JP2017168514A - Magnetic element, method for manufacturing magnetic element, and magnetic memory device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide magnetic elements where a magnetic structure moving at high speed more stably than a conventional magnetic structure by current drive is formed.SOLUTION: A magnetic element includes a first magnetic layer and a second magnetic layer which are magnetized in a direction perpendicular to the surface and antiferromagnetic exchange coupled. In the first magnetic layer and the second magnetic layer, a pair of spiral magnetic structures whose directions of rotation are opposite when seen from the first magnetic layer side are formed. In the central part of the respective spiral magnetic structures and outside the spiral magnetic structures, directions of magnetic moments are anti-parallel. The pair of spiral magnetic structures are manufactured via a step in which to irradiate laser beam to a part of the first magnetic layer and perform local heating and a step in which to apply an external magnetic field in the opposite direction to a magnetization direction to the direction of the first magnetic layer and inverts the magnetic moment in the part of the first magnetic layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a magnetic element having a novel magnetic structure, a method for manufacturing the magnetic element, and a magnetic memory device including the magnetic element.

  Conventionally, from the viewpoint of reducing power consumption, development of a non-volatile memory that does not require power to hold stored data has been underway. As a nonvolatile memory, a magnetic element such as an MRAM (Magnetic Random Access Memory) that uses the direction of a magnetic moment (the magnetization direction of a magnetic material) for data storage is known. The magnetic element (magnetoresistance effect element) used in the MRAM includes a magnetic layer (fixed layer) in which the direction of the magnetic moment is fixed with a spacer layer in between, and a magnetic layer (free layer) in which the direction of the magnetic moment is changed by an external magnetic field And is configured to read and write data using the property that the electric resistance of the magnetoresistive element changes according to the direction of the magnetic moment of the free layer.

  On the other hand, studies have been conducted to read / write data by driving a magnetic structure formed in a magnetic element. For example, Non-Patent Document 1 discloses that data is driven by current by driving a boundary (domain wall) of a patterned magnetic domain formed on an elongated wire-shaped magnetic body (magnetic nanowire), which is called a racetrack memory. Memory is listed. In the domain wall motion type memory, the density of stored data is expected to be increased by sufficiently reducing the domain wall size.

  Here, as a magnetic structure formed in a magnetic element, a magnetic bubble which is a cylindrical magnetic domain formed in a perpendicular magnetization film is known. The perpendicular magnetization film is a ferromagnetic thin film having uniaxial anisotropy, and has an easy axis of magnetization oriented in a direction perpendicular to the film surface (perpendicular direction). A magnetic bubble is formed when a magnetic field is applied in a direction perpendicular to the plane and opposite to the magnetization direction of the perpendicular magnetization film.

  Since a magnetic bubble has a higher moving speed than a normal domain wall formed in a magnetic material, a magnetic bubble memory using a magnetic bubble is expected to operate with lower power consumption than a normal domain wall moving memory. Yes.

Parkin, et al., Magnetic Domain-Wall Racetrack Memory, Science, 320, 190 (11 April 2008), doi: 10.1126 / science.1145799

  However, there is a concern that when the magnetic bubble is driven by current, its movement stability is low, and the operation of the magnetic bubble memory becomes unstable or does not operate.

  A first object of the present invention is to provide a magnetic element in which a magnetic structure that moves more stably and at a higher speed than a conventional magnetic structure is formed by current driving.

  A second object of the present invention is to provide a nonvolatile memory that operates stably with lower power consumption than the prior art.

In the first aspect of the present invention,
A first magnetic layer and a second magnetic layer magnetized in a direction perpendicular to the plane and antiferromagnetic exchange coupled;
The first magnetic layer and the second magnetic layer are formed with a pair of spiral magnetic structures whose rotational directions are opposite to each other when viewed from the first magnetic layer side,
The direction of the magnetic moment is antiparallel between the center of each vortex magnetic structure and the outside of the vortex magnetic structure.
A magnetic element is provided.

In the second aspect of the present invention,
Providing a laminate comprising a first magnetic layer and a second magnetic layer magnetized in a perpendicular direction and antiferromagnetic exchange coupled;
Irradiating a part of the first magnetic layer with a laser beam to perform local heating;
Applying an external magnetic field in a direction opposite to the magnetization direction of the first magnetic layer, and reversing the magnetic moment in a part of the first magnetic layer,
A method for manufacturing a magnetic element is provided.

In the third aspect of the present invention,
A magnetic element;
A writing unit for writing data to the magnetic element;
A reading unit for reading data written in the magnetic element,
The magnetic element has a first magnetic layer and a second magnetic layer that are magnetized in a perpendicular direction and are antiferromagnetic exchange coupled,
The writing unit is configured to form a pair of spiral magnetic structures whose rotation directions are opposite to each other when viewed from the first magnetic layer side in the first magnetic layer and the second magnetic layer,
The reading unit is configured to read whether or not the pair of spiral magnetic structures exists in the magnetic element as 1-bit data,
The direction of the magnetic moment is antiparallel between the center of each vortex magnetic structure and the outside of the vortex magnetic structure.
A magnetic memory device is provided.

According to a first aspect of the invention,
By current driving, it is possible to obtain a magnetic element having a pair of vortex magnetic structures that move more stably and at a higher speed than conventional magnetic structures.

According to a second aspect of the invention,
By current driving, it is possible to easily obtain a magnetic element having a pair of vortex magnetic structures that move more stably and at a higher speed than conventional magnetic structures.

According to a third aspect of the invention,
A non-volatile memory device that operates stably with lower power consumption than that of the prior art is obtained by forming a pair of spiral magnetic structures that move more stably and at a higher speed than conventional magnetic structures in the magnetic element. Can do.

