135A (en) * 2015-06-23 2017-01-12 国立大学法人秋田大学 Electric field recording magnetic memory
JP2019106287A (en) * 2017-12-12 2019-06-27 Ａｇｃ株式会社 Optical member, planar light-emitting device and display device

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003203325A (en) * 2001-12-28 2003-07-18 Fujitsu Ltd Master medium for magnetic transfer, magnetic transfer recording method, slave medium for magnetic recording, and method for manufacturing master medium for magnetic transfer
JP2010263229A (en) * 2004-09-09 2010-11-18 Hokkaido Univ Magnetic recording apparatus
JP2009060057A (en) * 2007-09-03 2009-03-19 Osaka Univ Optical assist type magnetic recorder
JP2009164447A (en) * 2008-01-09 2009-07-23 National Institute Of Advanced Industrial & Technology Nonvolatile optical memory element, and operating method thereof
JP2016114813A (en) * 2014-12-16 2016-06-23 日本放送協会 Magnetic thin line device, and manufacturing method of magnetic thin line mounting substrate
JP2016201154A (en) * 2015-04-07 2016-12-01 日本放送協会 Magnetic thin wire device
JP2017011135A (en) * 2015-06-23 2017-01-12 国立大学法人秋田大学 Electric field recording magnetic memory
JP2019106287A (en) * 2017-12-12 2019-06-27 Ａｇｃ株式会社 Optical member, planar light-emitting device and display device

Also Published As

Publication number Publication date
JP2023009623A (en) 2023-01-20

Similar Documents

Publication Publication Date Title
US7898908B2 (en) Head for thermally assisted magnetic recording device and thermally assisted magnetic recording device
US8169879B2 (en) Optical recording system to record information with light
JP2006332218A (en) Magnetic recording apparatus using heat assist type spin injection magnetization reversal
JP5345091B2 (en) Information storage device and operation method thereof
CN101097748B (en) Near-field optical transducers having a tilted metallic pin
EP0126596A2 (en) Magneto-optic recording apparatus
JP2007184075A (en) Heat assisted magnetic recording head
JP4436881B2 (en) Magnetic recording medium, magnetic recording / reproducing apparatus, and magnetic recording / reproducing method
JP2000195002A (en) Optically-assisted magnetic recording apparatus
WO2023282057A1 (en) Storage device, storage medium, and manufacturing method for same
KR101438147B1 (en) Information storage device using magnetic domain wall movement and methods of operating and manufacturing the same
US5086409A (en) Recording and/or reproducing method of bloch line memory
US6721237B2 (en) Composite magnetic head device for magnetic recording device
JP4509941B2 (en) Optical assist magnetic head and magnetic recording apparatus using the same
JP7174563B2 (en) recording device
US3911411A (en) Magnetic domain systems using different types of domains
JP2005175202A (en) Recording element
Miyamoto et al. Formation, Shift and Magneto-optical Detection of Magnetic Domain Queue in Magnetic Nanowire Memory
Mansuripur Rewritable optical disk technologies
KR100839571B1 (en) Optical element, optical head and signal reproducing method
US20230368840A1 (en) Magneto-optical memory interface
JP4998894B2 (en) Magnetic recording medium, magnetic recording / reproducing apparatus, and magnetic information recording method
US5436861A (en) Vertical bloch line memory
JP7174564B2 (en) DATA RECORDING METHOD AND RECORDING DEVICE FOR DOMAIN WALL MOVEMENT DEVICE
JPH0582678B2 (en)

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22837474

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE