JP5202450B2 - Local magnetic field generation device, magnetic field sensor, and magnetic head - Google Patents

Description

  The present invention relates to a local magnetic field generation device using a spin Hall effect, a magnetic sensor, and a magnetic head.

  Electrons have three internal degrees of freedom in addition to the charge that charges electrical conduction, the spin that loads magnetism, and the orbit that means the spatial spread of electrons, and their interaction brings new properties to matter. Has become clear. In recent years, instead of semiconductor devices that utilize the charge of electrons, it has been obtained from the correlation between magnetism and conduction in order to control the internal degrees of freedom of electrons that have not been considered in conventional electronics and to develop new functions. Attention has been focused on the development of spintronic materials and devices that actively utilize the properties of electron spin (Non-Patent Document 1). The information on the electron spin and the spin orbit spatially depends on the ratio of the distance L and the spin diffusion length λ, and decays exponentially according to exp (−L / λ). Therefore, the spatial scale that exhibits the properties of electron spin and spin orbit has the restriction that it is about the same as the spin diffusion length, but with the development of microfabrication technology, in the magnetic nanostructure system of about the spin diffusion length λ, As a tunnel magnetoresistive element using spin injection, a spin injection element has been proposed (Non-Patent Document 2). In addition, when a charge current is passed through a nonmagnetic metal or semiconductor, a spin Hall effect is generated, in which spin-up orbit interaction causes spin-up electrons and spin-down electrons to be bent in opposite directions in the non-magnetic material. As a result, a spin current is generated in the normal direction of the plane formed by the direction of the spin and the current direction, causing spin accumulation at the sample edge (charge current induced spin Hall effect). Furthermore, the reverse process of this effect is the reverse spin Hall effect in which the spin current injected from the ferromagnetic material into the nonmagnetic material induces a charge flow in the normal direction of the plane formed by the spin direction and the spin current direction. Bring (spin current induced spin Hall effect).

Spin Dependent Transport in Magnetic Nanostructures, edited by S. Maekawa and T. Shinjo (Taylor Francis, New York, 2002). F. E. Jedema et al., “Electrical detection of spin precession in a metallic mesoscopic spin valve”, 2002, Nature, Vol.416, p. 713

 In a device using a spin current, a low output signal intensity is difficult in practical use. Further, as the density of media increases, the resolution of magnetic recording heads and magnetic reproducing heads is required to be increased.

  The element described in Non-Patent Document 2 described above relates to a memory and a sensor using a magnetization detection effect by spin accumulation and spin current injection magnetization reversal. Non-Patent Document 1 describes a Hall voltage detection method using spin-polarized electrons injected from a ferromagnetic layer into a semiconductor. However, it discloses a method for generating a magnetic field using a spin-polarized current, and an external magnetic field. There is no disclosure of a configuration or method for detecting the direction in which the ferromagnetic layer is magnetized.

  An object of the present invention is to provide a local magnetic field generating device using spin accumulation by the spin Hall effect. Another object of the present invention is to provide a magnetic recording head having an effect of reversing the magnetization direction of a medium using a local magnetic field generating device using a spin Hall effect. Another object of the present invention is to provide a local magnetic field sensing device using charge accumulation by the spin Hall effect. Another object of the present invention is to provide a magnetic reproducing head that detects the direction of a leakage magnetic field from a densified medium as a signal by using a magnetic field detection device using a spin Hall effect. A further object of the present invention is to provide an integrated magnetic head for magnetic recording and reading using a local magnetic field generation device and a magnetic field detection device using the spin Hall effect.

  In the present invention, by using a spin Hall effect element having a curved current path, polarized spin electrons are accumulated in a minute region inside the curved curve, and a local magnetic field having an effective useful intensity is generated. An element that generates a strong local magnetic field can be obtained by efficiently accumulating spin in a minute region using an annular spin Hall effect element. The present invention uses a spin Hall effect layer made of a nonmagnetic material having a strong spin-orbit interaction that brings about a spin Hall effect, and forms a geometric shape with one electron accumulation point due to the spin Hall effect as one point. This realizes the generation of a magnetic field by efficient spin accumulation in a minute region.

  The local magnetic field generation device of the present invention includes a spin Hall effect element having a spin Hall effect layer made of a nonmagnetic material and having a curved portion, a pair of electrode terminals for passing a current to the spin Hall effect element, and a pair of electrode terminals And a magnetic field is generated by polarized spin electrons accumulated in the curved inner region of the bending portion. The planar shape of the spin Hall effect layer is typically a partial ring with a part cut away, or a shape in which a plurality of partial rings are connected.