It is a perspective view which shows the magnetic element which concerns on Embodiment 1 of this invention. It is a figure which shows the magnetic structure formed in the 1st magnetic layer. It is a figure which shows the magnetic structure formed in the 2nd magnetic layer. It is a figure which shows the preparatory step included in the method of manufacturing the magnetic element which concerns on Embodiment 1 of this invention. It is a figure which shows the laser irradiation step included in the method of manufacturing the magnetic element which concerns on Embodiment 1 of this invention. It is a figure which shows the magnetic field application step included in the method of manufacturing the magnetic element which concerns on Embodiment 1 of this invention. It is a figure which shows the behavior of the magnetic moment after the magnetic field application step in a magnetic element. It is a figure which shows the behavior of the magnetic moment after the magnetic field application step in a magnetic element. It is the graph which compared the speed when the magnetic structure formed in the magnetic element of an Example and the magnetic element of a comparative example each was current-driven by simulation. It is the graph which plotted the speed | velocity | rate when carrying out the electric current drive of the vortex-like magnetic structure pair formed in the magnetic element of an Example with respect to the current density of a drive current. It is a figure which shows the behavior when the magnetic bubble formed on the magnetic element of the comparative example 1 is current-driven by simulation. It is the photograph which image | photographed the magnetic bubble formed on the TbFeCo layer with the polar Kerr effect microscope. It is the photograph which image | photographed the behavior when the magnetic bubble formed on the TbFeCo layer was current-driven with the polar Kerr effect microscope. It is a figure which shows a behavior when the vortex magnetic structure pair formed in the magnetic element of an Example is current-driven by simulation. It is a figure which shows the magnetic memory device based on Embodiment 2 of this invention. It is a figure which shows the read-out part of the magnetic memory device based on Embodiment 2 of this invention. It is a figure which shows reading of the data in the magnetic memory apparatus based on Embodiment 2 of this invention. It is a figure which shows the modification of the read-out part of the magnetic memory device based on Embodiment 2 of this invention. It is a figure which shows writing of the data in the magnetic memory device based on Embodiment 2 of this invention. It is a figure which shows transfer of the data in the magnetic memory apparatus based on Embodiment 2 of this invention. It is a figure which shows the magnetic memory device based on Embodiment 3 of this invention. It is a figure which shows the drive part for data transfers of the magnetic memory apparatus which concerns on Embodiment 3 of this invention. It is a figure which shows the modification of the data transfer drive part of the magnetic memory apparatus which concerns on Embodiment 3 of this invention. It is a figure which shows the modification of the data transfer drive part of the magnetic memory apparatus which concerns on Embodiment 3 of this invention. It is a figure which shows the modification of the data transfer drive part of the magnetic memory apparatus which concerns on Embodiment 3 of this invention. It is a figure which shows the modification of the data transfer drive part of the magnetic memory apparatus which concerns on Embodiment 3 of this invention. It is a figure which shows the modification of the data transfer drive part of the magnetic memory apparatus which concerns on Embodiment 3 of this invention. It is a figure which shows the modification of the data transfer drive part of the magnetic memory apparatus which concerns on Embodiment 3 of this invention.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. In the following description, terms indicating a specific direction (“up”, “down”, etc.) are used as necessary, but these are used to facilitate understanding of the present invention. It should not be understood that it is used for the purpose of limiting the scope. For convenience of explanation, the Z direction described in the drawings is referred to as the up-down direction, the + Z direction is the upward direction, and the −Z direction is the downward direction. Further, the X direction and the Y direction described in the drawings are directions perpendicular to each other and perpendicular to the Z direction.

[Embodiment 1]
(Configuration of magnetic element 1)
As shown in FIG. 1, the magnetic element 1 includes a first magnetic layer 10, a second magnetic layer 20, and a nonmagnetic layer 30 provided between the first magnetic layer 10 and the second magnetic layer 20. . The first magnetic layer 10 and the second magnetic layer 20 are ferromagnetic thin films having uniaxial anisotropy, and are perpendicular magnetization films having easy axes of magnetization oriented in a direction perpendicular to the film surface. The first magnetic layer 10 and the second magnetic layer 20 preferably have the same thickness. The magnetic element 1 is provided on an insulating substrate, for example.

  Examples of the ferromagnetic material constituting the first magnetic layer 10 and the second magnetic layer 20 are TbFeCo (terbium iron cobalt), CoFeB (cobalt iron boron), CoPt (cobalt platinum), CoCrPt (cobalt chromium platinum), CoFeSi ( It is an alloy such as cobalt iron silicon) or MnSi (silicomanganese). A material that has a Curie temperature higher than an ambient temperature (for example, room temperature) is used for the ferromagnetic material constituting the first magnetic layer 10 and the second magnetic layer 20. The Curie temperature is preferably high enough not to exceed the temperature of the first magnetic layer 10 and the second magnetic layer 20 due to Joule heat generated when a current is passed through the magnetic element 1. Since the perpendicular magnetization film can be easily formed by distorting the lattice structure of the ferromagnetic thin film, many ferromagnetic materials can be used as materials constituting the first magnetic layer 10 and the second magnetic layer 20 in addition to the exemplified materials. Can be used.

  Here, in general, when two ferromagnetic layers are provided with a nonmagnetic layer interposed therebetween, the coupling strength of the two ferromagnetic layers changes according to the thickness of the nonmagnetic layer (for example, SSPParkin, Phys Rev. Lett 67, 3598 (1991)). The two ferromagnetic layers are ferromagnetic exchange coupled or antiferromagnetic exchange coupled depending on the thickness of the nonmagnetic layer. In the case of ferromagnetic exchange coupling, the magnetic moments of the two ferromagnetic layers are directed in the same direction, and in the case of antiferromagnetic exchange coupling, the magnetic moments of the two ferromagnetic layers are directed in opposite directions.

  The nonmagnetic layer 30 has a thickness at which the first magnetic layer 10 and the second magnetic layer 20 are antiferromagnetic exchange coupled. The thickness of the nonmagnetic layer 30 is, for example, about 2 nm or less. The nonmagnetic or paramagnetic material constituting the nonmagnetic layer 30 is preferably a metal having a large spin orbit interaction, such as platinum (Pt), ruthenium (Ru), rhodium (Rh).

  The first magnetic layer 10 is magnetized in a downward direction (−Z direction) in a direction perpendicular to the film surface (hereinafter referred to as a perpendicular direction) except for a spiral magnetic structure 11 described later. . The second magnetic layer 20 is magnetized in the upward direction (+ Z direction) in the perpendicular direction except for a portion of a spiral magnetic structure 21 described later.

  The magnetization directions of the first magnetic layer 10 and the second magnetic layer 20 may be opposite to those described. That is, the first magnetic layer 10 is magnetized in the upward direction (+ Z direction) in the perpendicular direction except for a portion of a spiral magnetic structure 11 described later, and the second magnetic layer 20 is formed of a spiral magnetic structure 21 described later. Except for the portion, it may be magnetized in the downward direction (−Z direction) in the perpendicular direction. At this time, the magnetization directions in the spiral magnetic structures 11 and 21 are also reversed upside down.

  A spiral magnetic structure 11 is formed in the first magnetic layer 10. As shown in FIGS. 1 and 2, in the spiral magnetic structure 11, magnetic moments 12 of a plurality of atoms (hereinafter referred to as atomic groups) located in the central portion (core) are directed upward (+ Z direction). . As described above, the magnetic moment 13 outside the spiral magnetic structure 11 is directed downward. Thus, the direction of the magnetic moment is antiparallel between the central portion of the vortex magnetic structure 11 and the outside of the vortex magnetic structure 11.

  In the present embodiment, the magnetic moment 14 between the atomic group located at the center of the spiral magnetic structure 11 and the external magnetic moment 13 has an in-plane component. Further, the magnetic moment 14 collapses while spiraling from the outside of the spiral magnetic structure 11 toward the central portion, and the upward perpendicular component increases gradually. However, the direction of the magnetic moment 14 is not limited to this.

  A spiral magnetic structure 21 is formed in the second magnetic layer 20. As shown in FIGS. 1 and 3, in the spiral magnetic structure 21, the magnetic moment 22 at the center (core) is directed downward (−Z direction). As described above, the magnetic moment 23 outside the spiral magnetic structure 21 is directed upward. Thus, the direction of the magnetic moment is antiparallel between the central portion of the vortex magnetic structure 21 and the outside of the vortex magnetic structure 21.

  In the present embodiment, the magnetic moment 24 between the atomic group located at the center of the spiral magnetic structure 21 and the atomic group located outside has an in-plane component. Further, the magnetic moment 24 gradually falls down while vortexing from the outside of the spiral magnetic structure 21 toward the central portion, and the downward perpendicular surface component gradually increases. However, the direction of the magnetic moment 24 is not limited to this.

  A pair of spiral magnetic structures (hereinafter referred to as spiral magnetic structure pairs) 11 and 21 formed in the first magnetic layer 10 and the second magnetic layer 20 are viewed from the first magnetic layer 10 side (or the second magnetic layer). The directions of rotation are opposite to each other (seen from the 20 side).

  The vortex magnetic structure pairs 11 and 21 are formed continuously in the thickness direction (Z direction) of the first magnetic layer 10 and the second magnetic layer 20, and are cylindrical or columnar magnetic domain structures like magnetic bubbles. (Or a domain wall). For example, the diameter of the circular circle of the cylinder or the column constituting the pair of spiral magnetic structures 11 and 21 may be about 10 nm or more and about 300 nm or less. By reducing the diameter, for example, it is possible to increase the degree of integration of the magnetic memory described in the second embodiment. Of the vortex magnetic structure 11 (vortex magnetic structure 21), the diameter of the circle on the upper surface of the first magnetic layer 10 (second magnetic layer 20) and the diameter of the circle on the lower surface of the first magnetic layer 10 (second magnetic layer 10). It may vary depending on the thickness and material of the magnetic layer 20) and the thickness and material of the nonmagnetic layer 30.

  The arrows shown in FIGS. 2 and 3 do not indicate the magnetic moment of one atom, but indicate the magnetic moment of an atomic group. Therefore, the expression “magnetic moment in a region” in this specification means the magnetic moment of an atomic group included in the region. 2 and 3, for the convenience of explanation, the inside of the alternate long and short dash line is defined as the spiral magnetic structure 11. For example, a region where the magnetic moment has substantially no in-plane component is indicated as “vortex magnetic structure”. Can be defined as "outside of structure 11".

  The pair of vortex magnetic structures 11 and 21 formed in the magnetic element 1 is a novel magnetic structure, and can move stably and at high speed by current driving as compared with conventional magnetic structures (such as magnetic bubbles) and The threshold for movement by driving is also small. This effect will be confirmed by a simulation described later. The spiral magnetic structure pairs 11 and 21 are stable not only when a current flows through the magnetic element 1 but also when a current does not flow through the magnetic element 1.

(Method of manufacturing magnetic element 1)
Next, a method for manufacturing the magnetic element 1 will be described with reference to FIGS. In FIGS. 5 to 8, the range in which the magnetic moment is downward is shown in white, the range in which the magnetic moment is upward is hatched, and the range in which the magnetic moment has an in-plane component is dotted. Although the said method is not limited to this, For example, it implements under atmospheric pressure and room temperature.

  The method includes a step 101 of preparing a laminate 40 including a first magnetic layer 10, a second magnetic layer 20, and a nonmagnetic layer 30 (see FIG. 4). The laminated body 40 is provided by laminating the second magnetic layer 20, the nonmagnetic layer 30, and the first magnetic layer 10 on an insulating substrate by a method such as vapor deposition.

  The method includes a step 102 of irradiating a laser beam 50 to a partial region 15 (inside the dotted line in FIG. 5) in the plane of the first magnetic layer 10. By the laser irradiation step 102, the temperature of the atomic group included in the region 15 increases. The irradiation range (or beam diameter) of the laser beam 50 corresponds to the size of the spiral magnetic structure 11 formed in the first magnetic layer 10. The irradiation parameters of the laser beam 50 (the wavelength of the laser beam, the irradiation time, etc.) are the target temperatures at which the atomic group located in the region 15 is higher than the Curie temperature, which is the transition temperature from the ferromagnetic material to the paramagnetic material. Is set to be In the case of TbFeCo having a Curie temperature of about 140 degrees, the target temperature is set to 150 degrees, for example. At this time, the lower the Curie temperature of the ferromagnetic material constituting the first magnetic layer 10 and the second magnetic layer 20, the lower the target temperature, and thus the lower the energy of the laser beam 50 to be irradiated. In the region 15, the saturation magnetization decreases as the temperature of the atomic group rises, and the magnetic moment can be controlled with an external magnetic field smaller than those in the other regions 16.

  The method includes a step 103 of applying an external magnetic field 60 in the opposite direction (upward direction, + Z direction) to the magnetization direction (downward direction, -Z direction) of the first magnetic layer 10 (see FIG. 6). The magnitude of the external magnetic field 60 is so large that the magnetic moment in the region 15 where the temperature is rising is reversed, and so small that the magnetic moment in the other region 16 is not reversed. Due to the magnetic field application step 103, the magnetic moment in the region 15 is reversed in the same upward direction as that of the external magnetic field 60, and the magnetic moments in the other regions 16 remain in the downward direction opposite to the external magnetic field 60. Further, the magnetic moment in the region 17 outside the region 15 is inclined so as to have an in-plane component (sleeps in the plane). The timing at which the external magnetic field 60 starts to be applied may be before step 102 in which the laser beam 50 is irradiated. The magnetic field application step 103 is completed in about 10 nanoseconds or less, for example.

  As shown in FIG. 7, after the magnetic field applying step 103, the range of the region 17 where the magnetic moment has an in-plane component is expanded. This is because, after the magnetic field application step 103, the magnetic moment in the region 17 is antiferromagnetically exchanged with the magnetic moment in the second magnetic layer 20 and transitions to a stable state. At the same time, the magnetic moment in the region 27 corresponding to the region 17 in the second magnetic layer 20 has an in-plane component.

  As shown in FIG. 8, after the state shown in FIG. 7, the magnetic moment in the region 25 in the region 27 of the second magnetic layer 20 corresponding to the region 15 of the first magnetic layer 10 is reversed downward. . This is because the unstable magnetic structure formed in the second magnetic layer 20 tends to stabilize with respect to the magnetic structure already stable in the first magnetic layer 10 in the state of FIG. In this way, the vortex magnetic structure 11 is formed in the first magnetic layer 10, and the vortex magnetic structure is seen in the second magnetic layer 20 when viewed from the first magnetic layer 10 side (or viewed from the second magnetic layer 20 side). Thus, a spiral magnetic structure 21 is formed in the direction opposite to that in FIG. The magnetic moments in the central regions 15 and 25 are antiparallel to the magnetic moments in the external regions 16 and 26, respectively. The magnetic moment in the regions 15 and 16 of the first magnetic layer 10 is antiparallel to the magnetic moment in the regions 25 and 26 of the second magnetic layer.

  The time from the start of step 103 to the formation of the spiral magnetic structure pairs 11 and 21 depends on the magnitude of the applied external magnetic field, but can be, for example, about 2 nanoseconds or less. As described above, the laser irradiation step 102 and the magnetic field application step 103 can quickly and easily obtain the magnetic element 1 in which the spiral magnetic structure pair is formed.

(simulation)
Next, in order to confirm the effect of the magnetic element 1 according to the first embodiment, the first magnetic layer 10 and the second magnetic layer 20 are separated by small cells, and for each cell, the motion of the magnetic moment represented by the following formula (1) A micromagnetic simulation was performed to solve the equation (Landau-Lifschitz-Gilbert equation).

  As an example of the magnetic element 1, a magnetic thin wire having a stripe shape was used. The first magnetic layer 10 and the second magnetic layer 20 were made of TbFeCo having a thickness of 5 nm, and a nonmagnetic layer 30 having a thickness of 0 nm was further introduced. In other words, the distance between the first magnetic layer 10 and the second magnetic layer 20 is set to 0, and the material parameter of the nonmagnetic layer 30 is not taken in, and the exchange between the first magnetic layer 10 and the second magnetic layer 20 is performed. Energy was taken as a parameter. The cell size was 10 nm long × 10 nm wide × 5 nm thick.

In the formula (1), m is a magnetization vector. Γ is the gyromagnetic ratio of electrons, and its magnitude is 1.76 · 10 ⁷ rad / (s · Oe).

In the formula (1), H _eff is an effective magnetic field received by the magnetic moment, and is the sum of the magnetic field created by the magnetization of each cell and the anisotropic magnetic field. The anisotropic magnetic field is obtained from the exchange energy between the nearest cells, the exchange field obtained from the exchange energy between the first magnetic layer 10 and the second magnetic layer 20, and the magnetic anisotropy energy of perpendicular magnetization ( Japanese journal of applied physics vol.28, No.12, December, 1989, pp. 2485-2507 (see formulas (2) to (4)).

The exchange energy between the nearest cells is calculated using the exchange stiffness constant A. The size of the exchange stiffness constant A, was 1.0 × 10- ⁷ erg / cm. A first magnetic layer 10 exchange energy between the second magnetic layer 20 is ^{-A (= - 1.0 × 10- 7} erg / cm) it was. The magnitude of the perpendicular magnetic anisotropy energy Ku was 1.0 × 10 ⁶ erg / cm ³ .

In the formula (1), M _S is the magnitude of saturation magnetization, and α is a damping constant. As values obtained from experiments on a thin film of TbFeCo, the damping constant α was set to 0.4, and the value of the saturation magnetization M _S was set to 400 emu / cm ³ .

FIG. 9 is a graph comparing the moving speed when the magnetic structures respectively formed in the magnetic element of the example and the magnetic element of the comparative example are current-driven by simulation. The horizontal axis of the graph represents time (ns), and the vertical axis represents the displacement (nm) of each magnetic structure. The magnitude of the drive current density J was set to 1.0 × 10 ¹² (A / m ² ). The solid line in the graph shows the results for the pair of spiral magnetic structures 11 and 21 formed in the magnetic element of the example, the broken line shows the result for the magnetic bubbles formed in the magnetic element of Comparative Example 1, and the dotted line indicates The result about the normal domain wall formed in the magnetic element of the comparative example 2 is shown. The magnetic elements of Comparative Examples 1 and 2 are fine magnetic wires having a magnetic element stripe shape, like the magnetic elements of the examples.

  The magnetic element of Comparative Example 1 includes a single layer perpendicular magnetization film of TbFeCo. Magnetic bubbles are formed in the magnetic element. This magnetic bubble can be formed by irradiating a partial region in the plane of the TbFeCo layer with laser light. In Comparative Example 1, the same values as in the example were used for the simulation parameters.

  The magnetic element of Comparative Example 2 includes a single-layer perpendicular magnetization film of TbFeCo. In the magnetic element, a plurality of magnetic domains having different magnetization directions are formed. The plurality of magnetic domains are generated by generating a current magnetic field in the TbFeCo layer using a recording head arranged close to a magnetic sensor having a tunnel magnetoresistive effect element, or on a straight line so as to cross the TbFeCo layer. It can be formed by irradiation. In Comparative Example 2, the same values as in the example were used for the simulation parameters.

  For the pair of spiral magnetic structures formed in the magnetic element of the example, the magnetic bubbles formed in the magnetic element of Comparative Example 1, and the normal domain wall formed in the magnetic element of Comparative Example 2, the average moving speed (displacement amount ( nm) / 4 ns) were 70 m / s, 44 m / s and 20 m / s, respectively.

  From the result of the average moving speed, it can be seen that the vortex magnetic structure pairs 11 and 21 move at a higher speed than the magnetic bubbles and normal domain walls by current driving. The solid line (vortex magnetic structure) has higher linearity or is closer to a straight line than the broken line (magnetic bubble) and the dotted line (domain wall). Therefore, it can be seen that the spiral magnetic structure pairs 11 and 21 move at a more constant speed than the magnetic bubbles and the magnetic domains.

FIG. 10 is a graph plotting the speed when the current drive of the pair of vortex magnetic structures 11 and 21 formed in the magnetic element of the example is performed with respect to the current density of the drive current. The horizontal axis of the graph indicates the logarithmically displayed current density J (A / m ² ), and the vertical axis indicates the logarithmically displayed moving speed v (m / s). As shown in the graph, the moving speed is roughly proportional to the current density. The proportionality constant is about 70 × 10 ⁻¹² .

It is known that there is a threshold current of about 10 ¹⁰ A / m ² in the drive current of the magnetic bubble and the normal domain wall, and it does not move at a current smaller than the threshold current. For example, the literature (Li et al., Current-Induced Domain Wall Motion in TbFeCo Wires With Perpendicular Magnetic Anisotropy, IEEE Transactions on Magnetics, Vol. 46, NO. 6, June 2010) The threshold current when the domain wall is driven by current is examined (see FIG. 4). FIG. 4 shows that the smaller the film thickness, the larger the threshold current, 4.5 × 10 ¹⁰ A / m ² when the film thickness is 50 nm, and 5.5 when the film thickness is 30 nm. It is shown to be 8 × 10 ¹⁰ A / m ² .

On the other hand, as can be seen from FIG. 10, in the spiral magnetic structure pair formed in the magnetic element of the example, the corresponding threshold current is smaller than 10 ⁶ A / m ² . In this way, the spiral magnetic structure pair can be driven even with a small current density.

  FIG. 11 is a diagram illustrating the behavior when a magnetic bubble formed on the magnetic element of Comparative Example 1 is current-driven by simulation. FIG. 11 is a view of the magnetic bubble as viewed from above, and the magnetic bubble is shown in black. As shown in (a), the magnetic bubble that was initially substantially circular is deformed so as to extend in the direction of current flow as time passes, as shown in (b) and (c). The greater the current density, the greater the deformation. Thus, the shape of the magnetic bubble is not stable with respect to current drive.

  Experiments have confirmed that the shape of the magnetic bubbles is not stable with respect to current drive. FIG. 12 is a photograph of a magnetic bubble formed on the same TbFeCo layer as in Comparative Example 2 taken with a polar Kerr effect microscope, and FIG. 13 shows the behavior of the magnetic bubble when it is driven by current with the polar Kerr effect microscope. It is a photograph taken by As shown in FIG. 13, the magnetic bubble that was initially circular as shown in FIG. 13A is a current flow direction as time passes, as shown in FIGS. 13B and 13C. It is deformed to stretch.

  FIG. 14 is a diagram illustrating a behavior when a vortex magnetic structure pair formed in the magnetic element of the example is current-driven by simulation. FIG. 14 is a top view of the vortex magnetic structure pair, and the vortex magnetic structure pair is shown in black. As shown in (b), (c), (d), and (e), the spiral magnetic structure pair that was initially substantially circular as shown in (a) maintains almost the same shape as time passes. ing. Thus, the shape of the spiral magnetic structure is stable with respect to current drive.

  Here, the stability of the magnetic structure formed in the magnetic element and the moving speed by current drive vary according to the values of the parameters used in the simulation. A person skilled in the art can achieve a desired stability and moving speed by adjusting the material constituting one or more magnetic layers provided in the magnetic element, the thickness of the one or more magnetic layers, and the like. . For example, the saturation magnetization Ms, the exchange stiffness constant A, and the magnetic anisotropy energy Ku of perpendicular magnetization can be changed by changing the composition of the alloy constituting the magnetic layer (for example, IEEE TRANSACTIONS ON MAGNETICS, VOL. 41, NO. 10, OCTOBER 2005, Table 1 describes the relationship between the ratio of Tb contained in TbFeCo and the saturation magnetization Ms, exchange stiffness constant A, and magnetic anisotropy energy Ku of perpendicular magnetization) .

  As a result of the simulation, the advantages of the vortex magnetic structure pairs 11 and 21 over the conventional magnetic structure (such as magnetic bubbles) are stable and high-speed movement by current driving, and the threshold of movement by current driving is also small. It was confirmed. Accordingly, the magnetic element 1 according to the first embodiment, in which the spiral magnetic structure pairs 11 and 21 having such advantages are formed, is not limited to the magnetic memory device described in the second embodiment. There is a possibility that the generator is also suitably used.

[Embodiment 2]
FIG. 15 is a perspective view showing a magnetic memory device 200 according to Embodiment 2 of the present invention.
The magnetic memory device 200 includes a magnetic element (or magnetic memory element) 210 having a data transfer line 220 and a data write line 230. FIG. 15 shows the magnetic element 210 in which data has already been written. The magnetic element 210 corresponds to the laminated body 40 described in the first embodiment, that is, the magnetic element 1 in which the spiral magnetic structure pair is not formed. As shown in FIG. 16 and the like, the data transfer line 220 of the magnetic element 210 is provided between the first magnetic layer 225, the second magnetic layer 226, and between the first magnetic layer 225 and the second magnetic layer 226. A nonmagnetic layer 227 is provided. Corresponding to these layers 225, 226, and 227, the data write line 230 of the magnetic element 210 includes a first magnetic layer 234, a second magnetic layer 235, and a first magnetic layer 234 and a second magnetic layer, respectively. 235 and a nonmagnetic layer 236 provided therebetween. The magnetic element 210 is formed by vapor deposition of each layer in the stacked body 40 and photolithography.

  The data transfer line 220 is a magnetic thin line having a stripe shape, and extends in the X direction in FIG. The X direction shown in FIG. 15 is the longitudinal direction of the data transfer line 220. Reference numeral 241 denotes a spiral magnetic structure pair formed on the data transfer line 220. The data transfer line 220 is divided into a plurality of data areas 221 and 222. In the state where data as shown in FIG. 15 is written in the magnetic element 210, the vortex magnetic structure pair 241 is formed in the data area 221, and the vortex magnetic structure pair 241 is not formed in the data area 222. The data areas 221 and 222 are provided at regular intervals. As will be described later, one data area corresponds to 1-bit data. In the data transfer line 220, a data passage region 223 is provided at the tip of the magnetoresistive sensor 270 described later (on the right side of the magnetoresistive sensor 270 in FIG. 15).

  In the data transfer line 220, the entire end surfaces of the first magnetic layer 225, the second magnetic layer 226, and the nonmagnetic layer 227 are connected to the data transfer power supply 224 through lead wires. However, in the first embodiment, since the first magnetic layer 225, the second magnetic layer 226, and the nonmagnetic layer 227 are all made of metal, the first magnetic layer 225, the second magnetic layer 226, and the nonmagnetic layer 227 If at least one of them is connected to the data transfer power supply 224, all layers of the data transfer line 220 can be energized. The data transfer power supply 224 functions as a data transfer drive unit that applies a voltage between both ends of the data transfer line 220, drives the vortex magnetic structure pair 241 with current, and moves on the data transfer line 220. The data transfer power supply 224 is configured to reverse the direction of the current flowing through the magnetic element 210.

  The data write line 230 is provided so as to intersect (or orthogonally intersect) the data transfer line 220, and extends in the Y direction in FIG. The Y direction shown in FIG. 15 is the longitudinal direction of data write line 230. As shown in FIG. 16, the first magnetic layer 234, the second magnetic layer 235, and the nonmagnetic layer 236 of the data write line 230 are the same as the first magnetic layer 225, the second magnetic layer 226, and the nonmagnetic layer of the data transfer line 220. Crosses with layer 227 respectively. Reference numeral 242 denotes a spiral magnetic structure pair formed on the data write line 230. In the data write line 230, the entire end surfaces of the first magnetic layer 234, the second magnetic layer 235, and the nonmagnetic layer 236 are connected to the data write power supply 233 via lead wires. The data write power supply 233 functions as a data write drive unit that applies a voltage between both ends of the data write line 230, drives the vortex magnetic structure pair 242 with current, and moves on the data write line 230. To do.

As described above, the spiral magnetic structure pair 242 can be driven at a low current density of about 10 ¹⁰ A / m ² or less, which cannot drive a magnetic bubble or the like. For example, the data transfer power source 224 and the data write power source 233 pass a current at a current density of about 10 ⁶ A / m ² or more and about 10 ¹⁰ A / m ² or less. Thereby, the moving speed can be ensured while the vortex magnetic structure pair 242 is driven with a small current density.

  A data generation region 231 where the vortex magnetic structure pair 242 is generated is located at one end side of the data write line 230, and data from which the vortex magnetic structure pair 242 is erased is located at the other end side of the data write line 230. An erase area 232 is located.

  The magnetic memory device 200 further includes a laser light source 250 and a magnetic field generator 260 provided in the data generation region 231 of the data write line 230. The laser light source 250 is used in the laser irradiation step 102 described with reference to FIG. 5, and locally heats the region 15 in the plane of the first magnetic layer 10 included in the stacked body 40 by irradiation with laser light. The magnetic field generator 260 is used in the magnetic field application step 103 described with reference to FIG. 6 and applies an external magnetic field to the stacked body 40. As described above, the laser light source 250 and the magnetic field generation unit 260 function as a writing unit for writing data to the data transfer line 220.

The magnetic memory device 200 further includes a magnetoresistive sensor 270 provided in a data region that is an intersection of the data transfer line 220 and the data write line 230. The magnetoresistive sensor 270 is a magnetic sensor using a TMR (tunnel magnetoresistive effect) element 271. As shown in FIG. 16, the TMR element 271 includes a pinned layer (fixed layer) 272 and a free layer 273 made of a ferromagnetic material, and a nonmagnetic insulating layer provided between the pinned layer 272 and the free layer 273. And a tunnel insulating film 274 which is a body thin film. The free layer 273 is configured by an intersection region between the first magnetic layer 225 of the data transfer line 220 and the first magnetic layer 234 of the data write line 230. Therefore, the free layer 273 is made of the same material as the first magnetic layers 225 and 234. The pinned layer 272 may be made of the same material as the free layer 273. The tunnel insulating film 274 may be made of a known material such as Al ₂ O ₃ (aluminum oxide) or MgO (magnesium oxide).

  The pin layer 272 and the free layer 273 of the TMR element 271 are provided with electrodes (not shown). The TMR element 271 is connected to a known readout circuit through this electrode. In the magnetoresistive sensor 270, the change in magnetization due to the movement of the spiral magnetic structure pair 241 over the data transfer line 220 is read as a change in the electrical resistance of the TMR element 271. Specifically, 1-bit data such as “1” (FIG. 17) when the spiral magnetic structure pair 241 exists on the data transfer line 220 and “0” when it does not exist (FIG. 16). Is read out. As described above, the magnetoresistive sensor 270 functions as a reading unit for reading data written in the data transfer line 220.

  In the second embodiment, the magnetoresistive sensor 270 may be another magnetoresistive sensor such as a magnetic sensor using an AMR (anisotropic magnetoresistive effect) element.

  In the second embodiment, as shown in FIG. 18, the TMR element 271 of the magnetoresistive sensor 270 has all the layers 272, 273, 274 above the intersection region of the data transfer line 220 and the data write line 230. May be provided. However, in the structure shown in FIGS. 16 and 17, the first magnetic layer 225 of the data transfer line 220 and the first magnetic layer 234 of the data write line 230 also serve as the free layer 273 of the magnetoresistive sensor 270. The manufacturing efficiency is improved as compared with the structure shown in FIG. Further, the TMR element 271 does not need to be provided in the intersection region between the data transfer line 220 and the data write line 230, and may be provided at any position on the data transfer line 220.

  In the second embodiment, instead of the magnetoresistive sensor 270 having the TMR element 271, for example, a hall sensor having a hall element (hole bar or the like) may be used as the reading unit. However, the use of the magnetoresistive sensor 270 is advantageous because it has higher sensitivity and higher response speed than the Hall sensor.

  Next, the operation of the magnetic memory device 200 will be described with reference to FIGS. 15, 19, and 20.

  When data is written to the data transfer line 220, a vortex magnetic structure pair 242 is generated in the data generation region 231 of the data write line 230 by the method described with reference to FIGS. 5 to 8 (see FIG. 15). The generated pair of vortex magnetic structures 242 is driven in the longitudinal direction (in the −Y direction) by driving the data write power source 233 until it reaches the data transfer line 220 over the data write line 230 as shown in FIG. )Moving. Thereby, the writing of the data 220 to the data transfer line is completed. Since the vortex magnetic structure pair 242 is stable even when no current is applied, the written data is not erased even if the current drive is stopped (that is, it is nonvolatile).

  When data written to the data transfer line 220 is read, the data transfer power supply 224 is driven. As a result, a magnetic field is generated in a direction in which the spiral magnetic structure pairs 241 and 242 are moved in the longitudinal direction (+ X direction) on the data transfer line 220. The pair of spiral magnetic structures 241 and 242 moving on the data transfer line 220 is detected as a change in electrical resistance of the TMR element 271 of the magnetoresistive sensor 270. The pair of spiral magnetic structures 241 and 242 moved to the tip of the magnetoresistive sensor 270 enters the data passage area 223. When reading the spiral magnetic structure pairs 241 and 242 that have entered the data passage area 223, the direction of the current by the data transfer power supply 224 is reversed to reverse the direction of the arrow shown in FIG. 20 (in the −X direction in FIG. 15). ) Move the pair of spiral magnetic structures 241 and 242 and are detected by the magnetoresistive sensor 270.

  When erasing data written in the data transfer line 220, by driving the data transfer power supply 224, the spiral magnetic structure pairs 241 and 242 move on the data transfer line 220 and intersect with the data write line 230. To reach. In this state, the operation of the data transfer power supply 224 is stopped, and the spiral magnetic structure pair 242 is moved on the data write line 230 in the longitudinal direction (−Y direction) by the drive of the data write power supply 233. The data reaches the erase area 232, collides with the lead wire, and is erased.

According to the second embodiment, the spiral magnetic structure pairs 241 and 242 move stably and at high speed by current driving and have a small threshold of movement by current driving as compared with conventional magnetic structures (such as magnetic bubbles). By being formed in the magnetic element 210, it is possible to obtain a non-volatile memory device that operates stably with lower power consumption than the prior art. Further, the data transfer power supply 224 and the data write power supply 233, for example, drive the current at a current density of about 10 ⁶ A / m ² or more and about 10 ¹⁰ A / m ² or less to drive the pair of spiral magnetic structures 241 and 242 with current. By doing so, the effect of reducing power consumption can be enhanced.

[Embodiment 3]
FIG. 21 is a diagram showing a magnetic memory device 300 according to the third embodiment of the present invention.
The magnetic memory device 300 includes a magnetic element (or magnetic memory element) 310 having a data transfer line 320 and a data write line 330. FIG. 21 shows the magnetic element 310 in which data has already been written. The magnetic element 310 corresponds to the stacked body 40 described in the first embodiment, that is, the magnetic element 1 in which the spiral magnetic structure pair is not formed. As shown in FIG. 22 and the like, the data transfer line 320 of the magnetic element 310 is provided between the first magnetic layer 325, the second magnetic layer 326, and between the first magnetic layer 325 and the second magnetic layer 326. A nonmagnetic layer 327 is provided. The magnetic element 310 is formed by vapor deposition of each layer in the stacked body 40 and photolithography.

  The data transfer line 320 is a magnetic wire having a loop shape in plan view (FIG. 21). However, the data transfer line 320 is not closed at a position of a data transfer drive unit 380 described later, that is, has an open loop shape. Reference numeral 341 indicates a pair of spiral magnetic structures formed on the data transfer line 320. The data transfer line 320 is divided into a plurality of data areas 321 and 322. In a state where data as shown in FIG. 21 is written in the magnetic element 310, the vortex magnetic structure pair 341 is formed in the data area 321, and the vortex magnetic structure pair 341 is not formed in the data area 322. The data areas 321 and 322 are provided at regular intervals. One data area corresponds to 1-bit data. The data transfer line 320 has a linear region 323 (extending in the X direction in FIG. 21) and an arc region 324. The X direction shown in FIG. 21 is the longitudinal direction of the linear region 323. In the arc region 324, the data region has a shape that expands from the inner peripheral side toward the outer peripheral side.

  The data write line 330 is provided in the straight line region 323 of the data transfer line 320 so as to intersect the data transfer line 320, and extends in the Y direction in FIG. The Y direction shown in FIG. 21 is the longitudinal direction of data write line 330. Reference numeral 342 indicates a pair of spiral magnetic structures formed on the data write line 330. Data write line 330 is connected to data write power supply 333 via a lead wire. The data write power supply 333 functions as a data write drive unit that applies a voltage between both ends of the data write line 330 to drive the current of the spiral magnetic structure pair 342 and to move on the data write line 330. To do.

