JP2022083931A - Domain wall moving element, magnetic storage element, spatial light modulator, and magnetic memory - Google Patents

Abstract

To provide a domain wall moving element capable of high-speed writing without increasing the current density for the domain wall moving element for writing by moving the domain wall of a magnetic fine wire by current supply.SOLUTION: A domain wall moving element 10 includes a magnetic thin wire 1 formed by laminating a magnetic layer 11 having a vertical magnetic anisotropy and a channel layer 12 having a spin Hall effect to form a fine line along the x direction, and a bar magnet-shaped nanomagnet 51 along the magnetic thin wire 1 arranged under the magnetic thin wire 1. Due to application of the leakage magnetic field Hass of the nanomagnet 51 in the -x direction, a domain wall DW generated in the magnetic layer 11 is stabilized by a right-turning nail-shaped magnetic structure. When a current is supplied to the magnetic wire 1 in the +x direction, electrons having a spin in the -y direction accumulate near the interface of the channel layer 12 with the magnetic layer 11, and the magnetic moment in the magnetic wall DW rotates counterclockwise in the xz plane, and the magnetic wall DW moves in the +x direction.SELECTED DRAWING: Figure 2A

Description

Application for application of Article 30, Paragraph 2 of the Patent Act The website of AIP Advances published online by American Institute of Physics on January 23, 2020: https: // aip. scitation. Presented at org / doi / full / 10.1063 / 1.5130488

The present invention relates to a domain wall moving element, a magnetic storage element including the domain wall moving element, a magnetic memory, and a spatial light modulator.

In a magnetic resistance random access memory (MRAM) in which the high and low resistance of a magnetic resistance effect element in a memory cell is used as binary data, writing, that is, a part of the magnetic film (free layer) of the magnetic resistance effect element is written. ), The STT (Spin Transfer Torque) -MRAM, which supplies current vertically to the membrane surface in order to increase the speed and reduce the size of the cell, compared to the initial magnetic field application method. Has been developed. And for further speeding up, magnetic wall movement type MRAM (for example, Patent Document 1 and Non-Patent Document 1) and SOT (Spin Orbit Torque: spin orbit torque) -MRAM (for example, Patent Documents 2 and 3) have been developed. Has been done.

In the domain wall moving method, the free layer of the magnetoresistive effect element is formed in a thin wire shape extended on both sides, and a current is supplied in the longitudinal direction thereof to change the magnetization direction between two predetermined points in the longitudinal direction. Specifically, a magnetic body (hereinafter referred to as a magnetic domain) formed in a thin line having a width of several nm to several hundred nm tends to generate two or more magnetic domains in the longitudinal direction thereof, and further in the longitudinal direction (thin wire direction). When a current is supplied at a predetermined current density or higher, the magnetic domain wall generated so as to separate the magnetic domains moves in the opposite direction (toward the positive electrode side) of the current due to the STT effect. Further, a magnetic optical spatial light modulator has been developed in which a magnetic wire is formed of a magnetic optical material to form a light modulation element by utilizing the magnetization reversal in a predetermined region of the magnetic wire (for example, a patent). Documents 4 and 5). Further, a magnetic memory has been developed in which the movement of the domain wall is speeded up by applying a magnetic field to the magnetic wire in the same direction as the current supply direction (for example, Patent Document 6).

The SOT-MRAM is provided by laminating a spin Hall layer having a Spin Hall effect (SHE) such as Ta (tantal) on a free layer of a magnetoresistive effect element. In the spin Hall layer, when a current is supplied in one direction (x direction) in the film surface (xy surface), electrons having spins in opposite directions in the y direction are separately accumulated in the upper and lower surface layers and are free. Electrons near the interface with the layer reverse the magnetization direction of the free layer. It is known that the SOT effect also acts on the domain wall movement in the magnetic fine wire (for example, Non-Patent Documents 2 to 6), and in Non-Patent Document 4, the direction of the spin that moves the domain wall differs depending on the magnetic structure of the magnetic wall. Has been reported.

Japanese Patent No. 5598697 International Publication No. 2017/090730 International Publication No. 2019/054484 Japanese Patent No. 4939489 Japanese Unexamined Patent Publication No. 2018-073871 Japanese Unexamined Patent Publication No. 2019-029595

S. Fukami, T. Suzuki, K. Nagahara, N. Ohshima, Y. Ozaki, S. Saito, R. Nebashi, N. Sakimura, H. Honjo, K. Mori, C. Igarashi, S. Miura, N. Ishiwata, T. Sugibayashi, "Low-Current Perpendicular Domain Wall Motion Cell for scalable High-Speed MRAM", 2009 Symposium on VLSI Technology Digest of Technical Papers, 12A-2 Luqiao Liu, O. J. Lee, T. J. Gudmundsen, D. C. Ralph, R. A. Buhrman, "Current-Induced Switching of Perpendicularly Magnetized Magnetic Layers Using Spin Torque from the Spin Hall Effect", Physical Review Letters, Volume 109, 096602, 2012 Soo-Man Seo, Kyoung-Whan Kim, Jisu Ryu, Hyun-Woo Lee, Kyung-Jin Lee, "Current-induced motion of a transverse magnetic domain wall in the presence of spin Hall effect", Applied Physics Letters, Volume 101, 022405 (2012) A. V. Khvalkovskiy, V. Cros, D. Apalkov, V. Nikitin, M. Krounbi, K. A. Zvezdin, A. Anane, J. Grollier, A. Fert, "Matching domain-wall configuration and spin-orbit torques for efficient domain-wall" motion ", Physical Review B87, 020402 (R), 2013 Kab-Jin Kim, et al., "Fast domain wall motion in the vicinity of the angular momentum compensation temperature of ferrimagnets", Nature Materials volume 16, pp. 1187-1192, 2017 Yuichiro Kurokawa, Hiroyuki Awano, "Pt / [Tb / Co] n Effect of Pt layer on current-induced domain wall movement of multi-layer wiring", 40th Annual Meeting of the Magnetic Society of Japan, 5pE-3, 2016

If the supply of a current having a high current density is repeated in order to move the magnetic domain wall in the magnetic thin wire, the magnetic fine wire may deteriorate and the life of the MRAM or the like may be shortened. Further, from the viewpoint of power saving, operation at a lower current density is particularly desirable in a spatial light modulator in which a magnetic thin wire having a certain width and thickness is used as an optical modulation element. In addition, the effect of magnetization reversal and domain wall movement due to the SOT effect tends to decrease as the magnetic film becomes thicker, the thermal disturbance resistance of magnetization is insufficient for a storage element, and the magneto-optical effect is small for a light modulation element. .. In the domain wall movement by magnetic field assist as described in Patent Document 6, the movement is hindered when the magnetic field is applied in the direction opposite to the current supply direction. Therefore, in order to enable the reciprocating movement of the magnetic field, the magnetic field is applied. It is necessary to provide a magnetic field applying means capable of switching ON / OFF or reversing the direction of the magnetic field, and there is room for improvement.

The present invention was devised in view of the above problems, and is a magnetic memory and a spatial optical modulator capable of high-speed writing without increasing the current density of the supplied current, and a magnetic storage element and a domain wall moving element thereof. Is the challenge.

Since the movement of the domain wall in the magnetic domain wall due to the SOT effect differs depending on the magnetic structure of the magnetic wall, the present inventors have come up with a configuration in which the magnetic structure of the domain wall is stabilized by an external magnetic field.

That is, the magnetic wall moving element according to the present invention has a magnetic thin wire formed by laminating a magnetic layer made of a vertically magnetic anisotropic material and a channel layer having a spin hole effect to form a fine wire, and a magnetic thin wire under the magnetic fine wire. A magnetic field applying member made of a hard magnetic material having in-plane magnetic anisotropy arranged on the side is provided, and the magnetic field applying member is fixed in a predetermined direction in the thin wire direction of the magnetic wire and emits. When a magnetic field is applied to the magnetic thin wire and a current is supplied to the magnetic thin wire in the thin wire direction, the magnetic wall generated in the magnetic layer moves in a direction corresponding to the current supply direction in the thin wire direction. It is characterized by. With such a configuration, the domain wall moving element can reverse the magnetization within the domain wall moving range at a high speed with respect to the current density of the supplied current.

In the magnetic storage element according to the present invention, in the magnetic fine wire of the domain wall moving element, the channel layer is laminated under the magnetic layer, and a non-magnetic metal film or a non-magnetic metal film or a non-magnetic metal film is formed on the upper surface of the magnetic layer within the moving range of the magnetic wall. A reference layer made of a vertically magnetic anisotropy material is laminated and provided with an insulating film interposed therebetween. With such a configuration, the magnetic storage element can write at a high speed with respect to the current density of the supplied current.

The spatial light modulator according to the present invention is provided with the domain wall moving element in a pixel, and light is incident from above and reflected. Further, the magnetic memory according to the present invention includes the magnetic storage element in the memory cell. With such a configuration, the spatial light modulator and the magnetic memory can write at high speed with respect to the current density of the supplied current.

According to the domain wall moving element and the magnetic storage element according to the present invention, the current density of the supplied current is suppressed to a low level, and the magnetic fine wire is unlikely to deteriorate. According to the spatial light modulator and the magnetic memory according to the present invention, high-speed writing is possible, and the life is extended and the power is saved.

It is sectional drawing which schematically explains the structure of the domain wall moving element which concerns on 1st Embodiment of this invention. It is a schematic diagram explaining the magnetization direction of the magnetic thin wire of the domain wall moving element shown in FIG. 1 and the applied magnetic field. It is a schematic diagram explaining the magnetization direction of the magnetic thin wire of the domain wall moving element shown in FIG. 1 and the applied magnetic field. It is a conceptual diagram explaining the magnetic structure of the right-turning nail-type domain wall in a magnetic thin wire, and the movement of the domain wall due to the spin-orbit torque effect. It is a conceptual diagram explaining the magnetic structure of the right-turning nail-type domain wall in a magnetic thin wire, and the movement of the domain wall due to the spin-orbit torque effect. It is a conceptual diagram explaining the magnetic structure of a left-turning domain wall in a magnetic thin wire, and the movement of the domain wall due to the spin-orbit torque effect. It is a conceptual diagram explaining the magnetic structure of a left-turning domain wall in a magnetic thin wire, and the movement of the domain wall due to the spin-orbit torque effect. It is an equivalent circuit diagram of the spatial light modulator which concerns on embodiment of this invention. It is sectional drawing schematically explaining the structure of the magnetic memory element provided with the domain wall moving element which concerns on 2nd Embodiment of this invention. It is a schematic diagram explaining the magnetization direction and the applied magnetic field of the magnetic memory element shown in FIG. It is a schematic diagram explaining the magnetization direction and the applied magnetic field of the magnetic memory element shown in FIG. It is an equivalent circuit diagram of the magnetic memory which concerns on embodiment of this invention. It is a schematic diagram explaining the structure of the magnetic storage element shown in FIG. 6 in a magnetic memory. It is sectional drawing which schematically explains the structure of the magnetic memory element provided with the domain wall moving element which concerns on the modification of 2nd Embodiment of this invention in a magnetic memory. It is sectional drawing which schematically explains the structure of the magnetic memory element provided with the domain wall moving element which concerns on the modification of 2nd Embodiment of this invention in a magnetic memory. It is a schematic diagram explaining the magnetization direction and the applied magnetic field of the magnetic memory element provided with the domain wall moving element which concerns on 3rd Embodiment of this invention. It is a schematic diagram explaining the magnetization direction and the applied magnetic field of the magnetic memory element provided with the domain wall moving element which concerns on 3rd Embodiment of this invention. It is sectional drawing which schematically explains the structure of the domain wall moving element which concerns on 4th Embodiment of this invention. It is a micrograph of the sample of the example which simulated the domain wall moving element which concerns on this invention. It is a magnetization curve represented by the magnetic field dependence of the car rotation angle of the magnetic fine wire of the sample of the example which simulated the domain wall moving element which concerns on this invention. It is a magnetization curve represented by the magnetic field dependence of the car rotation angle of the magnetic thin wire of the sample of the comparative example simulating the conventional domain wall moving element. It is a graph of the current density dependence of the moving speed of the up-down domain wall in the sample of the Example which simulated the domain wall moving element which concerns on this invention. It is a graph of the current density dependence of the moving speed of the down-up domain wall in the sample of the Example which simulated the domain wall moving element which concerns on this invention. It is a graph of the magnetic field dependence of the moving speed of the up-down domain wall in the sample of the Example which simulated the domain wall moving element which concerns on this invention. It is a graph of the magnetic field dependence of the moving speed of the down-up domain wall in the sample of the Example which simulated the domain wall moving element which concerns on this invention. It is a graph of the current density dependence of the domain wall moving speed of the sample of the comparative example simulating the conventional domain wall moving element.

Hereinafter, a mode for realizing a magnetic domain wall moving element, a magnetic storage element, a magnetic memory, and a spatial light modulator according to the present invention will be described with reference to the drawings. Domain wall moving elements, magnetic storage elements, magnetic memories, and spatial light modulators shown in the drawings, and their elements may be exaggerated in size, positional relationship, etc. for the sake of clarity, and the shape. And the structure may be simplified.

[First Embodiment]
(Light modulation element)
As shown in FIG. 1, the optical modulation element (magnetic wall moving element) 10 according to the first embodiment of the present invention has a magnetic layer 11 made of a vertically magnetically anisotropic material and a channel layer 12 having a spinhole effect. A magnetic thin wire 1 formed by laminating in order from the beginning to form a fine wire, and a nanomagnet whose magnetization direction is unidirectional in the thin wire direction of the magnetic fine wire 1 arranged below the magnetic fine wire 1 at a distance from the channel layer 12. (Magnetic field application member) 51, and further, electrodes 61 and 62 connected to the lower surfaces (channel layer 12) at both ends of the magnetic wire 1 are provided. Further, in the light modulation element 10, an insulator is provided in a blank portion such as around the magnetic thin wire 1. In the present specification, the thin wire direction of the magnetic thin wire 1 is referred to as an x direction, the thin wire width direction is referred to as a y direction, and the thickness direction is referred to as a z direction. The light modulation element 10 is used as a pixel of a spatial light modulator, and reflects light incident from above to emit light whose polarization direction is changed to a binary angle (see, for example, Patent Documents 4 and 5). .. Pixels refer to means for displaying information (bright / dark) in the smallest unit of display by a spatial light modulator.

The magnetic layer 11 is a main member of the light modulation element 10, and indicates a desired direction in which the magnetization direction of a part of the region is upward or downward, and the polarization direction is set to 2 when the incident light is reflected due to the Kerr effect. Change to the angle of value (+ θ _k / −θ _k ). The magnetic layer 11 is made of a vertically magnetic anisotropy material formed in a fine line shape, and is separated in the fine line direction by a magnetic domain wall DW as shown in FIGS. 2A and 2B, and has different magnetization directions (hatched in the figure). It is divided into two magnetic domains (represented by arrows), that is, a downward magnetic domain and an upward magnetic domain. As will be described later, in the magnetic layer 11, the domain wall DW is moved in the wire direction by electrical means, and the magnetization direction between the start point and the end point of the domain wall DW movement changes before and after the movement. The region between the start point and the end point of the movement of the domain wall DW in the magnetic layer 11 is referred to as a magnetization reversible region 1 _SW , and can be an opening of a pixel. The light modulation element 10 changes the light reflected by the magnetization reversible region 1 _SW of the magnetic layer 11 in a desired polarization direction. Therefore, it is preferable that the magnetic layer 11 is made of a vertically magnetic anisotropic material having a relatively small coercive force, and more preferably has a high magneto-optical effect, and is used as a magnetoresistive element of an MRAM or the like. It is possible to apply known magnetic materials used for the magnetized free layer of applicable CPP-GMR (Current Perpendicular to the Plane Giant MagnetoResistance) elements and TMR (Tunnel MagnetoResistance) elements. can. Specifically, a multilayer film such as a Co / Pd multilayer film in which transition metals such as Fe, Co, and Ni and precious metals such as Pd and Pt are alternately and repeatedly laminated at a film thickness ratio of about 1: 2 to 4, Tb. Examples thereof include alloys of rare earth metals such as Fe-Co and Gd-Fe and transition metals (RE-TM alloys), FePt, FePd, _{CrPt 3} and the like as L10-based ordered alloys. In this embodiment, a Gd—Fe alloy having a small coercive force and a high magneto-optical effect is particularly suitable.

It is preferable that each of the magnetic layer 11 and the channel layer 12 constituting the magnetic thin wire 1 is a linear shape having a uniform thickness and width. The magnetic layer 11 is formed in a thin line shape sufficiently long with respect to the thickness and width. Further, the smaller the cross-sectional area, which is the product of the thickness and the width, of the magnetic layer 11, the smaller the current supplied to the magnetic thin wire 1. On the other hand, the magnetic layer 11 preferably has a certain thickness and width in order to maintain the magnetization, and the larger the thickness, the higher the degree of optical modulation (the larger the car rotation angle θ _k ), which is specific. The thickness is preferably 5 nm or more, more preferably 10 nm or more. However, although it depends on the material, when the thickness of the magnetic layer 11 exceeds about 20 nm, the increase in the optical modulation degree is slowed down, and when the film is further thickened, it may be difficult to maintain the vertical magnetic anisotropy. Further, if the magnetic layer 11 is thick, the domain wall DW becomes difficult to move. Therefore, the thickness of the magnetic layer 11 is preferably 30 nm or less, more preferably 20 nm or less. Further, it is preferable that the magnetization reversible region 1 _SW of the magnetic layer 11 which is the opening of the pixel is wide, and the width and the length of the magnetization reversible region 1 _SW in the thin line direction are 200 to 200, although it depends on the wavelength of the incident light. It is preferably about 300 nm or more. Further, in the magnetic layer 11, the regions adjacent to both outer sides of the magnetization reversible region 1 _SW in the wire direction are defined as regions in which the magnetization direction is fixed (magnetization fixed region) 1 _FX1 and 1 _FX2 , and the length in the wire direction is the wire width, respectively. It is preferably ½ or more of. Further, the magnetic layer 11 (magnetic thin wire 1) is further stretched and formed so that the electrodes 61 and 62 are connected to both outer sides in the thin wire direction of the magnetization fixing regions 1 _FX1 and 1 _FX2 . The magnetization direction of the magnetic layer 11 in the connection region with the electrodes 61 and 62 is not particularly specified. In FIGS. 2A and 2B, a downward magnetic domain is formed on the electrode 62, and a domain wall DW'is formed at the boundary with the magnetization fixed region 1 _FX2 .

The channel layer 12 is a path through which an electric current flows, and is laminated on one side of the magnetic layer 11, here on the lower surface, and is formed in the same plan view shape as the magnetic layer 11. The channel layer 12 is a thin film that generates a spin current by the spin Hall effect (SHE) when a current flows. For example, Ta, Pt, W having a high specific gravity among paramagnetic transition metals are applied. Further, a topological insulator such as BiSb or BiSe can be applied to the channel layer 12. The thickness of the channel layer 12 is preferably 1 nm or more, and preferably 10 nm or less.

The nanomagnet 51 is a very small bar magnet whose length in the x direction is longer than the length in the y direction and the thickness along the thin wire direction of the magnetic fine wire 1, and here, the + x side is the N pole. Unless otherwise specified, in each drawing, the nanomagnet 51 and the nanomagnets 52 and 53 described later are represented by having polarities “N” and “S” and further having hatching on the N pole side. Further, in FIG. 1, the lines of magnetic force from the nanomagnet 51 are represented by broken lines. The nanomagnet 51 is made of a hard magnetic material having in-plane magnetic anisotropy, and for example, a transition metal such as Fe, Co, Ni and a noble metal such as Pd, Pt have a film thickness ratio of about 2 to 4: 1. A multilayer film such as a Co / Pt multilayer film laminated repeatedly alternately is applied. In the nanomagnet 51, the leakage magnetic field reaches the magnetic layer 11, and the magnetic field _Hass is applied to the magnetization reversible region 1 _SW in the −x direction opposite to the polarity of the nanomagnet 51. As will be described later, the magnetic field _Hass has a size that allows the magnetic wall DW of the magnetic layer 11 to move when a current I _w of a predetermined magnitude is supplied to the magnetic thin wire 1, and is a current of the magnetic layer 11. Coercive force when I _w is supplied (temporary coercive force) Hc _f ´ (Hc _f ′ ≦ Hc _f , Hc _f : Coercive force when the current of the magnetic layer 11 is not supplied) (H _ass <Hc Larger is preferable in _f ´). Further, the nanomagnet 51 further applies magnetic fields −H _pin and + H _pin in the −z direction and the + z direction to the magnetization fixed regions 1 _FX1 and 1 _FX2 of the magnetic layer 11. The magnetic field −H _pin and + H _pin are preferably larger than the temporary coercive force Hc _f ′ of the magnetic layer 11 (H _pin > Hc _f ′), and ideally larger than the coercive force Hc _f ′ of the magnetic layer 11. be. Therefore, it is preferable that both ends (both poles) of the nanomagnet 51 are arranged directly below the magnetization fixed regions 1 _FX1 and 1 _FX2 of the magnetic layer 11, respectively. Therefore, the nanomagnet 51 is formed so that the length in the wire direction is shorter than that of the magnetic wire 1 and the magnetization reversible region 1 _SW or more, and the width is equal to or more than that of the magnetic wire 1. Further, the nanomagnet 51 is preferably arranged closer to the magnetic layer 11 in order to apply the magnetic fields _Hass , −H _pin , and + H _pin to the magnetic layer 11 with sufficient strength. Here, the nanomagnet 51 may be in contact with the magnetic thin wire 1 (magnetic layer 11 or channel layer 12), but since a part of the current supplied to the magnetic thin wire 1 flows, the current is increased. Need arises. Therefore, it is preferable that the nanomagnet 51 is separated from the magnetic thin wire 1 and the electrodes 61 and 62 electrically connected to the magnetic thin wire 1 by an insulating film, and specifically arranged with a space of 3 nm or more.

The electrode 61 and the electrode 62 are terminals for supplying an electric current to the magnetic thin wire 1 from the outside in the thin wire direction (+ x direction, −x direction). Therefore, the electrodes 61 and 62 are connected to the magnetic layer 11 or the channel layer 12 on both outer sides of the magnetization reversible region 1 _SW of the magnetic layer 11. The electrodes 61 and 62 are general metal electrode materials such as metals such as Cu, Al, Au, Ag, Ta, Cr, Pt, and Ru and their alloys, and correspond to the magnitude of the current supplied to the magnetic wire 1. It is formed to the thickness and width of the metal. In the present embodiment, the electrodes 61 and 62 are provided by being connected to the channel layer 12 on the lower side of the magnetic wire 1. Therefore, the electrodes 61 and 62 are provided with sufficient gaps from both ends of the nanomagnet 51 so as not to shield the magnetic fields −H _pin and + H _pin applied to the magnetic layer 11 in the vicinity of both ends of the nanomagnet 51. It is preferable that the magnetic layer 11 is arranged outside the magnetization fixed regions 1 _FX1 and 1 _FX2 .

In the light modulation element 10, a known inorganic insulating material provided for a semiconductor element such as SiO ₂ , SiN, Al ₂ O ₃ is applied to the insulator provided in a blank portion such as between the magnetic wire 1 and the nanomagnet 51. However, different materials may be provided depending on the site. In particular, when the magnetic layer 11 is made of a material that is easily oxidized such as a RE-TM alloy, it is preferable to apply a non-oxide such as SiN or MgO to the portion in contact with the magnetic layer 11. Further, at the time of manufacturing the light modulation element 10 (spatial light modulator 90), such an insulating material is used as a protective film having a thickness of about 1 to 10 nm, and is continuous with the material forming the channel layer 12 and the magnetic layer 11, respectively. It is preferable to form a film.

(Domain wall movement in magnetic thin wire)
The domain wall movement of the light modulation element according to the present embodiment in the magnetic fine wire due to the current supply will be described with reference to FIGS. 3A, 3B, 4A, and 4B. In these drawings, the portion of the magnetic thin wire 1 including the domain wall DW in the magnetization reversible region 1 _SW (see FIGS. 2A and 2B) of the magnetic layer 11 is shown enlarged in the thin line direction (x direction). First, the magnetic structure of the domain wall will be described. In the magnetic layer 11 which is a ferromagnetic material, the magnetic moments m and m adjacent to each other do not suddenly switch from downward to upward at the boundary between the magnetic domain D1 having a downward magnetization direction and the magnetic domain D2 having an upward magnetization direction, and the adjacent magnetic moments m and m have the same direction. Since the exchange interaction that tries to align with each other works, the magnetic moment m arranged on the magnetic domain DW is gradually inclined from the magnetic domain D1 side to the magnetic domain D2 side. A domain wall having a magnetization direction in which the −x side faces downward and the + x side faces upward, such as the domain wall DW in these drawings, is referred to as a down-up domain wall. On the contrary, a domain wall whose magnetization direction is upward on the −x side and downward on the + x side is referred to as an up-down domain wall. Here, there are two types of magnetic structures in the domain wall of a magnetic material made of a vertically magnetic anisotropy material. One is that, as shown in FIGS. 3A, 3B, 4A, and 4B, the magnetic moment m in the domain wall DW is inclined toward the wire direction (x direction) perpendicular to the domain wall (yz plane). , A Neel-type domain wall that rotates 180 ° in the xz plane. The other is a Bloch-type magnetic wall in which the magnetic moment m is inclined toward the wire width direction (y direction) and rotates 180 ° in the magnetic wall surface (yz plane) (not shown). Further, in each domain wall, the rotation direction of the magnetic moment may indicate right-handed chirality and left-handed chirality. The domain wall DW shown in FIGS. 3A and 3B has a right-turning nail-type magnetic structure, and the domain wall DW shown in FIGS. 4A and 4B has a left-turning nail-type magnetic structure.

Normally, in a magnetic material having vertical magnetic anisotropy formed in a fine line shape, the domain wall moves while the magnetic structure changes alternately in these four ways. However, when the fine line width is sufficiently narrow, it tends to become a nail-type domain wall, and it changes in two ways, right turn and left turn. However, in the light modulation element (domain wall moving element) 10 according to the present embodiment, as shown in FIGS. 3A and 3B, the nanomagnet 51 always causes a magnetic field in a predetermined one direction (−x direction) in the thin line direction. Since _Hass is applied to the magnetic layer 11, the domain wall DW is stable with a right-turning nail-shaped magnetic structure regardless of the wire width. When the nanomagnet 51 is arranged on the upper side of the magnetic layer 11, as shown in FIGS. 4A and 4B, the magnetic field _Hass in the + x direction is applied to the magnetic layer 11, so that the nail turns left. It becomes a type magnetic wall DW.

When a current I _w is supplied to such a magnetic thin wire 1 via electrodes 61 and 62 in one direction (+ x direction) in the thin wire direction, as shown in FIG. 3A, a unit of yz plane is supplied to the channel layer 12. The current J per area flows in the + x direction. Then, in the channel layer 12, a spin current is induced by the spin Hall effect, and electrons e ^- having spins in opposite directions (-y direction, + y direction) in the line width direction are separated into upper and lower surface layers. Accumulate. Therefore, electrons e ⁻ having a spin in the −y direction are unevenly distributed in the vicinity of the interface with the upper magnetic layer 11. The electron e ^- having a spin in the -y direction rotates the magnetic moment m of the domain wall DW of the magnetic layer 11 counterclockwise in the xz plane. In FIGS. 3A, 3B, 4A, and 4B, an arrow indicating the rotation direction is attached to the magnetic moment m of the domain wall DW. At the same time, a current having a current density corresponding to the resistance difference from the channel layer 12 also flows through the magnetic layer 11. When this current density is sufficiently high, the coercive force of the magnetic layer 11 decreases from Hc _f to Hc _f ′ due to the generation of Joule heat and the temperature rises, the magnetic anisotropy decreases, and the magnetic moment m. Becomes weaker and easier to rotate. As a result, the right-turning nail-shaped domain wall DW apparently moves in the same + x direction as the current I _w , the rear magnetic domain D1 is extended, and the front magnetic domain D2 is shortened. On the contrary, as shown in FIG. 3B, when the current I _w is supplied to the magnetic wire 1 in the −x direction, the electrons e ⁻ having a spin in the + y direction in the vicinity of the interface with the magnetic layer 11 in the channel layer 12 are generated. Unevenly distributed. Since the electron e ^- having a spin in the + y direction rotates the magnetic moment m of the domain wall DW of the magnetic layer 11 clockwise in the xz plane, the domain wall DW apparently moves in the −x direction. That is, the domain wall moves in the current supply direction.

Also in the magnetic thin wire 1 shown in FIG. 4A, similarly to FIG. 3A, when the current I _w is supplied in the + x direction, electrons e ⁻ having a spin in the −y direction are generated near the interface of the stacked channel layers 12. Unevenly distributed. Since the electron e ^- having a spin in the -y direction rotates the magnetic moment m of the domain wall DW counterclockwise, the left-turning nail-shaped domain wall DW apparently rotates in the -x direction opposite to the current I _w . Moving. Then, as shown in FIG. 4B, as in FIG. 3B, when the current I _w is supplied in the −x direction, the electron e ⁻ having a spin in the + y direction rotates the magnetic moment m clockwise. Apparently, the domain wall DW moves in the + x direction. That is, the left-turning nail-shaped domain wall moves in the direction opposite to the current supply direction.

As described above, in the light modulation element 10 according to the present embodiment, the relationship between the supply direction of the current I _w and the movement direction of the domain wall DW is reversed depending on the turning direction of the magnetic moment of the domain wall DW. Further, the magnetic field Hass applied from the nanomagnet 51 depends on the laminated structure (channel layer 12 / magnetic layer 11 / insulator) of the magnetic fine wire 1 and is based on the _{Dzyaloshinskii} -Moriya Interaction (DMI). The magnetic wall is easier to move and the speed is higher when the direction is the same as the effective magnetic field. The effective magnetic field is in the + x direction in a domain wall (up-down domain wall) in which the magnetization direction changes from upward to downward in the + x direction, and in the -x direction in a domain wall (down-up domain wall) in which the magnetization direction changes from downward to upward. , It is preferable that the domain wall DW has a right-turning nail-shaped magnetic structure.

In the light modulation element 10 according to the present embodiment, the domain wall DW is stabilized by the right-turning nail-shaped magnetic structure by the nanomagnet 51 arranged under the magnetic wire 1, so that the current I is always present. Move in the supply direction of _w . Therefore, when the magnetization direction of the magnetic layer 11 in the magnetization reversible region 1 _SW is reversed from the downward state shown in FIG. 2A to the upward state shown in FIG. 2B, the domain wall DW is moved in the −x direction. The electrode 61 is connected to the negative electrode of the current source and the electrode 62 is connected to the positive electrode to supply the current I _w in the −x direction. On the contrary, when the magnetization direction of the magnetization reversible region 1 _SW is reversed from the upward direction shown in FIG. 2B to the downward direction shown in FIG. 2A, the electrode 61 is connected to the positive electrode and the electrode 62 is connected to the negative electrode to generate a current I _w . Supply in the + x direction. In FIGS. 2A and 2B, an arrow indicating the supply direction of the current I _w is attached to the channel layer 12.

Then, as described above, the light reflected by the magnetization reversible region 1 _SW of the magnetic layer 11 has a binary value whose polarization direction is an angle + θ _k / −θ _k rotation (optical rotation) with respect to the incident light depending on the magnetization direction. It becomes one of the lights. Therefore, by setting one of the binary lights to light (white) and the other to dark (black), the light modulation element 10 can be used for the pixels of the reflection type spatial light modulator.

The larger the magnetic field _Hass , the more stable the magnetic structure of the domain wall DW is in the right-turning nail type, and the faster the domain wall moves. Further, the higher the current density of the current I _w , the more electrons e ⁻ having a spin in one direction in the y direction are accumulated at the interface of the channel layer 12 with the magnetic layer 11, and therefore, the temporary coercive force of the magnetic layer 11 is accumulated. Since Hc _f ′ becomes smaller, the movement of the magnetic wall becomes faster. However, if the current density of the current I _w is high, the magnetic thin wire 1 tends to deteriorate. The domain wall moving speed depends on the current density of the current I _w , the _magnitude of the magnetic field _Hass applied to the magnetic layer 11, and the like. The supply time of the current I _w is set so as to be longer than the length in the wire direction. If the length of the magnetization reversible region 1 _SW in the wire direction is about 1 μm, the supply time of the current I _w is about 10 ns, depending on the domain wall moving speed. In order to supply such an extremely short DC current, it is preferable to supply the current I _w as a DC pulse current whose supply time is set to the peak period.

Since the magnetic field _Hass in the −x direction is small or not applied outside the magnetization reversible region 1 _SW of the magnetic layer 11, when the domain wall DW passes through the end of the magnetization reversible region 1 _SW , the magnetic structure of the domain wall DW is changed. It becomes unstable and the domain wall DW becomes immovable even if the supply of the current I _w is continued. Further, as shown in FIGS. 2A and 2B, even if the domain wall DW'at the outer end in the wire direction of the magnetization fixed region 1 _FX2 is generated, the domain wall DW is generated even if the current I _w is flowing for the same reason. ´ does not move. As described above, it is preferable to set the magnitude of the current I _w so that the domain wall DW does not move in the region where the magnetic field _Hass is not applied. Alternatively, even if the domain wall DW can move at a low speed even if the magnetic field _Hass is not applied, the magnetic field −H _pin , + H _pin in the z direction applied from the vicinity of the end of the nanomagnet 51 is the magnetization fixed region 1 _FX1 . , 1 Since _FX2 is fixed in the downward and upward magnetic domains, the domain wall DW does not move into the magnetization fixed regions 1 _FX1 and 1 _FX2 . For that purpose, it is preferable to set the magnitude of the current I _w so that the temporary coercive force Hc _f ′ of the magnetic layer 11 becomes smaller than the H _pin (Hc _f ′ <H _pin ).

As the thickness of the magnetic layer 11 increases, the volume increases at the interface with the channel layer 12 and the magnetic moment m becomes stronger, while the angular momentum of the electrons e ^- in the vicinity of the interface of the channel layer 12 increases. Is constant, so in order to move the domain wall DW by the SOT effect, it is generally necessary to increase the current density of the current I _w . Further, the current I _w is increased in combination with the expansion of the cross-sectional area of the magnetic layer 11. However, in the present embodiment, the nanomagnet 51 aligns the magnetic domain wall DW of the magnetic layer 11 with the right-turning nail-shaped magnetic structure and is stable, so that the current density is low even if the magnetic layer 11 is thick to some extent. It is considered that the magnetic moment can be rotated by.

(Spatial light modulator)
As an example, the light modulation element 10 is mounted as a light modulation element of pixels 9 arranged in the spatial light modulator 90 shown in FIG. In FIG. 5, for the sake of brief explanation, only the magnetic thin wire 1 (represented by the graphic symbol of the resistor) and the electrodes 61 and 62 (represented by the line) of the light modulation element 10 are shown, and four rows are shown. X 16 pixels 9 in 4 rows are shown. The pixel 9 further includes a transistor 71 connected to the electrode 61 of the light modulation element 10 together with the light modulation element 10. The spatial light modulator 90 is similar to the circuit configuration of a selective transistor type MRAM including a 1T1R type memory cell, and includes a word line 84 extending in the column direction and a bit line 81 extending in the row direction. The bit wire 81 is connected to the electrode 61 via the transistor 71, and the word wire 84 is input to the gate of the transistor 71. Further, the electrode 62 is connected to the common potential of all the pixels 9.

The transistor 71 is, for example, a MOSFET (metal oxide semiconductor field effect transistor) and is formed on the surface layer of a Si substrate. Therefore, the pixels 9 can be arranged on the Si substrate as a base. The bit wire 81 and the word wire 84 are made of a metal electrode material like the electrodes 61 and 62. Further, a known inorganic insulating material provided for a semiconductor element such as SiO ₂ or Al ₂ O ₃ is filled in the gap between these wirings or between the magnetic fine wires 1 of the adjacent pixels 9 and 9 respectively. ..

In the spatial light modulator 90, the arrangement direction of the pixels 9 and the wire direction (x direction) of the magnetic wire 1 of the light modulation element 10 do not have to be aligned. For example, in order to increase the aperture ratio of the pixel, the diagonal direction of the array can be designed in the thin line direction so that the length of the magnetic thin line 1 in the thin line direction becomes long. However, the light modulation elements 10 are arranged so that the thin line directions are aligned with all the pixels 9. This is because, in the initial setting process described later, an external magnetic field is applied in the wire direction to align the polarities of the nanomagnets 51 and magnetize them. Further, the layout of the pixel 9 is designed with a space so as not to be magnetically affected by the magnetic fine wire 1 and the nanomagnet 51 of the adjacent pixel 9. Further, it is preferable that the layout is designed so that the arrangement of the magnetization reversible region 1 _SW in the pixel 9 is aligned in all the pixels 9.

(Initial setting process)
The initial setting process of the spatial light modulator will be described. In the initial setting process, the polarity of the nanomagnet 51 of the optical modulation element 10 is magnetized in a predetermined direction, and the magnetic domain of the magnetic layer 11 of the magnetic fine wire 1 is divided only in the fine wire direction, so that the magnetization fixed region 1 _FX1 A down-up domain wall DW is generated at the boundary between these two magnetic domains with the side facing downward and the magnetization fixed region 1 _FX2 side facing upward. The initial setting process can be performed at the time of manufacturing or before using the spatial light modulator 90. First, as a first step, the nanomagnet 51 having the largest coercive force among the magnetic materials of the light modulation element 10 is a bar magnet having an N pole on the + x side and an S pole on the −x side. Therefore, a magnetic field larger than the coercive force of the nanomagnet 51 is applied from the outside in the + x direction.

