KR20040034366A - Magnetic medium using spin-polarized electron and Apparatus of recording data and Recording method using the same - Google Patents

Abstract

PURPOSE: A magnetic media, and a data record system and method using the same magnetic media are provided to record data at a high speed by injecting electrons having one way spin into a high density and large capacity magnetic media which records data by using a probe. CONSTITUTION: The system comprises a magnetic media(115), a probe(111), a controller(117) and a light source(113). In order to record data on a record layer(115a) of the magnetic media(115), the probe(111) is contacted with the record layer(115a), and a power is supplied to a tip(111a) of the probe(111). At the same time, the light source(113), positioned over the probe(111), projects polarized lights, and then electrons excited at the tip(111a) become one way spin polarized electrons. The spin polarized electrons are discharged and are injected into the record layer(115a). A cantilever(111b) of the probe(111) plays a role of moving a position of the tip(111a) according to a signal from the controller(117). The record layer(115a) is composed of high strength magnetic material.

Description

Magnetic medium using spin-polarized electrons and information recording apparatus and recording method using magnetic medium {Magnetic medium using spin-polarized electron and Apparatus of recording data and Recording method using the same}

The present invention relates to a magnetic medium, an information recording apparatus for a magnetic medium, and a recording method, and more particularly, to a magnetic medium using electron spin-dependent scattering, an information recording apparatus for a magnetic medium, and a recording method.

When a magnetic medium is used as a recording medium in a conventional information storage device, information is recorded by inverting magnetization by a magnetic field. However, in the conventional information storage device, as the recording density increases, the bit size, which is the smallest unit of information recording, becomes small, and accordingly, the magnetic field to be recorded must be smaller to focus on a smaller area corresponding to the bit size. There was a contradiction that the magnitude of the magnetic field needed to reverse the magnetization of the magnetic layer also had to increase as the size of.

In order to overcome the technical problems of the prior art, US Patent No. 6,304,481 proposes an information storage device and a reproducing method using spin-polarized electrons.

1 is a cross-sectional view showing the information storage device disclosed in the US patent.

Referring to FIG. 1, the information storage device disclosed in the U.S. patent includes a control device 1, a spin polarized electron source 40 having a tip 2b, an extractor 4, and a collimator 6, 7, 9. ), Electrostatic lenses 10, 11, 12, and insulating elements 5, 8 are provided. The information storage device also includes a blanking element 13, sparse and fine micro deflectors 14 and 15, an electron detector 16, an information storage layer 17, and a substrate 18.

The control device 1 receives the control signals and information of the external device through ADDRESS IN, DATA IN, DATA OUT, decrypts them using the necessary protocol, and then transmits the control response and information again.

The electron source 40 provides spin polarized electrons 3, and the tip 2b focuses the spin polarized electrons. The extractor 4 extracts the spin-polarized electrons 3 from the tip 2b, and the collimators 6, 7, 9 focus the spin polarized electrons 3 onto the spin polarized electron beam 19. . The electrostatic lenses 10, 11, 12 focus the spin polarized electron beam 19 and the micro deflectors 14, 15 generate the electron beam 19 in a portion of the information storage layer 17 where information is to be stored. Deflect into the magnetic field.

The information storage layer 17 includes a conductive member 27 including a plurality of alignment regions 22 and insulated from the information storage layer 17 by an insulator 28.

Controller 1 applies voltage V1 to electron source 40 and applies voltages V2-V5 to obtain the desired properties of spin polarized electrons 3 and spin polarized electron beams 19. . The voltages V6-V8 are applied to the electrostatic lenses 10, 11, 12 by the controller 1 to generate an electric field passing through the lens aperture. The voltages V12-V19 are applied to one end of the stigmator element 25 by the controller 1. The controller 1 applies the signal S19 to the electron source 40 to determine the spin-polarization direction of the electrons 3, and the signals S2-S17 to the deflectors 14, 15 to produce an electron beam. Deflect (19). The control device 1 also applies the signal S1 to the blanking element 13, alternately detects the signals S18 and S20, and reproduces the information.

Since the information storage device disclosed in the US patent has to finely adjust the voltage in order to focus the electron beam on a specific information area, it is not easy to control and it is difficult to precisely output a signal for recording information, so that information reproduction is not easy. In addition, since the conventional magnetic medium is used as it is, there is a limit to increase the information recording density of the magnetic medium, and the configuration of the device has a disadvantage of complexity.

Accordingly, the technical problem to be achieved by the present invention is to improve the above-described problems of the prior art, in which a high-density large-capacity magnetic medium in which information is recorded by injecting electrons having one-direction spin, and spin in one direction to the magnetic medium. It is to provide an information recording apparatus and an information recording method for recording information at a high speed by using a probe for injecting electrons.

1 is a view showing an information storage device disclosed in US Patent No. 6,304,481;

2 is a configuration diagram schematically showing an information recording apparatus according to a first embodiment of the present invention;

3 is a configuration diagram schematically showing an information recording apparatus according to a second embodiment of the present invention;

4A is a configuration diagram schematically showing a magnetic medium according to a first embodiment of the present invention and an information recording apparatus according to a third embodiment of the present invention for recording information thereon;

4B is a schematic diagram showing an information recording apparatus in a fourth embodiment of the present invention for recording information on a magnetic medium and information therein according to the second embodiment of the present invention;

<Code Description of Main Parts of Drawing>

111, 121; Probes 111a, 121a; tip

111b, 121b; Cantilever 115, 125, 135; Magnetic media

115a, 125a, 135a; Recording layers 115b, 125b, 135b; Board

124, 134; Polarization layer

The present invention to achieve the above technical problem,

A light source for emitting circularly polarized light; And

And a probe for recording information by injecting electrons spin-polarized by the circular polarization into a magnetic medium to change the magnetization direction of the recording layer.

It is preferable that the said light source is a laser.

The present invention also to achieve the above technical problem,

And a tip capped with a magnetic film for spin polarizing electrons, and a probe for recording information by injecting the electrons into a magnetic medium to change the magnetization direction of the recording layer.

The present invention also to achieve the above technical problem,

A magnetic medium comprising a polarization layer for spin polarizing electrons and a recording layer whose magnetization direction is changed in accordance with the spin polarization direction of electrons spin-polarized by the polarization layer; And

And a probe for recording information while moving on the magnetic medium.

The present invention to achieve the above technical problem

A polarization layer for spin polarizing electrons; And

And a recording layer whose magnetization direction changes in accordance with the spin polarization direction of the electrons.

The present invention to achieve the above technical problem,

A first step of spin polarizing electrons injected into the probe; And

And a second step of recording information by changing the magnetization direction of the recording layer of the magnetic medium in accordance with the spin polarization direction of the electrons.

The probe can be circularly polarized by irradiating circularly polarized light, and it is preferable to use laser light as the circularly polarized light.

A tip capping the magnetic film for spin polarizing electrons may be formed in the probe.

The present invention also to achieve the above technical problem,

A first step of providing a magnetic medium having a recording layer and a polarization layer, and a probe moving on the magnetic medium to record information;

And spin-polarizing the electrons by the polarization layer, and then recording information by changing the magnetization direction of the recording layer according to the spin polarization direction of the electrons. do.

Electrons may be injected through the probe or the magnetic medium.

The recording layer and the polarization layer have horizontal magnetic anisotropy or vertical magnetic anisotropy.

The recording layer and the polarization layer may be formed as a continuous thin film layer, or may be formed by patterning all or part of the thin film layer.

The recording layer and the polarization layer may be thin film layers made of nanoparticles.

The recording layer and the polarization layer may further form an oxide layer through which electrons tunnel, or an oxide layer through which electrons tunnel on each surface.

The recording layer and the polarization layer may further form a metal layer at an interface.

The present invention provides a magnetic medium having a recording layer made of a magnetic material whose magnetization direction is changed depending on spin momentum or spin-spin torque by using spin polarized current, and one direction in the magnetic medium. Provided are an information recording apparatus and an information recording method capable of recording information at high speed with a simple configuration by injecting electrons having a spin of.

Hereinafter, a magnetic medium, an information recording apparatus and an information recording method according to an embodiment of the present invention will be described in detail with reference to the drawings.

2 is a schematic diagram showing an information recording apparatus according to a first embodiment of the present invention.

2, the information recording apparatus according to the first embodiment of the present invention includes a magnetic medium 115 having a substrate 115b, a magnetic recording layer 115a stacked on an upper surface of the substrate 115b, A probe 111 having a tip 111a and a cantilever 111b at one end thereof, an electrical contact with the probe 111 and the magnetic medium 115, and a current applied to the probe 111. The control unit 117 is included.

In order to record information in the recording layer 115a of the magnetic medium 115, the probe 111 is contacted with the recording layer 115a and a voltage is applied from the power supply 117 to the tip 111a. At the same time, when the left circularly polarized light or the right circularly polarized light is irradiated from the light source 113 positioned above the probe 111, the electrons excited at the tip 111a are spin-polarized in one direction by polarization. Spin-polarized electrons are emitted from the tip 111a and injected into the recording layer 115a. The spin momentum of each electron is transferred to the bits of the recording layer or changes the magnetization direction of the bits by spin-spin torque.

As the tip 111a, a general semiconductor tip or a tip made of a conductive metal may be used. The cantilever 111b serves to move the position of the tip 111a according to a signal applied from the controller 117. The controller 117 may be provided with a general circuit for controlling the position of the cantilever 111b and for adjusting the current.

The recording layer 115a may be made of a ferromagnetic material having horizontal magnetic anisotropy or vertical magnetic anisotropy, or may be made of a continuous thin film layer or a thin film layer having bits formed of nanoparticles. The recording layer 115a may be patterned in whole or in part. The interface between the substrate 115b and the recording layer 115a may further include a magnetic layer in which the magnetization direction is fixed in one direction.

A laser may be used as the light source 113. In order to irradiate circularly polarized light, the light source 113 includes a polarizer separately. Electrons spin-polarize in the direction of circular polarization, and the magnetization direction of the recording layer 115a changes in accordance with the spin polarization direction.

3 is a diagram showing an information recording apparatus and method according to a second embodiment of the present invention.

Referring to FIG. 3, the information recording apparatus according to the second embodiment of the present invention includes a probe 121 capped by a tip 123 having a magnetization direction in one direction, and a spin in one direction through the probe 121. Injecting the electrons into the magnetic medium 125 and the probe 121 in which the magnetization direction of the bit contacted by the probe 121 in the magnetic recording layer 125a changes in the same manner as the spin polarization direction while the polarized electrons are injected. And a control unit 127 for applying a current. Spin-polarized electrons change the magnetization direction of the magnetic recording layer 125a by transfer of spin momentum or by torque between spins. Here, the magnetic medium 125 may use a magnetic medium that is generally used, or may use any of various magnetic media having the magnetic layer as a recording layer. In the figure, the recording layer 125a has bits made of nanoparticles.

4A is a diagram showing a magnetic medium according to the first embodiment of the present invention and an information recording apparatus according to the third embodiment of the present invention having the same.

Referring to FIG. 4A, a magnetic medium according to a first embodiment of the present invention may be formed on a substrate 135b, a magnetic recording layer 135a stacked on an upper surface of the substrate 135b, and an upper surface of the magnetic recording layer 135a. A polarization layer 134 is provided. The polarization layer 134 is a magnetic layer having a magnetization direction in one direction. The polarization layer 134 spins and polarizes electrons injected from the probe 131 in the same direction to pass through the recording layer 135a. The recording layer 135a may be formed as a continuous thin film layer or may be patterned in whole or in part, and bits may be formed of nanoparticles to change the magnetization direction in synchronization with the spin polarization direction of electrons spin-polarized by the polarization layer 134. Information is recorded in predetermined bits.

In the information recording apparatus according to the third embodiment of the present invention, a cantilever for attaching a general conductive tip 131a and a tip 131a to one end in order to record information on the magnetic medium 135 according to the embodiment of the present invention. A probe 131 having a 131b and a control unit 137 for applying a current to the probe 131 are provided. The control unit 137 moves the cantilever 131b on the X-axis or Y-axis above the polarization layer 134 in order to record information in the bits of the recording layer 135a of the magnetic medium 135. A circuit is formed from the tip 131a through the magnetic medium 135 to cover the control unit 137, and electrons are injected into the magnetic medium 135 through the tip 131a. The injected electrons are spin-polarized through the polarization layer 134 of the magnetic medium 135, and information is recorded by changing the magnetization direction of the bits of the recording layer 135a according to the spin polarization direction of the electrons.

When the magnetization directions of the polarization layer 134 and the recording layer 135a are different, electrons are injected into the magnetic medium through the tip 131a. The injected electrons pass through the polarization layer 134 and are polarized in the polarization layer 134. The direction is spin polarized in accordance with the direction, and the magnetization direction of the bit of the recording layer 135a is changed in accordance with the spin polarization direction of the electrons so that information is recorded. When the polarization layers 134 and the recording layer 135a have the same magnetization directions, electrons are injected into the magnetic medium 135 through the substrate 135b. Among the injected electrons, electrons having the same spin direction as the polarization layer 134 pass through the recording layer 135a and the polarization layer 134, but electrons having different spin directions are returned to the recording layer 135a and returned to the recording layer 135a. Information is recorded by changing the magnetization direction of the bits of the recording layer 135a in accordance with the spin polarization direction of the electrons.

4B shows a magnetic medium according to a second embodiment of the present invention and an information recording apparatus according to a fourth embodiment of the present invention for recording information thereon.

In the magnetic medium according to the second embodiment of the present invention illustrated in FIG. 4B, unlike the magnetic medium according to the first embodiment of the present invention illustrated in FIG. 4A, the positions of the polarization layer 144 and the recording layer 145a are different from each other. Inverted. That is, the polarization layer 144 is laminated on the upper surface of the substrate 145b, and the recording layer 145a is positioned on the upper surface thereof. Due to this inversion structure, the direction of electron injection along the magnetization directions of the polarization layer 144 and the recording layer 145a is also reversed. The probe 141 for injecting electrons and the controller 147 for applying current to the probe 141 may use a conductive probe and a control circuit similar to the probe 131 and the controller 137 illustrated in FIG. 4A. Reference numeral 141a denotes a tip, and 141b denotes a cantilever supporting the tip 141a.

When the magnetization directions of the polarization layer 144 and the recording layer 145a are the same, electrons are injected through the tip 111a. The electrons having the same spin polarization direction as the polarization layer 144 among the injected electrons are the polarization layer 144. And electrons passing through the recording layer 145a but having different spin directions return from the polarization layer 144 to return to the recording layer 145a and change the magnetization direction of the recording layer 145a to record information. When the polarization layers 144 and the recording layer 145a have different magnetization directions, electrons are injected through the substrate 145b. The electrons passing through the substrate 145b are spin polarized while passing through the polarization layer 144 to change the magnetization direction of the bit contacted by the probe 111 to be the same as the spin polarization direction.

The information recording apparatus according to the third embodiment of the present invention includes conductive probes 131 and 141 for reproducing the magnetic medium according to the first and second embodiments of the present invention, and the polarization layers 134 and 144. The information is recorded on the magnetic medium 135, 145 by injecting electrons in different directions depending on the arrangement of the recording layers 135a, 145a.

According to the present invention, a light source, a probe, or a polarization layer that spin-polarizes electrons in one direction is provided, and information can be recorded at high speed by adjusting the magnetization direction of the magnetic recording layer.

While many details are set forth in the foregoing description, they should be construed as illustrative of preferred embodiments, rather than to limit the scope of the invention. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the technical spirit described in the claims.

As described above, the advantages of the magnetic medium having the polarization layer according to the present invention and the information recording apparatus and the recording method for recording the magnetic medium according to the present invention are high speed by changing the magnetization direction of the recording layer by spin polarizing electrons. This means that information can be recorded on magnetic media.

Claims (38)

A light source for emitting circularly polarized light; And And a probe for recording information by injecting electrons spin-polarized by the circularly polarized light into a magnetic medium to change the magnetization direction of the recording layer. The method of claim 1, And the light source is a laser. And a tip capped with a magnetic film that spin-polarizes electrons, and a probe for recording information by injecting the electrons into a magnetic medium to change the magnetization direction of the recording layer. A magnetic medium comprising a polarization layer for spin polarizing electrons and a recording layer whose magnetization direction is changed in accordance with the spin polarization direction of electrons spin-polarized by the polarization layer; And And a probe for moving the magnetic medium and recording the information. The method of claim 4, wherein And the probe injects electrons into the magnetic medium. The method of claim 4, wherein And the magnetic medium is injected with electrons by an external power source. The method of claim 4, wherein And the recording layer and the polarization layer have horizontal magnetic anisotropy or vertical magnetic anisotropy. The method of claim 4, wherein And the recording layer and the polarization layer are continuous thin film layers. The method of claim 4, wherein And the recording layer and the polarization layer are patterned in whole or in part in the thin film layer. The method of claim 4, wherein And the recording layer and the polarization layer are thin film layers made of nanoparticles. The method of claim 4, wherein And the recording layer and the polarization layer further comprise an oxide layer through which electrons tunnel at an interface. The method of claim 4, wherein And the polarization layer further comprises an oxide layer on the surface of which the electrons tunnel. The method of claim 4, wherein And the recording layer further comprises an oxide layer on the surface of which the electrons tunnel. The method of claim 4, wherein And the recording layer and the polarization layer further comprise a metal layer at an interface. A polarization layer for spin polarizing electrons; And And a recording layer whose magnetization direction changes in accordance with the spin polarization direction of the electrons. The method of claim 15, And the recording layer and the polarization layer have horizontal magnetic anisotropy or vertical magnetic anisotropy. The method of claim 15, And the recording layer and the polarization layer are continuous thin film layers. The method of claim 15, The recording layer and the polarization layer are magnetic media, characterized in that all or part of the thin film layer is patterned. The method of claim 15, And the recording layer and the polarization layer are thin film layers made of nanoparticles. The method of claim 15, And the recording layer and the polarization layer further comprise an oxide layer through which electrons tunnel at an interface. The method of claim 15, The polarization layer is a magnetic medium, characterized in that further comprising an oxide layer tunneling electrons on the surface. The method of claim 15, And the recording layer further comprises an oxide layer on the surface of which the electrons tunnel. The method of claim 15, And the recording layer and the polarization layer further include a metal layer at an interface. A first step of spin polarizing electrons injected into the probe; And And recording the information by changing the magnetization direction of the recording layer of the magnetic medium according to the spin polarization direction of the electrons. The method of claim 24, And spin-polarize electrons by irradiating the probe with circularly polarized light. The method of claim 25, And said circularly polarized light is a laser beam. The method of claim 24, And a tip capping a magnetic film for spin-polarizing electrons on the probe. A first step of providing a magnetic medium having a recording layer and a polarization layer, and a probe for moving information on the magnetic medium; And a second step of spin-polarizing the electrons by the polarization layer and then recording information by changing the magnetization direction of the recording layer according to the spin polarization direction of the electrons. The method of claim 28, And the electron is injected through the probe. The method of claim 28, And the electron is injected through a magnetic medium. The method of claim 28, And the recording layer and the polarization layer have horizontal magnetic anisotropy or vertical magnetic anisotropy. The method of claim 28, And the recording layer and the polarization layer are formed of a continuous thin film layer. The method of claim 28, And the recording layer and the polarization layer are formed by patterning all or part of the thin film layer. The method of claim 28, And the recording layer and the polarization layer are thin film layers made of nanoparticles. The method of claim 28, And the recording layer and the polarization layer further form an oxide layer through which electrons tunnel at an interface. The method of claim 28, And the polarization layer further forms an oxide layer through which electrons tunnel. The method of claim 28, And the recording layer further forms an oxide layer through which electrons tunnel. The method of claim 28, And the recording layer and the polarization layer further form a metal layer at an interface.