  A data generation region 331 in which a vortex magnetic structure pair 342 is generated is located on one end side of the data write line 330, and data on which the vortex magnetic structure pair 342 is erased on the other end side of the data write line 330. An erase area 332 is located.

  The magnetic memory device 300 further includes the laser light source 250 and the magnetic field generator 260 described in the second embodiment. The configurations and operations of the laser light source 250 and the magnetic field generator 260 are the same as those in the second embodiment, and a description thereof will be omitted. The magnetic memory device 300 further includes a magnetoresistive sensor 370 provided in the linear region 323 of the data transfer line 320. Since the magnetoresistive sensor 370 has the same configuration as the magnetoresistive sensor 270 described in the second embodiment, the description of the configuration and operation thereof is omitted.

  The magnetic memory device 300 further includes a data transfer drive unit 380 provided in the linear region 323 of the data transfer line 320. The data transfer drive unit 380 includes an insulating stacked body 381, a pair of electrodes 382 and 383, and a data transfer power supply 384.

As shown in FIG. 22, one end (first end) 328 and the other end (second end) 329 of the data transfer line 320 having an open loop shape are provided at a distance in the longitudinal direction (X direction). . The insulating stacked body 381 is provided so as to connect the first end 328 and the second end 329 of the data transfer line 320. The insulating stacked body 381 includes insulating layers 385, 386, and 387. The insulating layers 385 and 386 are made of a ferromagnetic insulator such as MnZn ferrite ((Mn, Zn) Fe ₂ O ₄ ), and the insulating layer 387 is a nonmagnetic insulator such as SiO ₂ (silicon dioxide) or normal. Made of magnetic insulator. However, as long as the insulating layer 387 is sufficiently thin, the insulating layer 387 may be made of the same ferromagnetic insulator as the insulating layers 385 and 386.

  The pair of electrodes 382 and 383 are provided adjacent to both ends in the longitudinal direction (X direction) of the insulating stacked body 381 with the first magnetic layer 325 and the second magnetic layer 326 of the data transfer line 320 interposed therebetween. . The pair of electrodes 382 and 383 extend in the width direction (+ Y direction) intersecting the longitudinal direction (X direction) of the linear region 323 of the data transfer line 320. Although not shown, the first magnetic layer 325, the second magnetic layer 326, and the nonmagnetic layer 327 of the data transfer line 320 are all on the inner end face (+ Y direction side end face) of the loop of the magnetic element 310 and a pair of electrodes 382. , 383, respectively. The data transfer power supply 384 is electrically connected to the pair of electrodes 382 and 383, and applies a voltage between the pair of electrodes 382 and 383.

  Writing data to the data transfer line 320 and erasing data written to the data transfer line 320 are performed by writing data to the data transfer line 220 and erasing data written to the data transfer line 220 described in the second embodiment. Since it is performed in the same manner as in FIG.

  When data written to the data transfer line 320 is read, the data transfer power supply 384 is driven. At this time, in the data transfer drive unit 380, as shown in FIG. 22, a current flows from the data transfer line 320 to the electrode 382 (arrows 1001 and 1002), and a current flows from the electrode 383 to the data transfer line 320 (arrow 1003). , 1004). Thus, when a current flows around the insulating laminated body 381, a magnetic field is generated in a direction in which the vortex magnetic structure pair 341 is moved on the data transfer line 320. The spiral magnetic structure pair 341 moving on the data transfer line 320 is detected as a voltage change by the magnetoresistive sensor 270.

  In the second embodiment, by making the data transfer line 220 linear, the pair of spiral magnetic structures 241 and 242 that have passed through the reading unit (the magnetoresistive sensor 270) collide with the lead wire at the end of the data transfer line 220. A data passage area 223 is provided so as not to disappear. The data passage area 223 becomes longer according to the amount of data stored in the data transfer line 220. On the other hand, in the third embodiment, it is not necessary to provide an area corresponding to the data passing area 223 by forming the data transfer line 320 in a loop shape. Therefore, the magnetic memory device 300 according to the third embodiment has an effect that it can be reduced in size as compared with the magnetic memory device 200 according to the second embodiment.

  Next, a modification of the data transfer drive unit will be described with reference to FIGS. In the modification shown in FIGS. 23 to 28, only the insulating layer and the pair of electrodes constituting the data transfer drive unit are given different reference numerals from FIG. 22, and the same reference numerals 320 are assigned to the data transfer lines. It is attached. A data transfer power supply 384 that is electrically connected to the pair of electrodes is not shown.

  In the modification shown in FIGS. 23 and 24, the data transfer line 320 is displaced in the vertical direction (Z direction) and overlaps in the longitudinal direction (X direction) at the position of the data transfer drive unit. ) Is provided. One end and the other end of the data transfer line 320 are connected in the vertical direction (Z direction) by the insulating layer 481. An electrode 482 is provided on the end face on one end (first end) side of the data transfer line 320, and an electrode 483 is provided on the end face on the other end (second end) side of the data transfer line 320.

  In the modification shown in FIG. 23, the electrode 482 extends upward (+ Z direction) from one end of the data transfer line 320, and the electrode 483 extends from the other end of the data transfer line 320 in the longitudinal direction (+ X direction). When the data transfer power supply 384 is driven, a current flows from the data transfer line 320 to the electrode 483 (arrows 1005 and 1006), and a current flows from the electrode 482 to the data transfer line 320 (arrow 1007).

  In the modification shown in FIG. 24, the electrode 482 extends in the longitudinal direction (−X direction) from one end of the data transfer line 320, and the electrode 483 extends in the width direction (−Y direction) from the other end of the data transfer line 320. . When the data transfer power supply 384 is driven, a current flows from the data transfer line 320 to the electrode 483 (arrows 1008 and 1009), and a current flows from the electrode 482 to the data transfer line 320 (arrow 1010).

  In the modification shown in FIGS. 25 and 26, as in the example shown in FIG. 22, one end and the other end of the data transfer line 320 are spaced apart in the longitudinal direction (X direction) at the position of the data transfer drive unit. Is provided. One end and the other end of the data transfer line 320 are connected to each other by an insulating layer 581 extending in the longitudinal direction (X direction) along the data transfer line 320 on the lower surface of the second magnetic layer 326.

  In the modification shown in FIG. 25, an electrode 582 is provided on the end face on one end (first end) side of the data transfer line 320, and an electrode 583 is provided on the end face on the other end (second end) side of the data transfer line 320. . The electrodes 582 and 583 extend upward (+ Z direction) from one end and the other end of the data transfer line 320, respectively. When the data transfer power supply 384 is driven, a current flows from the data transfer line 320 to the electrode 582 (arrows 1011 and 1012), and a current flows from the electrode 583 to the data transfer line 320 (arrows 1013 and 1014).

  In the modification shown in FIG. 26, the electrode 582 is on one end (first end) side of the data transfer line 320 and on the first magnetic layer 325, and is on the other end (second end) side of the data transfer line 320. An electrode 583 is provided on the first magnetic layer 325. The electrodes 582 and 583 respectively extend upward (+ Z direction) from the upper surface of the first magnetic layer 325 of the data transfer line 320. When the data transfer power supply 384 is driven, a current flows from the data transfer line 320 to the electrode 582 (arrows 1015 and 1016), and a current flows from the electrode 583 to the data transfer line 320 (arrows 1017 and 1018).