After stopping the application of the magnetic field in the + x direction, as a second step, two magnetic domains sandwiching the domain wall DW are generated in the magnetic layer 11. Therefore, while applying a magnetic field H _init smaller than the coercive force of the nanomagnet 51 downward (-z direction) from the outside, a current is supplied to the magnetic wire 1 via the electrodes 61 and 62. By generating Joule heat with the current flowing through the magnetic layer 11 and temporarily lowering the coercive force of the magnetic layer 11 to less than H _init and less than H _pin due to the temperature rise, the entire magnetic layer 11 is oriented in the downward magnetization direction. After the single magnetic domain, the application of the magnetic field H _init is stopped, and then the current supply is stopped. In the absence of an external magnetic field, the magnetic layer 11 has a magnetic field in the + z direction + H _pin on the vicinity of the N pole (end on the + x side) due to the nanomagnet 51 arranged below the magnetic layer 11 on the S pole (−x side). A magnetic field in the −z direction −H _pin is applied in the vicinity of the edge). Therefore, by continuing to supply the current even after the application of the magnetic field H _init is stopped, the region including at least the magnetization fixed region 1 _FX2 in the vicinity of the N pole side of the nanomagnet 51 in the magnetic layer 11 is magnetized and inverted. The magnetization direction becomes a magnetic domain in the + z direction. As shown in FIG. 2A, when the magnetization fixed region 1 _FX2 is magnetized inverted, the magnetic layer 11 becomes a magnetic domain in which the magnetization direction is −z direction in the magnetization reversible region 1 _SW and its S pole side, and the magnetization reversible region 1 A down-up domain wall DW is generated at the boundary between the _SW and the magnetization fixed region 1 _FX2 . Further, depending on the current supply direction, the position of the domain wall DW at the boundary between the magnetization reversible region 1 _SW and the magnetization fixed region 1 _FX1 or 1 _FX2 in the magnetic wire 1 of the light modulation element 10 of all the pixels 9. Are aligned. The current can be supplied to the magnetic thin wire 1 in the same manner as the writing method described later.

When the magnetic field −H _pin and + H _pin in the z direction applied from the nanomagnet 51 are larger than the coercive force Hc _f of the magnetic layer 11, the magnetic field H _init (> Hc _f ) is applied in the second step. There is no need to supply current. In the light modulation element 10, the magnetic wire 1 is formed to be longer than the nanomagnet 51 as a connection region with the electrodes 61 and 62, so that it is on the electrode 62 on the N pole side, that is, the magnetization fixed region 1 _FX2 . The magnetic domain in the −z direction may remain on the outside in the thin line direction, but it does not affect the operation of the light modulation element 10 as described above. Further, in the second step of the initial setting process, a magnetic field may be applied upward (+ z direction). In this case, as shown in FIG. 2B, in the magnetic layer 11, the magnetization reversable region 1 _SW and the magnetization fixed region 1 _FX2 on the N pole side thereof are magnetic domains in the + z direction, and the magnetization fixed region 1 _FX1 is a magnetic domain in the −z direction. Therefore, a down-up domain wall DW is generated at the boundary between the magnetization reversible region 1 _SW and the magnetization fixed region 1 _FX1 .

(Writing method)
An example of a method of writing the spatial light modulator 90, that is, setting the magnetization direction in the magnetization reversible region 1 _SW of the magnetic layer 11 upward or downward for each pixel 9 according to a desired light / dark pattern is as follows. Is. Assuming that the potential difference between the bit wire 81 (source of the transistor 71) for supplying the current I _w to the magnetic thin wire 1 and the electrode 62 is V _w , one terminal of the pulse current source is connected to the potential + V _w , and this terminal is connected. The electrodes 62 of all the pixels 9 are connected to. Then, in order to make the magnetization reversible region 1 _SW in the downward magnetization direction (see FIG. 2A), the other terminal of the pulse current source was selected as the potential + 2V _w so as to supply the current I _w in the + x direction. It is connected to the bit line 81 of the row, and the word line 84 of the column of the pixel 9 to be written is connected to the gate power supply. On the contrary, in order to make the magnetization reversible region 1 _SW in the upward magnetization direction (see FIG. 2B), the other terminal of the pulse current source is connected to 0V so as to supply the current I _w in the −x direction. ..

(Modification example)
In the light modulation element 10, the channel layer 12 may be laminated on the upper surface of the magnetic layer 11. In this case, it is preferable to select a material having a relatively high light transmittance or to reduce the thickness of the channel layer 12 so as to sufficiently transmit the light entering and exiting the magnetic layer 11. In such a light modulation element 10, the relationship between the supply direction of the current I _w and the movement direction of the domain wall DW is reversed. Further, the spatial light modulator 90 may connect the source of the transistor 71 of all the pixels 9 to a common potential and connect the electrode 62 to the bit line 81. Further, if the arrangement does not obstruct the light entering and exiting the magnetization reversible region 1 _SW of the magnetic layer 11, the electrode 62 is connected to the upper surface of the magnetic thin wire 1, and the wiring connected to this is connected to the light modulation element 10 (magnetic). It may be arranged above the thin line 1). Alternatively, an integrated transparent electrode covering the entire surface of the spatial light modulator 90 may be provided on the upper side of the light modulation element 10 and the electrode 62 may be connected to the transparent electrode. The transparent electrode can be formed of a known transparent electrode material such as ITO and IZO. By connecting the electrode 62 to the upper surface of the magnetic thin wire 1, that is, by arranging the electrode 62 on the opposite side of the magnetic thin wire 1 of the nanomagnet 51, the nanomagnet is arranged even if it is placed directly above the magnetization fixed region 1 _FX2 of the magnetic layer 11. It does not shield the magnetic field + H _pin applied from the N pole of 51 to the magnetic layer 11. Therefore, the magnetic wire 1 does not have to extend to the outside of the magnetization fixed region 1 _FX2 , and the wire length can be shortened. The electrode 62 is connected to the outside of the boundary with the magnetization reversible region 1 _SW in the magnetization fixed region 1 _FX2 of the magnetic layer 11. Further, when the electrode 62 is connected to the upper surface of the magnetic wire 1 on which the magnetic layer 11 is laminated, a non-magnetic metal material such as Ru, Cu, Au, etc. is used as a protective film for the magnetic layer 11 and the thickness is about 1 to 10 nm. It may be provided with a film of.

The light modulation element 10 may be configured such that the leakage magnetic field in the z direction of the nanomagnet 51 is applied to only one of the magnetization fixed regions 1 _FX1 and 1 _FX2 of the magnetic layer 11. For example, by arranging the S pole side of the nanomagnet 51 close to the electrode 61 so as not to short-circuit it, the magnetic field in the −z direction hardly reaches the magnetic layer 11. However, since the magnetic field + H _pin in the + z direction is applied to the magnetization fixed region 1 _FX2 , the magnetization fixed region 1 _FX2 of the magnetic layer 11 is directed upward after the application of the downward magnetic field H _init is stopped in the second step of the initial setting process. It is possible to generate a domain wall DW by reversing the magnetization. On the other hand, for the magnetization fixed region 1 _FX1 , the magnetic field _Hass in the −x direction may not be applied.

(Magnet Resistive Sensor)
The domain wall moving element according to the first embodiment of the present invention is a magnetoresistive effect element (magnetic storage) by laminating an insulating film and a magnetic anisotropy magnetic film on a magnetization reversible region of a magnetic layer of a magnetic thin wire. Element) can be configured. The configuration of the magnetoresistive sensor will be described in the second embodiment described later.

[Second Embodiment]
The magnetic wall moving element according to the first embodiment is one magnetic field applying member for applying a magnetic field in the thin wire direction to the magnetic layer of the magnetic thin wire, and the magnetization direction is fixed in the magnetization fixing region of the magnetic layer near both ends. However, it is also possible to increase the magnetic field in the vertical direction by adding a magnetic field applying member (secondary magnetic field applying member) to generate a synthetic magnetic field. Hereinafter, the domain wall moving element and the magnetic storage element provided with the domain wall moving element according to the second embodiment of the present invention will be described with reference to FIGS. 6, 7A and 7B. The same elements as those in the first embodiment (see FIGS. 1 to 5) are designated by the same reference numerals, and the description thereof will be omitted.

(Magnet Resistive Sensor)
As shown in FIG. 6, the magnetic resistance effect element (magnetic storage element) 10A according to the second embodiment of the present invention includes a magnetic thin wire 1 in which a magnetic layer 11 and a channel layer 12 are laminated in order from the top, and a magnetic thin wire 1. The nanomagnet (magnetic field applying member) 51, which is arranged on the lower side apart from the channel layer 12 and whose magnetization direction is one direction in the thin wire direction of the magnetic fine wire 1, and the nano magnet 51 are arranged apart from each other in the thin wire direction. Two nanomagnets (secondary magnetic field application members) 52, 52 whose magnetization direction is opposite to that of the nanomagnet 51, which are connected to the lower surface of the magnetic thin wire 1, are laminated on the upper surface of the magnetic layer 11 in the center of the thin wire direction. The barrier layer (insulating film) 3 and the magnetizing fixing layer (reference layer) 43 are provided, and further connected to the electrodes 61 and 62 connected to the lower surfaces of the nanomagnets 52 and 52 and the upper surface of the magnetizing fixing layer 43. The electrode 63 is provided. Therefore, in the magnetoresistive element 10A, the nanomagnet 52 is inserted between the magnetic thin wire 1 and each of the electrodes 61 and 62 with respect to the optical modulation element 10 according to the first embodiment, and further, the magnetic thin wire 1 is further connected. The barrier layer 3, the magnetization fixing layer 43, and the electrode 63 are laminated in this order on the magnetic layer 11. The magnetoresistive element 10A can be a storage element of a memory cell of an MRAM.

The configuration of the magnetic thin wire 1 is as described in the first embodiment. However, in the magnetoresistive element 10A, since the barrier layer 3 and the magnetization fixing layer 43 are laminated on the magnetic layer 11, the channel layer 12 needs to be laminated under the magnetic layer 11. Further, the magnetic layer 11 does not require a magneto-optical effect, and on the other hand, it is preferable that the magnetic layer 11 has a coercive force having a certain magnitude. Further, the magnetic layer 11 may have a thickness and a width of 5 nm or more and a width of 10 nm or more, as long as it has a thickness and a width necessary for maintaining magnetization and resistance to thermal disturbance. Is preferable. Similarly, the magnetization reversible region 1 _SW and the magnetization fixed regions 1 _FX1 and 1 _FX2 on both sides thereof (see FIGS. 7A and 7B) must have a length of 10 nm or more and 1/2 or more of the wire width. preferable. Further, it is preferable that the width of the magnetic layer 11 is 300 nm or less because the magnetic domain is not easily divided in the width direction.

The barrier layer 3 and the magnetization fixing layer 43 constitute a TMR element having a laminated structure of three layers combined with the magnetic layer 11, and the magnetization inversion region 1 _SW of the magnetic layer 11 is read as a readout of the magnetoresistive effect element 10A. It is provided to detect the magnetization direction. That is, the region of the magnetic layer 11 immediately below the magnetization fixing layer 43 becomes the magnetization free layer of the TMR element, and therefore the magnetization fixing layer 43 is arranged so that this region is included in the magnetization reversible region 1 _SW . Ru. Therefore, the magnetization fixed layer 43 is arranged in the magnetization reversible region 1 _SW in the wire direction (x direction), and the length in the wire direction is shorter than that of the magnetization reversible region 1 _SW . The barrier layer 3 and the magnetization fixing layer 43 may have a material and shape suitable for a TMR element together with the magnetic layer 11 immediately below the barrier layer 3 and the magnetization fixing layer 43. In the wire width direction (y direction), the magnetization fixing layer 43 may have a length (width) of 1 or less of the magnetic wire 1 or may be formed large by projecting to the outside of the magnetic wire 1. The magnetization fixing layer 43 is fixed in the magnetization direction upward or downward, and is referred to as upward here. Therefore, it is preferable that the coercive force of the magnetized fixed layer 43 is equal to or higher than the coercive force Hc _f of the magnetic layer 11 and larger than the coercive force Hc _f . Further, the magnetization fixing layer 43 has a structure in which the magnetic force is sufficiently weaker than that of the nano magnet 51 so that the magnetic field generated by the magnetization fixing layer 43 cancels out and weakens the magnetic field _Hass from the nano magnet 51. Therefore, a known perpendicular magnetic anisotropy material can be applied to the magnetization fixing layer 43 as in the magnetic layer 11, and it is particularly used as a magnetization fixing layer (reference layer) of a CPP-GMR element or a TMR element. The material is suitable. Further, it is preferable that the thickness of the magnetization fixing layer 43 is equal to or larger than the thickness of the magnetic layer 11. The barrier layer 3 is an insulating film of a known barrier layer of a TMR element, and it is preferable to apply MgO, and the thickness is preferably less than 3 nm. The barrier layer 3 may be provided at least between the magnetic layer 11 and the magnetization fixing layer 43, and may be provided on the entire upper surface of the magnetic layer 11 also as a protective film. The electrode 63 is made of a metal electrode material like the electrodes 61 and 62.

Like the nano magnet 51, the nano magnet 52 is a very small bar magnet along the wire direction of the magnetic thin wire 1, and has a polarity opposite to that of the nano magnet 51, with the −x side having an N pole. The nanomagnet 52 applies the combined magnetic field with the nanomagnet 51 to the magnetization fixed regions 1 _FX1 and 1 _FX2 of the magnetic layer 11 as magnetic fields −H _pin and + H _pin in the −z direction and + z direction, respectively. In FIG. 6, the lines of magnetic force from the nano magnets 51 and 52 are represented by broken lines. Therefore, the nanomagnets 52 are arranged apart and close to each other on both outer sides of the nanomagnets 51 in the x direction, and the S poles and the N poles face each other directly under the magnetization fixed regions 1 _FX1 and 1 _FX2 of the magnetic layer 11. do. However, the nanomagnet 52 is provided by being connected to the lower surface (channel layer 12) of the magnetic thin wire 1, and the electrodes 61 and 62 are connected to the lower surface of the nanomagnet 52. Therefore, the nanomagnet 52, together with the electrodes 61 and 62, constitutes a supply path of the current I _w to the magnetic wire 1. Therefore, the nano-magnet 52 is arranged so as to be offset above the nano-magnet 51 by the gap between the nano-magnet 51 and the magnetic wire 1, but the nano-magnet 51 and the nano-magnet 52 are at least the nano-magnet 51, It is preferable that the thickness of one of 52 is ½ or more and is arranged so as to face each other. The nanomagnet 52 is made of a hard magnetic material having in-plane magnetic anisotropy, and the same material as the nanomagnet 51 can be selected. The nanomagnet 52 preferably has a magnetic force similar to that of the nanomagnet 51, but may be weaker than the nanomagnet 51 because it is not necessary to apply a leakage magnetic field in the x direction to the magnetic thin wire 1. On the other hand, the nanomagnet 51 and the nanomagnet 52 have different coercive forces so that the polarities can be magnetized in opposite directions. Therefore, for example, the nanomagnet 51 and the nanomagnet 52 have different Co / Pt film thickness ratios of the Co / Pt multilayer films constituting each of them, or have the same width (length in the y direction) and a length in the x direction. The aspect ratio of the plan view shape may be different by making the above different. The two nanomagnets 52, 52 do not have to have the same shape such as the length in the x direction and the coercive force, and both of them may be larger or smaller than the nano magnet 51.

The movement of the magnetic domain wall of the magnetoresistive element 10A according to the present embodiment in the magnetic thin wire due to the current supply is the same as that of the above-described embodiment shown in FIGS. 3A and 3B. The magnetoresistive effect element 10A has a magnetization-fixed layer 43-magnetic layer 11 when the magnetization directions are antiparallel to the magnetization-fixed layer 43 and the magnetic layer 11 in the region immediately below the magnetization-fixed layer 43. High resistance in the direction perpendicular to the membrane surface between them. That is, in the magnetoresistive effect element 10A, when the magnetization direction in the magnetization reversible region 1 _SW of the magnetic layer 11 is downward (see FIG. 7A), the resistance between the electrodes 61 and 63 and between the electrodes 62 and 63 is high. Magnetization reversible region 1 When the magnetization direction of _SW is upward (see FIG. 7B), the resistance is low. Therefore, the magnetoresistive effect element 10A can be used as a storage element of a memory cell of an MRAM by setting, for example, a low resistance state as data “0” and a high resistance state as data “1”.

The magnetoresistive sensor 10A according to the present embodiment has a strong magnetic field −H _pin , + H _pin in the z direction applied to the magnetization fixed regions 1 _FX1 and 1 _FX2 of the magnetic layer 11 due to such a configuration, so that the coercive force is coercive. A magnetic material having a large Hc _f can be applied to the magnetic layer 11. Further, the nanomagnet 52 is connected to the magnetic wire 1 and the electrodes 61 and 62 are arranged under the nanomagnet 52, so that the synthetic magnetic field −H _pin , + H applied from the nanomagnets 51 and 52 to the magnetic layer 11 _{The pin} is not shielded by the electrodes 61, 62.

(Magnetic memory)
As an example, the magnetoresistive effect element 10A is mounted as a magnetoresistive effect element of the memory cells 9A arranged in the magnetic memory 90A shown in FIG. In FIG. 8, 16 memory cells 9A having 4 columns × 4 rows are shown for brief explanation, and for the magnetoresistive effect element 10A, the magnetic wire 1, the barrier layer 3, and the magnetization fixing layer are shown. 43 (with reference numeral 1A) is represented by a combination of the graphic symbols of the resistor and the variable resistor, and the electrodes 61, 62, 63 are represented by lines. The memory cell 9A includes a magnetoresistive effect element 10A, a transistor 71 connected to the electrode 61 of the magnetoresistive effect element 10A, and a diode 72 to which an anode is connected to the electrode 63. The magnetic memory 90A includes a bit line 82 and a word line 84 extending in the column direction, and a source line 81A extending in the row direction, similar to the circuit configuration of a selection transistor type MRAM including a 1T1R type memory cell. Further, a read word line 83 extending in the row direction orthogonal to the bit line 82 is provided. The bit wire 82 is connected to the electrode 62, the source wire 81A is connected to the electrode 61 via the transistor 71, the word wire 84 is input to the gate of the transistor 71, and the read word wire 83 is connected to the electrode via the diode 72. Connect to 63.

Similar to the spatial light modulator 90, the transistor 71 is formed on the surface layer of the Si substrate, and the memory cells 9A can be arranged on the Si substrate as a base. On the other hand, since the diode 72 is provided on the upper side of the magnetic thin wire 1 and the magnetization fixing layer 43, it is formed of polycrystalline silicon (poly-Si) that can be formed at a low temperature of about 150 ° C., although it depends on these materials. It is preferable to be

Similar to the spatial optical modulator 90, in the magnetic memory 90A, the arrangement direction of the memory cell 9A and the thin wire direction (x direction) of the magnetic thin wire 1 of the magnetoresistive sensor 10A do not have to be matched, but the thin wire direction is all the memory. The magnetoresistive effect elements 10A are arranged so as to be aligned in the cell 9A. Further, in the magnetic memory 90A, all the memory cells 9A do not have to have the electrodes 61 and 62 aligned with respect to the polarity of the nanomagnet 51. For example, in each of the magnetic resistance effect elements 10A of two adjacent memory cells 9A, the magnetic thin wire 1 of one of the magnetic resistance effect elements 10A is the magnetization fixed region 1 _FX2 of the magnetic thin wire 1 as shown in FIGS. 7A and 7B. The side may be connected to the electrode 62, and the magnetic wire 1 of the other magnetoresistive sensor 10A may be connected to the electrode 62 on the magnetization fixed region 1 _FX1 side. Here, as an example, as shown in FIG. 9, the memory cells 9A are arranged with the x direction in the magnetoresistive effect element 10A as the column direction in the magnetic memory 90A. Due to such an arrangement, in the magnetoresistive effect elements 10A of the two memory cells 9A and 9A adjacent to each other in the x direction, the electrodes 62 are connected to the common bit wire 82, so that the electrodes 62 are arranged on opposite sides. Then, the electrode 62 and the nanomagnet 52 connected to the electrode 62 can be shared and integrated. In FIG. 9, the electrode 63, the magnetization fixing layer 43, and the barrier layer 3 are omitted, the polarities of the nanomagnets 51 and 52 are indicated by white arrows, and the magnetization directions of the magnetic layer 11 are upward and downward. Is attached.

(Initial setting process)
The initial setting process of the magnetic memory 90A according to the present embodiment can be performed at the time of manufacture or before use, similarly to the spatial light modulator 90. In the present embodiment, in the first step, the nanomagnet 51 and the nanomagnet 52 of the magnetoresistive element 10A are magnetized in opposite polarities. Here, it is assumed that the nanomagnet 52 has a larger coercive force than the nanomagnet 51. First, a magnetic field larger than the coercive force of the nanomagnet 52 is applied from the outside in the −x direction, and the application is stopped with the nanomagnets 51 and 52 as the magnetization direction in the −x direction. Next, a magnetic field larger than the coercive force of the nanomagnet 51 and smaller than the coercive force of the nanomagnet 52 is applied in the + x direction, and only the nanomagnet 51 is magnetized and inverted in the + x direction to stop the application. In the second step, a domain wall DW is generated on the magnetic layer 11 of the magnetic thin wire 1, and the magnetization direction of the magnetization fixing layer 43 is fixed upward. Therefore, a magnetic field _Hinit larger than the coercive force of the magnetization fixing layer 43 is applied upward (+ z direction) to make the magnetization direction of the magnetization fixing layer 43 and the magnetic layer 11 upward. At this time, when the combined magnetic field H _pin of the nanomagnets 51 and 52 is equal to or less than the coercive force Hc _f of the magnetic layer 11 (H _pin ≤ Hc _f ), the magnetic field H _init is applied and the magnetism is magnetic as in the above embodiment. A current is supplied to the thin wire 1 to reduce the coercive force of the magnetic layer 11 to less than H _pin and less than H _init . After the application of the magnetic field H _init is stopped, the magnetic field −H _pin from the nanomagnets 51 and 52 causes the magnetization fixed region 1 _FX1 of the magnetic layer 11 to be magnetization-reversed downward as shown in FIG. 7B, and the magnetization reversible region 1 A down-up domain wall DW is generated at the boundary with the _SW .

The writing of the magnetic memory 90A can be performed in the same manner as the writing of the spatial light modulator 90 including the light modulation element 10 according to the first embodiment. Connect the source wire 81A of the selected (to be written) row to the + (potential + V _w ) terminal of the pulse current source, and connect the bit wire 82 of the column of the selected memory cell 9A to the- (potential 0V) of the pulse current source. In addition to connecting to the terminal of, the word wire 84 in the same row is connected to the gate power supply. As shown in FIG. 7A, data “1” is written in the memory cell 9A (which is an odd number row) including the magnetoresistive effect element 10A to which the electrode 61 is connected to the magnetization fixed region 1 _FX1 side of the magnetic wire 1. On the other hand, data "0" is written in the memory cells 9A (which are even columns) adjacent to each other in the x direction of the memory cells 9A. When writing data by exchanging "1" and "0", the +/- terminals of the pulse current source are exchanged and connected. Further, in writing, it is preferable to connect all the read word lines 83 to the potential + V _w or more so that no current flows through the magnetization fixing layer 43 of the magnetoresistive element 10A.

To read the magnetic memory 90A, all the word lines 84 are connected to 0V, and the transistors 71 of all the memory cells 9A are turned off. Then, the positive pole of the constant current source is connected to the bit wire 82 of the selected memory cell 9A, and the negative pole is connected to the read word wire 83, respectively, and connected in parallel with the constant current source while supplying the constant current _Ir. Measure the resistance value with the voltmeter. The constant current _Ir is set to such a size that the magnetic domain wall DW of the magnetic layer 11 of the magnetoresistive element 10A does not move. Further, in reading, it is preferable to connect the bit wire 82 in the non-selected column to a potential below the − pole of the constant current source and connect the read word wire 83 in the non-selected row to a potential above the + pole.

The magnetoresistive sensor 10A according to the present embodiment may include an intermediate layer having a thickness of 1 to 10 nm made of a non-magnetic metal such as Cu, Ag, and Al, instead of the barrier layer 3. A CPP-GMR element having a three-layer laminated structure in which the intermediate layer, the magnetization fixing layer 43, and the magnetic layer 11 are combined can be configured.

(Light modulation element)
The domain wall moving element according to the second embodiment can be applied to the light modulation element as in the first embodiment. In other words, the light modulation element 10 according to the first embodiment can be provided with the nanomagnet 52. That is, the light modulation element according to the second embodiment has a configuration in which the barrier layer 3, the magnetization fixing layer 43, and the electrode 63 are removed from the magnetoresistive effect element 10A. Further, in the light modulation element according to the second embodiment, the channel layer 12 may be laminated on the magnetic layer 11 as in the first embodiment.

(Modification example)
The magnetoresistive element (magnetic storage element) according to the second embodiment of the present invention may have a structure in which the electrodes are directly connected to the upper surface of the magnetic wire. That is, as shown in FIG. 10, in the magnetoresistive element 10B according to the modified example of the second embodiment of the present invention, the electrodes 61 and 62 are arranged on the opposite sides of the magnetic thin wires 1 of the nanomagnets 51 and 52. Will be done. The electrodes 61 and 62 are connected to the outside of the boundary (see FIGS. 7A and 7B) with the magnetization reversible region 1 _SW in the magnetization fixed regions 1 _FX1 and 1 _FX2 of the magnetic layer 11. In such a magnetoresistive effect element 10B, the nanomagnet 52 does not need to be connected to the magnetic thin wire 1, so that it can be formed at the same height as the nanomagnet 51, and therefore, in the manufacture of the magnetic memory 90A. , The nanomagnet 51 and the nanomagnet 52 can be formed at the same time. In this case, the nanomagnet 51 and the nanomagnet 52 have different coercive forces depending on the aspect ratio of the plan view shape, or ions are injected into only one of them to reduce the coercive force. Further, since the nanomagnet 52 is not electrically connected to the electrodes 61 and 62, the nanomagnet 52 can be shared by the magnetoresistive effect elements 10B adjacent to each other in the x direction regardless of the circuit configuration of the magnetic memory 90A. can. Therefore, in this modification, the memory cells 9A may not be arranged in the x direction, and for example, the diagonal direction of the arrangement of the memory cells 9A may be the x direction. Further, since the electrodes 61 and 62 are arranged on the same side as the barrier layer 3, the magnetization fixing layer 43, and the electrode 63 with respect to the magnetic thin wire 1, the diode 72 can be formed on the surface layer of the Si substrate together with the transistor 71. can. That is, the magnetic memory 90A is provided with a Si substrate on the upper side in FIG. Further, in two memory cells 9A and 9A adjacent to each other in the y direction, the magnetic thin wires 1 may be arranged so as to be close to each other, and the nanomagnets 51 and 52 under the magnetic thin wires 1 may be integrally shared. According to such a configuration, the nano magnets 51 and 52 can be widened to some extent to increase the magnetic force.

The magnetoresistive elements 10A and 10B may be provided with only one nanomagnet 52, that is, only on one end side of the nanomagnet 51. For example, by arranging the nanomagnet 52 only on the S pole side of the nanomagnet 51, a strong synthetic magnetic field −H _pin in the −z direction can be obtained, and an upward magnetic field H _init is applied in the second step of the initial setting process. After stopping, the magnetization fixed region 1 _FX1 of the magnetic layer 11 can be magnetized and inverted downward to generate a down-up domain wall DW. On the other hand, for the magnetization fixed region 1 _FX2 , the magnetic field _Hass in the −x direction may not be applied.

The magnetoresistive effect element (magnetic storage element) according to the modified example of the second embodiment of the present invention has a structure in which a magnetic field applying member and nanomagnets constituting a submagnetic field applying member are integrated in a magnetic memory in which the elements are arranged. can do. That is, as shown in FIG. 11, the magnetic resistance effect element 10C according to another modification of the second embodiment of the present invention includes one nanomagnet 51a or nanomagnet 51b, and also includes the magnetic resistance effect element 10C. In the magnetic memory 90A provided in the memory cell 9A, the magnetic resistance effect elements 10C are arranged in the wire direction of the magnetic thin wire 1, and the nanomagnets (magnetic field application members) 51a and 51b of the two adjacent magnetic resistance effect elements 10C and 10C are arranged. , Are fixed in opposite polarities.

In the magnetic memory 90A in which the magnetic resistance effect element 10C according to the present modification is arranged, the magnetic resistance effect element 10B (see FIG. 10) according to the modification is the same as the magnetic resistance effect element 10B (see FIG. 10). Arranged in. The nano-magnet 51a and the nano-magnet 51b have the same configuration as the nano-magnet 51 of the first embodiment, but the polarities are opposite to each other, the nano-magnet 51a has the + x side as the N pole, and the nano-magnet 51b is −. Let the x side be the north pole. Therefore, in the magnetoresistive element 10C provided with the nanomagnet 51b, the magnetic field _Hass is applied to the magnetic layer 11 in the + x direction. Along with this, the arrangements of the electrodes 61 and 62 have been exchanged. That is, the magnetoresistive effect elements 10C adjacent to each other in the x direction have a configuration in which they are inverted in the x direction. Further, the nanomagnets 51a and the nanomagnets 51b have different coercive forces like the nanomagnets 51 and the nanomagnets 52 of the second embodiment so that the polarities can be magnetized in opposite directions. However, it is preferable that the magnetic fields _{Hass in the −x direction and the + x direction have the same strength, and the nanomagnets} 51a and the nanomagnets 51b are made of materials and shapes (width, thickness) so that the magnetic forces are about the same. S) is selected and designed.

The nanomagnets 51a and the nanomagnets 51b are preferably arranged apart and close to each other in the same manner as the nanomagnets 51 and the nanomagnets 52 of the magnetoresistive elements 10A and 10B, and the S poles and the N poles face each other. .. Therefore, the magnetic fine wires 1 of the magnetoresistive effect elements 10C adjacent to each other in the x direction and the electrodes 61 and 62 connected to the upper surface thereof are arranged close to each other so as not to cause a short circuit. With such a configuration, in the magnetoresistive effect element 10C provided with the nanomagnet 51a, the combined magnetic field with the nanomagnet 51b of the magnetoresistive effect element 10C on both sides thereof is the magnetic field −H _pin , + H _pin in the −z direction and the + z direction. As a result, it is applied to the magnetization fixed regions 1 _FX1 and 1 _FX2 of the magnetic layer 11, respectively. The same applies to the magnetoresistive element 10C provided with the nanomagnet 51b. Further, when the memory cells 9A are arranged in the x direction, the electrodes 62 of the two adjacent magnetoresistive elements 10C and 10C can be shared and integrated.

Since the magnetoresistive effect elements 10A, 10B, and 10C according to the second embodiment and its modifications have strong magnetic fields −H _pin and + H _pin in the z direction, a magnetic material having a large coercive force Hc _f is applied to the magnetic layer 11. At the same time, the magnetization directions of the magnetization fixing regions 1 _FX1 and 1 _FX2 can be easily fixed downward and upward. As a result, in the initial setting process, a down-up domain wall DW is more reliably generated in one place in the application region of the magnetic field _Hass from the nanomagnet 51 of the magnetic layer 11 (magnetization reversible region 1 _SW ). Can be done. Further, the magnetoresistive effect element 10C can miniaturize the memory cell 9A including the magnetoresistive sensor 10C.

[Third Embodiment]
The domain wall moving element and the magnetic storage element provided with the magnetic wall moving element do not rely on the leakage magnetic field of the nanomagnet 51 or the nanomagnets 51, 52 to fix the magnetization direction in the magnetization fixing regions 1 _FX1 and 1 _FX2 of the magnetic layer 11 of the magnetic wire 1. It can also be configured. Hereinafter, the domain wall moving element and the magnetic storage element provided with the domain wall moving element according to the third embodiment of the present invention will be described with reference to FIGS. 12A and 12B. The same elements as those of the first and second embodiments and their modifications (see FIGS. 1 to 11) are designated by the same reference numerals, and the description thereof will be omitted.

(Magnet Resistive Sensor)
The magnetoresistive effect element (magnetic storage element) 10D according to the third embodiment of the present invention stores the memory cell of the MRAM, similarly to the magnetoresistive effect elements 10A, 10B, 10C according to the second embodiment and its modifications. It is an element. As shown in FIGS. 12A and 12B, the magnetic resistance effect element 10D is separated from the magnetic thin wire 1 in which the magnetic layer 11 and the channel layer 12 are laminated in order from the top, and the channel layer 12 below the magnetic thin wire 1. Arranged nanomagnets (magnetic field application member) 51 in one direction in the thin wire direction of the magnetic thin wire 1 and the barrier layer (insulating film) 3 laminated on the upper surface in the center of the thin wire direction of the magnetic layer 11 and magnetization fixing. A layer (reference layer) 43 is provided, and further, on the upper surfaces of the magnetization fixing layers 41, 42 and the magnetization fixing layers 41, 42, 43 laminated on the upper surfaces of the magnetic layer 11 in the vicinity of both ends in the wire direction. It includes electrodes 61, 62, 63 to be connected. Therefore, in the magnetoresistive effect element 10D, the magnetization fixing layers 41 and 42 are laminated on both ends of the upper surface of the magnetic layer 11 of the magnetic thin wire 1 in the thin wire direction with respect to the optical modulation element 10 according to the first embodiment, respectively, and the electrode 61 is provided. , 62 are rearranged and connected to the upper surface of the magnetic thin wire 1 via the magnetization fixing layers 41 and 42, and further, the barrier layer 3, the magnetization fixing layer 43, and the electrode 63 are connected at the center of the upper surface of the magnetic layer 11 in the thin wire direction. It is a structure in which they are stacked in order.

One of the magnetization fixing layers 41 and 42 is fixed upward in the magnetization direction and the other downward, and the magnetic layers are laminated on the magnetization fixing regions 1 _FX1 and 1 _FX2 of the magnetic layer 11 of the magnetic thin wire 1. It is magnetically coupled to this region of 11 to fix the magnetization direction in this region to the same magnetization direction as the magnetization fixing layers 41 and 42. Therefore, the magnetization fixing layers 41 and 42 are made of a vertically magnetic anisotropy material like the magnetization fixing layer 43, and the coercive force is at least larger than the coercive force Hc _f of the magnetic layer 11. Specifically, even if the coercive force of the magnetized fixed layers 41 and 42 temporarily decreases due to the current I _w flowing through the electrodes 61 and 62 when the current I _w is supplied to the magnetic wire 1. , It follows the magnetic layer 11 and prevents the magnetization from being reversed. Further, since the magnetization fixing layer 41 and the magnetization fixing layer 42 are fixed in the magnetization directions opposite to each other, it is preferable that the coercive force is different from each other. Further, since the magnetic fields −H _pin and + H _pin in the z direction are applied from the nanomagnet 51 to the magnetization fixed regions 1 _FX1 and 1 _FX2 , respectively, it is preferable to match the magnetization directions of the magnetization fixed layers 41 and 42 with this. Therefore, the magnetization fixing layer 41 is fixed in the downward magnetization direction, and the magnetization fixing layer 42 is fixed in the upward magnetization direction. The magnetization fixing layer 41 has a coercive force different from that of the magnetization fixing layer 43 because it is fixed in the magnetization direction opposite to that of the magnetization fixing layer 43, while the magnetization fixing layer 42 has the same coercive force as the magnetization fixing layer 43. can do. Further, the magnetoresistive element 10D may be provided with a magnetic bonding film having a thickness of about 1 to 10 nm made of a non-magnetic metal such as Ru or Ta at the interface between the magnetic layer 11 and the magnetization fixing layers 41 and 42, respectively. good.

(Initial setting process)
The initial setting process of the magnetoresistive effect element 10D according to the present embodiment is the same as in the first and second embodiments and the modified examples thereof, with respect to the magnetic memory 90A provided with the magnetoresistive effect element 10D in the memory cell 9A. Performed at the time of manufacture or prior to use. In the present embodiment, after applying an external magnetic field in the + x direction to magnetize the nanomagnet 51 in the first step, a magnetic domain wall DW is generated and magnetized in the magnetic layer 11 of the magnetic fine wire 1 in the second step. The fixed layer 41 and the magnetized fixed layers 42 and 43 are fixed in the magnetization directions opposite to each other. Here, it is assumed that the magnetized fixed layers 42 and 43 have a larger coercive force than the magnetized fixed layer 41. After the first step, a magnetic field _Hinit larger than all the coercive forces of the magnetization fixing layers 41, 42, 43 and the magnetic layer 11 is applied upward (+ z direction) from the outside, and these are set as the upward magnetization directions. Stop the application. Next, a magnetic field H _init ′, which is larger than the coercive force of the magnetization fixing layer 41 and the magnetic layer 11 and smaller than the coercive force of the magnetization fixing layers 42 and 43, is applied downward (−z direction) to apply the magnetization fixing layer 41. , And the region other than the magnetization fixed region 1 _FX2 of the magnetic layer 11 is magnetized inverted downward to stop the application. Since the magnetization-fixed region 1 _FX2 of the magnetic layer 11 is magnetically coupled to the magnetization-fixed layer 42, as shown in FIG. 12A, the magnetization directions remain fixed in the same upward direction, and the magnetization of the magnetic layer 11 is reversed. A domain wall DW is generated at the boundary between the possible region 1 _SW and the magnetization fixed region 1 _FX2 . Alternatively, the coercive force of the magnetization fixing layers 41 and 42 (and the magnetization fixing layer 43) may be the same. In the second step, a current is supplied to the magnetic thin wire 1 and the magnetization fixed layers 41 and 42 via the electrodes 61 and 62 while applying the magnetic field H _init in the + z direction. After the magnetic layer 11 and the magnetization fixing layers 41, 42, and 43 are set as the upward magnetization directions, the application of the magnetic field H _init is stopped, and then the current supply is stopped. As described in the first embodiment, in the absence of an external magnetic field, a magnetic field in the −z direction is applied near the S pole (end on the −x side) of the nanomagnet 51. The magnetic field applied to the magnetized fixed layer 41 is weaker than the magnetic field −H _pin in the magnetic layer 11, but due to the fact that a current is supplied, the magnetized fixed layer 41 has a coercive magnetic force as the temperature rises, similar to the magnetic layer 11. Is temporarily reduced, so that the magnetization is inverted downward together with the magnetization fixed region 1 _FX1 of the magnetic layer 11 (see FIG. 12B). Therefore, the current supplied in the second step is preferably large enough to sufficiently reduce the coercive force of the magnetization fixing layer 41, and is larger than the current I _w at the time of writing.

The movement of the magnetic domain wall of the magnetoresistive element 10D according to the present embodiment in the magnetic thin wire by the current supply is the same as that of the first embodiment shown in FIGS. 3A and 3B. Further, writing and reading of the magnetic memory 90A having the magnetoresistive element 10D provided in the memory cell 9A can be performed in the same manner as that provided with the magnetoresistive element 10A. In the magnetoresistive effect element 10D, since the magnetization directions of the magnetization fixed regions 1 _FX1 and 1 _FX2 of the magnetic layer 11 are fixed by the magnetization fixing layers 41 and 42, it is assumed that the domain wall DW can move only by supplying the current I _w . However, it does not move out of the magnetization reversible region 1 _SW .

The magnetoresistive sensor 10D according to the third embodiment is provided with only one nanomagnet 51 made of a hard magnetic material by such a configuration, and the magnetization directions of the magnetization fixed regions 1 _FX1 and 1 _FX2 of the magnetic layer 11 are set. It can be easily and stably fixed downward and upward. Further, in the magnetoresistive effect element 10D, similarly to the magnetoresistive effect elements 10B and 10C, the barrier layer 3, the magnetization fixing layer 43, and the electrodes 61 and 62 are arranged on the same side as the electrode 63 with respect to the magnetic wire 1. Therefore, the diode 72 can be formed on the surface layer of the Si substrate together with the transistor 71.

In the magnetic resistance effect element 10D, the coercive force of the magnetization fixing layers 41 and 42 is sufficiently increased so that the direction of the leakage magnetic field of the nanomagnet 51 applied to the magnetization fixing regions 1 _FX1 and 1 _FX2 of the magnetic layer 11 (-). Regardless of (z direction, + z direction), the magnetization fixing regions 1 _FX1 and 1 _FX2 can be fixed in a desired magnetization direction only by the magnetization fixing layers 41 and 42. Therefore, the magnetization directions of the magnetization fixing layers 41 and 42 can be exchanged to form the domain wall DW into a left-turning nail-type magnetic structure. Further, the magnetoresistive element 10D can form the x-direction length of the nanomagnet 51 longer than the fine wire length of the magnetic thin wire 1 by sufficiently increasing the coercive force of the magnetization fixing layers 41 and 42. Even if the magnetic field _Hass is applied from the nanomagnet 51 having such a shape to the magnetization fixed regions 1 _FX1 and 1 _FX2 of the magnetic layer 11, the magnetization directions of these regions 1 _FX1 and 1 _FX2 are the magnetization fixed regions 41, It is strongly fixed by 42, and the domain wall DW does not enter when the current I _w is supplied. Therefore, for example, the nano magnet 51 can be formed into the same plan view shape as the magnetic thin wire 1, and the nano magnet 51 and the magnetic thin wire 1 can be processed at the same time in the production of the magnetic memory 90A. Alternatively, the nanomagnet 51 can be formed to have a length in the x direction longer than that of the magnetic wire 1, and further, one nanomagnet 51 is used in the magnetoresistive effect element 10D of two or more memory cells 9A adjacent to each other in the x direction. Can be shared.

[Fourth Embodiment]
In the domain wall moving element and the magnetic storage element provided with the domain wall moving element according to the second embodiment of the present invention, the submagnetic field application member may be a vertical bar magnet made of a hard magnetic material having vertical magnetic anisotropy. Hereinafter, the domain wall moving element according to the fourth embodiment of the present invention will be described with reference to FIG. The same elements as those of the first and second embodiments and their modifications (see FIGS. 1 to 11) are designated by the same reference numerals, and the description thereof will be omitted.

(Light modulation element)
The light modulation element (domain wall moving element) 10E according to the fourth embodiment of the present invention is used for the pixels of the spatial light modulator, similarly to the light modulation element 10 according to the first embodiment. As shown in FIG. 13, the optical modulation element 10E is arranged so that the magnetic thin wire 1 in which the magnetic layer 11 and the channel layer 12 are laminated in order from the top and the magnetic thin wire 1 are arranged below the magnetic thin wire 1 so as to be separated from the channel layer 12. The magnetizing direction is one direction of the thin wire direction of the magnetic thin wire 1. The nano magnet (magnetic field application member) 51 and the nano magnet 51 are arranged apart from each other on both sides of the thin wire direction and connected to the lower surface of the magnetic thin wire 1, and the magnetization direction is downward. , And upward nanomagnets (secondary magnetic field applying member) 53a, 53b, and further includes electrodes 61, 62 connected to the lower surfaces of the nano magnets 53a, 53b, respectively. Therefore, the light modulation element 10E has a configuration in which the nanomagnets 52 and 52 of the domain wall moving element (see FIG. 6) according to the second embodiment are replaced with nanomagnets 53a and 53b.

The nano magnet 53a and the nano magnet 53b are extremely small bar magnets along the z direction, and the polarity on the side facing the magnetic wire 1 (upper side) is the same as that on the opposite side of the nano magnet 51, that is, −x. The nanomagnet 53a on the side has an S pole on the upper side, and the nanomagnet 53b on the + x side has an N pole on the upper side. The nanomagnet 53a applies its own leakage magnetic field or a combined magnetic field with the nanomagnet 51 to the magnetization fixed region 1 _FX1 of the magnetic layer 11 as a magnetic field −H _pin in the −z direction. The nanomagnet 53b applies its own leakage magnetic field or a combined magnetic field with the nanomagnet 51 to the magnetization fixed region 1 _FX2 of the magnetic layer 11 as a magnetic field in the + z direction + H _pin . In FIG. 13, the lines of magnetic force from the nano magnets 51 and the nano magnets 53a and 53b are represented by broken lines. Therefore, the nano-magnets 53a and 53b are arranged apart and close to each other on both outer sides of the nano-magnet 51 in the x-direction, and face the nano-magnet 51 directly under the magnetization fixing regions 1 _FX1 and 1 _FX2 of the magnetic layer 11. Further, the nano magnets 53a and 53b are provided by being connected to the lower surface (channel layer 12) of the magnetic thin wire 1, and the electrodes 61 and 62 are connected to the lower surfaces of the nano magnets 53a and 53b. Therefore, the nanomagnets 53a and 53b together with the electrodes 61 and 62 form a supply path of the current I _w to the magnetic wire 1. Further, it is preferable that the nano-magnets 53a and 53b are arranged so that the lower end, which is different from the opposite nano-magnet 51, is below the nano-magnet 51. The nanomagnets 53a and 53b have a magnetic force such that the leakage magnetic field alone or the combined magnetic field with the nanomagnet 51 is sufficiently large as −H _pin and + H _pin (H _pin > Hc _f ′). .. Therefore, the nanomagnet 53a and the nanomagnet 53b are made of a hard magnetic material having vertical magnetic anisotropy, and for example, a transition metal such as Fe, Co, Ni and a noble metal such as Pd, Pt are mixed in a film thickness ratio of 1. : A multilayer film such as a Co / Pd multilayer film laminated alternately and repeatedly at about 2 to 4 is applied. Further, it is preferable that the nanomagnet 53a and the nanomagnet 53b have different coercive forces so that the polarities can be magnetized in opposite directions, and the coercive force is both smaller or larger than that of the nanomagnet 51. .. Therefore, for example, the nanomagnets 53a and the nanomagnets 53b have different aspect ratios in a plan view shape.

(Initial setting process)
Similar to the first and second embodiments and variations thereof, the initial setting process of the light modulation element 10E according to the present embodiment is performed at the time of manufacturing the spatial light modulator 90 having the light modulation element 10E in the pixels. Or done before use. Here, in the light modulation element 10E, the coercive force of the nano magnet 53a is larger than that of the nano magnet 53b, and both the nano magnets 53a and 53b are smaller than the nano magnet 51. Therefore, as in the first embodiment, first, in the first step, an external magnetic field is applied in the + x direction to magnetize the polarity of the nanomagnet 51. Then, in the second step, a magnetic field H _init larger than all the coercive forces of the nanomagnets 53a, 53b and the magnetic layer 11 from the outside while supplying a current to the magnetic wire 1 and the nanomagnets 53a, 53b as needed. Is applied downward (−z direction), and the application of the magnetic field H _init is stopped with these as the downward magnetization direction. Next, a magnetic field H _init ′, which is larger than the coercive force of the nanomagnet 53b and the magnetic layer 11 and smaller than the coercive force of the nanomagnet 53a, is applied upward (+ z direction) to turn the nanomagnet 53b and the magnetic layer 11 upward. The magnetism is reversed to stop the application of the magnetic field H _init ′, and then the current supply is stopped. After the external magnetic field (magnetic field H _init ′) is stopped, the magnetization fixed region 1 _FX1 of the magnetic layer 11 is magnetized and inverted downward by the magnetic field −H _pin .

The domain wall movement of the light modulation element 10E according to the present embodiment in the magnetic fine wire due to the current supply is the same as that of the first embodiment shown in FIGS. 3A and 3B. Further, the writing of the spatial light modulator 90 provided with the light modulation element 10E in the pixel can be performed in the same manner as that provided with the light modulation element 10.

Like the magnetoresistive effect element 10A according to the second embodiment, the optical modulation element 10E according to the fourth embodiment has a strong magnetic field −H _pin and + H _pin in the z direction, so that a magnetic material having a large coercive force Hc _f is used. While being applied to the magnetic layer 11, the magnetization directions of the magnetization fixing regions 1 _FX1 and 1 _FX2 can be easily fixed downward and upward. The light modulation element 10E may be configured to include only one of the nanomagnets 53a and 53b. For example, when only the nanomagnet 53a is provided, the initial setting process is larger than the coercive force of the magnetic layer 11 and the coercive force of the nanomagnet 53a after applying the magnetic field _Hinit in the −z direction as described above. A magnetic field smaller than that may be applied in the + z direction.

(Magnet Resistive Sensor)
Similar to the second embodiment (see FIG. 6), the domain wall moving element according to the fourth embodiment of the present invention has a barrier layer (insulating film) 3 on the magnetization reversible region 1 _SW of the magnetic layer 11 of the magnetic wire 1. By stacking the magnetization fixing layer (reference layer) 43 and the magnetization fixed layer (reference layer) 43, a magnetoresistive effect element (magnetic storage element) can be configured. Further, in the magnetoresistive sensor, the electrodes 61 and 62 may be connected to the upper surface of the magnetic thin wire 1, and in this case, the nanomagnets 53a and 53b are connected to the magnetic thin wire 1 as in the nanomagnet 51. It may be separated.

As described above, according to the domain wall moving element and the magnetic storage element provided with the domain wall moving element according to the embodiment of the present invention and its modified example, the writing speed is increased without increasing the current by incorporating the nanomagnet. Therefore, the magnetic fine wire does not easily deteriorate and can be used for a long period of time. Moreover, since the circuit configuration is not complicated, the pixels and memory cells do not become large.

In order to confirm the effect of the present invention, a sample simulating the domain wall moving element according to the embodiment of the present invention was prepared, and the moving speed of the domain wall was measured. In this embodiment, a magnetic field is applied from the outside instead of the leakage magnetic field of the nanomagnet of the domain wall moving element. Therefore, as shown in FIG. 14, the sample is limited to the magnetic wire and a pair of electrodes connected to the upper surface thereof, and further, in order to generate a domain wall dividing in the wire direction, the sample is placed on one end side of the magnetic wire in the direction perpendicular to the film surface. As the nanomagnet of the above, a hard magnetic material having vertical magnetic anisotropy was provided.

(Sample preparation)
The magnetic thin wire has a laminated structure of base film: SiN (5 nm) / channel layer: Ta (3 nm) / magnetic layer: GdFe (10 nm) / protective film: SiN (5 nm), and is formed in a linear shape with a width of 0.5 μm. .. The composition of GdFe was Gd: 22.6 at% and Fe: 77.4 at%. The hard magnetic material has a laminated structure of Ru (3 nm) / Pt (3 nm) / [Co (0.3 nm) / Pd (0.6 nm)] × 25 / Ru (3 nm) with a total thickness of 31.5 nm. , 0.5 μm (length in the thin line direction) × 3 μm. First, a SiN film was formed on the Si substrate on which the thermal oxide SiO ₂ was formed on the surface to form a trench, and a laminated film constituting a hard magnetic material was formed and embedded. A laminated film constituting the magnetic fine wire was formed on the film and formed into a linear shape, and SiN was further embedded around the magnetic fine wire. The hard magnetic material and the magnetic thin wire were each formed by magnetron sputtering, and formed by electron beam lithography, ion milling, and lift-off. Then, a part (two places) of the protective film on the surface of the magnetic fine wire was removed to form an electrode with Ag. The distance between the electrodes (length in the thin line direction) is 17 μm. Further, the distance between the electrode on the + x side and the hard magnetic material in the wire line direction is 1 to 2 μm. Further, as a comparative example, a sample without a channel layer (Ta film) was prepared in which the magnetic thin wire had a laminated structure of a base film: SiN (5 nm) / a magnetic layer: GdFe (15 nm) / a protective film: SiN (5 nm). (The composition of GdFe is Gd: 23.5 at%, Fe: 76.5 at%).

(Measurement of coercive force)
A magnetic field of 800 mT (+ 800 mT) was applied upward from the lower side to each sample of the example and the comparative example, and the magnetic layer of the magnetic fine wire and the hard magnetic material were set to the upward magnetization direction. Next, the car rotation angle was measured using focused laser light (wavelength: 658 nm, laser spot size: 2 to 3 μm), and the magnetization reversal of the magnetic layer of the magnetic fine wire and the hard magnetic material was observed. While measuring the direction of polarization of the reflected light from the sample (car rotation angle) with a micro Kerr measuring device, apply an applied magnetic field while gradually increasing its magnitude (absolute value), and observe the change in the direction of polarization. did. The coercive force of the hard magnetic material was about 400 mT. Further, FIGS. 15A and 15B show the hysteresis loop of the car rotation angle when the applied magnetic field is changed to ± 200 mT in the magnetic thin wire of each sample of the example and the comparative example. The coercive force of the magnetic thin wire of the sample of the example was about 40 mT for both + and-. On the other hand, the coercive force of the magnetic thin wire of the sample of the comparative example was about +50 mT and about -30 mT.

(Initial setting process)
While applying a magnetic field of + 800 mT to the sample, a DC pulse current with a pulse width of 50 ns and 2.2 mA was supplied to the magnetic thin wire through the electrode, and the magnetic layer and the hard magnetic material of the magnetic thin wire were set to the upward magnetization direction. By stopping the application of the magnetic field, an up-down magnetic wall was generated in the vicinity of the hard magnetic material of the magnetic layer, and a pulse current having a pulse width of 15 ns was further supplied to move the magnetic wall to a predetermined position.

(Measurement of domain wall moving speed)
A pulse current having a pulse width of 15 ns was supplied to the magnetic thin wire while applying a magnetic field of a certain magnitude from the outside in the thin wire direction. Before and after the current supply, observe the position of the magnetic domain wall of the magnetic thin wire, measure the distance and direction of the magnetic wall moving from the MO difference image, and calculate the distance per unit time from the total current supply time (15ns x number of pulses). Calculated as the moving speed. While applying a magnetic field of 25 mT, 0.4, 0.6, 0.8, 1.0, 1.4, 1.8, 2.2 mA (the sample of the comparative example is 1.8, 2.0, A current of 2.2 mA) was supplied. In addition, a (0T) current was supplied to the sample of the example without applying a magnetic field, simulating a comparative example without a nanomagnet. Further, for the sample of the example, a magnetic field of 4,8,12,25 mT was applied when a current of 2.2 mA was supplied. These magnetic field application and current supply were performed by changing the directions in the + x direction and the −x direction, respectively. Further, for the sample of the example, an external magnetic field was applied downward in the initial setting process to generate a down-up domain wall, and the same measurement was performed.

Each measurement was performed 5 times and the mean and standard deviation were calculated. 16A and 16B show graphs of the current density (J) dependence of the domain wall moving speed (ν) according to the sample of the example. 17A and 17B show graphs of the magnetic field (H) dependence of the domain wall moving velocity (ν) according to the sample of the example. 16A and 17A are samples in which an up-down domain wall is generated, and FIGS. 16B and 17B are samples in which a down-down domain wall is generated. Also, in the plot area of these graphs, an arrow that simply indicates the magnetization direction of the domain wall is shown. Further, FIG. 18 shows a graph of the current density (J) dependence of the domain wall moving speed (ν) between the sample of the comparative example and the sample of the example in which no magnetic field is applied. The domain wall moving speed is expressed as positive when the domain wall moves in the + x direction and as negative when the domain wall moves in the −x direction.

As shown in FIGS. 16A and 16B, the magnetic domain wall of the magnetic thin wire sample in which the channel layer is laminated moves due to the current supply in the thin wire direction to the magnetic thin wire, and the higher the current density, the higher the moving speed tends to be. Observed. The state in which no magnetic field is applied (H = 0T) is shown in an enlarged manner in FIG. Further, by applying a magnetic field in the wire direction together with the current supply, the moving speed of the domain wall becomes high, and as shown in FIGS. 17A and 17B, it is particularly remarkable at an absolute value of 8 mT or more, and the larger the magnetic field, the faster the moving speed. Became faster. As shown in FIG. 18, the domain wall moves only by supplying a current even if a magnetic field is not applied, but the maximum moving speed is 10.5 m / s, and a current of 2.15 × 10 ¹¹ A / m ² is applied. The peak was when it was supplied. On the other hand, when a magnetic field of 25 mT is applied, the moving direction becomes stable when the current density is 1.23 to 2.15 × 10 ¹¹ A / m ² or more, and the current density is increased to 3.38 × 10 ¹¹ A / m ² . However, the moving speed of the magnetic wall increased with the current density, and became more than 20 times faster than when no magnetic field was applied. Moreover, even when a magnetic field of 8 mT was applied, the speed was about 10 times faster.

The up-down magnetic walls of FIGS. 16A and 17A have a magnetic field applied in the + x direction (FIG. 16A: ● (black circle), FIG. 17A: right half of the plot area) and a right-turning nail-shaped magnetic structure. Therefore, when the magnetism moves in the same direction as the current supply direction and the magnetic field is applied in the −x direction (Fig. 16A: ○ (white circle), Fig. 17A: left half of the plot area), it is a left-turning nail-type magnetism. Since it has a structure, it moved in the direction opposite to the current supply direction. On the other hand, the down-up magnetic wall of FIGS. 16B and 17B has a left-turning nail-shaped magnetic structure when a magnetic field is applied in the + x direction (FIG. 16B: ● (black circle), FIG. 17B: right half of the plot area). (See FIGS. 4A and 4B), so that the current moves in the opposite direction of the current supply direction and the magnetic field is applied in the −x direction (FIG. 16B: ○ (white circle), FIG. 17B: left half of the plot area). Since it has a right-turning nail-type magnetic structure (see FIGS. 3A and 3B), it moved in the same direction as the current supply direction. Further, when no magnetic field was applied, both the up-down domain wall and the down-up domain wall moved in the same direction as the current supply direction, as shown in FIG. Further, when the magnetic field had an absolute value of 12 mT or less, the moving speed of the domain wall having a right-turning nail-type magnetic structure was faster than that of the left-turning. It is considered that this is because the applied magnetic field has the same direction as the effective magnetic field by DMI. On the other hand, when the applied magnetic field is 25 mT, there is no significant difference in the moving speed, which is considered to be due to the applied magnetic field being sufficiently stronger than the effective magnetic field.

As shown in FIG. 18, in the sample of the comparative example without the channel layer (without Ta film), the domain wall moved in the direction opposite to the current supply direction even when no magnetic field was applied, but the channel layers were laminated. It was slower than the sample of the example given, and when a magnetic field was applied, the moving speed was further reduced, and there was almost no movement.

As described above, the magnetic domain wall can be moved at high speed with a small current by providing the magnetic fine wire by stacking the channel layers and applying a magnetic field in one direction in the thin wire direction. The effect is obtained when the applied magnetic field is 8 mT or more, and such a magnetic field is a leakage magnetic field from a nanomagnet made of a hard magnetic material having a planoscopic size similar to that of the magnetic fine wire, which is formed in a pixel or a memory cell together with the magnetic fine wire. Is enough. Furthermore, it was confirmed that a high effect can be obtained even with a relatively thick and wide magnetic thin wire having a thickness of 10 nm and a width of 500 nm.

Although the embodiments for implementing the domain wall moving element and the magnetic storage element provided with the domain wall moving element, and the magnetic memory and the spatial light modulator according to the present invention have been described above, the present invention is limited to these embodiments. It is not a thing, and various changes can be made within the range shown in the claim.

10,10E Light modulation element (domain wall moving element)
10A, 10B, 10C, 10D Magnetoresistive element (magnetic storage element)
1 Magnetic wire 11 Magnetic layer 12 Channel layer 3 Barrier layer (insulating film)
41, 42 Magnetized fixed layer 43 Magnetized fixed layer (reference layer)
51 Nano magnet (magnetic field application member)
51a, 51b Nano magnet (magnetic field application member)
52 Nano magnet (secondary magnetic field application member)
53a, 53b Nano magnet (secondary magnetic field application member)
61, 62 Electrode 63 Electrode 90 Spatial Light Modulator 90A Magnetic Memory 9 Pixel 9A Memory Cell

Claims (9)

A magnetic thin wire formed by laminating a magnetic layer made of a vertically magnetic anisotropy material and a channel layer having a spin hole effect to form a fine wire, and an in-plane magnetic anisotropy arranged below the magnetic fine wire. With a magnetic field application member made of hard magnetic material,
In the magnetic field applying member, the magnetization direction is fixed in a predetermined direction in the thin wire direction of the magnetic thin wire, and the generated magnetic field is applied to the magnetic thin wire.
A magnetic domain wall moving element characterized in that when a current is supplied to the magnetic thin wire in the thin wire direction, the magnetic domain wall generated in the magnetic layer moves in a direction corresponding to the current supply direction in the thin wire direction. The magnetic domain wall moving element according to claim 1, wherein the magnetic fine wire extends to the outside of one or both of the thin wire directions with respect to the magnetic field applying member. A sub-magnetic field applying member made of a hard magnetic material having in-plane magnetic anisotropy is further provided on one side or both sides of the magnetic field applying member in the wire direction of the magnetic wire.
The magnetizing direction of the sub-magnetic field applying member is fixed in the direction opposite to that of the magnetic field applying member.
The domain wall moving element according to claim 2, wherein a magnetic field obtained by combining magnetic fields generated by the magnetic field applying member and the submagnetic field applying member is applied to the magnetic fine wire. A submagnetic field application member made of a hard magnetic material having vertical magnetic anisotropy is further provided on one side or both sides of the magnetic field application member in the wire direction of the magnetic wire.
The second aspect of claim 2, wherein the sub-magnetic field applying member has the same pole as the pole facing the sub-magnetic field applying member of the magnetic field applying member fixed on the upper side, and the generated magnetic field is applied to the magnetic domain wall. Domain wall moving element. The sub-magnetic field applying member is provided on both sides of the magnetic field applying member and is connected to the magnetic thin wire.
The domain wall moving element according to claim 3 or 4, wherein a current is supplied to the magnetic wire via the submagnetic field application member. The domain wall moving element according to any one of claims 1 to 5, wherein the magnetic anisotropy material of the magnetic layer is a magnetic optical material. A magnetic storage element including the domain wall moving element according to any one of claims 1 to 6.
In the magnetic thin wire, the channel layer is laminated under the magnetic layer, and the magnetic wire is laminated.
A magnetic storage element characterized in that a reference layer made of a vertically magnetic anisotropy material is laminated on the upper surface of the magnetic wall within the moving range of the magnetic layer with a non-magnetic metal film or an insulating film interposed therebetween. A spatial light modulator in which the domain wall moving element according to claim 6 is provided in a pixel, and light is incident and reflected from above. A magnetic memory including the magnetic storage element according to claim 7 in a memory cell.

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