  27 and FIG. 28, similarly to the example shown in FIG. 22, one end (first end) 328 and the other end (second end) 329 of the data transfer line 320 at the position of the data transfer drive unit. Are provided at a distance in the longitudinal direction (X direction). In the data transfer line 320, the second magnetic layer 326 is provided so as to protrude in the longitudinal direction (X direction) with respect to the first magnetic layer 325 and the nonmagnetic layer 327. The first end 328 and the second end 329 of the data transfer line 320 are the first end 328 a and the second end 329 a of the first magnetic layer 325 and the nonmagnetic layer 327, the first end 328 b of the second magnetic layer 326, And two ends 329b. An insulating layer 681 is provided between the first end 328 b and the second end 329 b of the second magnetic layer 326, thereby connecting the first end 328 and the second end 329 of the data transfer line 320. Electrodes 682 and 683 are provided on the first magnetic layer 325 and the nonmagnetic layer 327 on the first end 328 a side end surface and the second end 329 a side end surface, respectively, on the upper surface of the second magnetic layer 326.

  In the modification shown in FIG. 27, the electrode 682 extends upward (+ Z direction) from the upper surface of the second magnetic layer 326, and the electrode 683 extends upward (+ Z direction) from the upper surface of the second magnetic layer 326. Yes. When the data transfer power supply 384 is driven, a current flows from the data transfer line 320 to the electrode 682 (arrows 1019 and 1020), and a current flows from the electrode 683 to the data transfer line 320 (arrow 1021).

  In the modification shown in FIG. 28, the electrode 682 extends in the width direction (+ Y direction) from the upper surface of the second magnetic layer 326, and the electrode 683 extends in the width direction (+ Y direction) from the upper surface of the second magnetic layer 326. Yes. When the data transfer power supply 384 is driven, a current flows from the data transfer line 320 to the electrode 682 (arrows 1022 and 1023), and a current flows from the electrode 683 to the data transfer line 320 (arrows 1024 and 1025).

  As shown in FIGS. 22 to 28, in the magnetic memory device 300, the pair of electrodes included in the data transfer drive unit can have a desired shape and arrangement, and a degree of freedom in product design can be obtained.

  As mentioned above, although this invention was demonstrated by embodiment, this invention is not limited to the said embodiment. The features described in each embodiment may be freely combined. In addition, various improvements, design changes, and deletions may be added to the embodiment.

For example, in the magnetic element 1 according to the first embodiment, the example having the three-layer film structure in which the nonmagnetic layer 30 is provided between the first magnetic layer 10 and the second magnetic layer 20 has been described. At present, research is being conducted to form antiferromagnetic coupling with a bilayer film of a ferromagnetic material and an oxide ferromagnetic material without providing a nonmagnetic layer. For example, Fe / Fe ₃ O ₄ (iron / tetraoxide) It has been confirmed that the two-layered film of (iron) is antiferromagnetically coupled. It should be understood that the present invention includes a magnetic element having such a two-layer film structure.

DESCRIPTION OF SYMBOLS 1 Magnetic element 10 1st magnetic layer 11 Vortex magnetic structure 20 (formed in the 1st magnetic layer) 2nd magnetic layer 21 Vortex magnetic structure 30 (formed in the 2nd magnetic layer) Nonmagnetic layer 40 Laminate 200, 300 Magnetic memory device 210, 310 Magnetic element (magnetic memory element)
220, 320 Data transfer lines 230, 330 Data write lines 241, 242, 341, 342 Spiral magnetic structure pair 224 Data transfer power supply 233, 333 Data write power supply 250 Laser light source 260 Magnetic field generator 270, 370 Magnetoresistive sensor 380 Data Transfer drive unit 381 Insulating laminate 382 Pair of electrodes 384 Data transfer power supply

Claims (13)

A first magnetic layer and a second magnetic layer magnetized in a direction perpendicular to the plane and antiferromagnetic exchange coupled;
The first magnetic layer and the second magnetic layer are formed with a pair of spiral magnetic structures whose rotational directions are opposite to each other when viewed from the first magnetic layer side,
The direction of the magnetic moment is antiparallel between the center of each vortex magnetic structure and the outside of the vortex magnetic structure.
Magnetic element. A nonmagnetic layer is provided between the first magnetic layer and the second magnetic layer;
The magnetic element according to claim 1. Providing a laminate comprising a first magnetic layer and a second magnetic layer magnetized in a perpendicular direction and antiferromagnetic exchange coupled;
Irradiating a part of the first magnetic layer with a laser beam to perform local heating;
Applying an external magnetic field in a direction opposite to the magnetization direction of the first magnetic layer, and reversing the magnetic moment in a part of the first magnetic layer,
A method for manufacturing a magnetic element. In the heating step, the temperature of a part of the first magnetic layer is raised to a temperature higher than the Curie temperature,
In the step of applying the external magnetic field, an external magnetic field having a magnitude such that the magnetic moment is reversed in a part of the first magnetic layer and the magnetic moment is not reversed in the other part of the first magnetic layer.
The method for manufacturing a magnetic element according to claim 3. A magnetic element;
A writing unit for writing data to the magnetic element;
A reading unit for reading data written in the magnetic element,
The magnetic element has a first magnetic layer and a second magnetic layer that are magnetized in a perpendicular direction and are antiferromagnetic exchange coupled,
The writing unit is configured to form a pair of spiral magnetic structures whose rotation directions are opposite to each other when viewed from the first magnetic layer side in the first magnetic layer and the second magnetic layer,
The reading unit is configured to read whether or not the pair of spiral magnetic structures exists in the magnetic element as 1-bit data,
The direction of the magnetic moment is antiparallel between the center of each vortex magnetic structure and the outside of the vortex magnetic structure.
Magnetic memory device. The reading unit has a magnetoresistive element,
The magnetoresistive element includes the first magnetic layer or the second magnetic layer in a part thereof,
The magnetic memory device according to claim 5. The magnetic element has a data transfer line provided with the read unit and a data write line provided with the write unit,
The data write line is provided to intersect the data transfer line.
The magnetic memory device according to claim 5. A drive unit that current-drives the pair of vortex magnetic structures and moves over the data transfer line;
The magnetic memory device according to claim 7. The data transfer line has an open loop shape having a first end and a second end,
The drive unit is provided so as to connect the first end and the second end, and is in contact with the first end and the second end and adjacent to the insulating layer. A first drive electrode and a second drive electrode; and a power supply for applying a voltage between the first drive electrode and the second drive electrode.
The magnetic memory device according to claim 8. The drive unit current-drives the pair of vortex magnetic structures at a current density of about 10 ⁶ A / m ² or more and about 10 ¹⁰ A / m ² or less;
The magnetic memory device according to claim 8 or 9. The read unit is provided in an intersection region between the data transfer line and the data write line.
The magnetic memory device according to claim 8. The writing unit includes a heating unit that locally heats the first magnetic layer of the magnetic element, and a magnetic field generation unit that applies an external magnetic field to the magnetic element.
The magnetic memory device according to claim 5. The heating unit is a laser light source.
The magnetic memory device according to claim 12.