  As an example, when the spin Hall effect element has a shape of one partial ring with a part cut away, the local magnetic field generating device can generate a magnetic field in a direction perpendicular to the film surface of the spin Hall effect element. As another example, the local magnetic field generating device generates a magnetic field in a direction parallel to the film surface of the spin Hall effect element when the shape of the spin Hall effect element is a shape in which two partial rings are cut out. be able to. In addition, when a ferromagnetic layer is disposed on the curved portion of the spin Hall effect element via a nonmagnetic insulating layer, the generated magnetic field strength can be increased.

  The magnetic recording head of the present invention uses the above-mentioned local magnetic field generating device as a magnetic field generating unit, and applies a magnetic field generated by polarized spin electrons accumulated in the curved inner region of the curved part of the spin Hall effect element to the magnetic recording medium. Has an opening for

  When the spin Hall effect element has a shape consisting of one partial ring with a part cut away, this magnetic head can be used as a recording head for perpendicular magnetic recording. Further, when the spin Hall effect element has a shape in which two partial rings with a part cut away are connected, this magnetic head can be used as a recording head for in-plane magnetic recording.

  In the present invention, by using a spin Hall effect element having a curved current path having a ferromagnetic core at the center, polarized spin electrons are moved in a curved shape from a curved center ferromagnetic core magnetized by an external magnetic field. A voltage is generated at both ends of the curve by injecting in the radial direction. An element that detects a magnetic field in a minute region can be obtained by using an annular spin Hall effect element. The present invention employs a spin Hall effect layer made of a nonmagnetic material having a strong spin-orbit interaction that brings about a spin Hall effect, and has a geometry in which a spin-polarized electron squeezes into the spin hole layer as one point. By assembling the shape, efficient magnetic field detection from a minute region is realized.

  A local magnetic field detection device according to the present invention includes a non-magnetic spin Hall effect layer, a non-magnetic conductive layer, and a non-magnetic insulator disposed between the non-magnetic spin Hall effect layer and the non-magnetic conductive layer. A spin Hall effect element having a curved portion provided with a laminated film having a layer, a ferromagnetic core positioned in a curved inner minute region of the curved portion, and a pair of electrodes for detecting a voltage induced in the spin Hall effect layer Terminal. A means for applying a current from the nonmagnetic conductive layer to the ferromagnetic core is provided, and a voltage is applied across the spin Hall effect layer by polarized spin electron injection from the magnetized ferromagnetic core to the spin Hall effect layer. generate. The planar shape of the spin Hall effect layer is typically a partial ring with a part cut away, or a shape in which a plurality of partial rings are connected.

  As an example, when the spin Hall effect element has a partial ring shape with a part cut away, the local magnetic field detection device can detect a magnetic field in a direction perpendicular to the film surface of the spin Hall effect element. As another example, the local magnetic field detection device detects a magnetic field in a direction parallel to the film surface of the spin Hall effect element when the shape of the spin Hall effect element is a shape in which two partial rings are cut out. be able to.

  The magnetic read head of the present invention uses the above-mentioned local magnetic field detection device as a magnetic field detection unit, and detects a leakage magnetic field from a magnetic recording medium that magnetizes a ferromagnetic core in the curved inner region of the curved part of the spin Hall effect element. And a magnetic shield having a plurality of openings.

  When the spin Hall effect element has a shape consisting of one partial ring with a part cut away, this magnetic head can be used as a recording head for perpendicular magnetic recording. Further, when the spin Hall effect element has a shape in which two partial rings with a part cut away are connected, this magnetic head can be used as a recording head for in-plane magnetic recording.

  The integrated magnetic head of the present invention uses the local magnetic field detection device as a magnetic field detection unit, the local magnetic field generation device as a magnetic field generation unit, and nonmagnetic insulation between the local magnetic field detection device and the local magnetic field generation device. The body layer has an opening for applying a magnetic field generated in the curved inner region to the magnetic recording medium or detecting a leakage magnetic field from the magnetic recording medium.

  According to the present invention, a strong magnetic field can be locally generated by efficient spin accumulation in a minute region. Further, according to the present invention, the magnetic field from the high-density recording medium can be detected with high resolution.

The figure which shows the structural example of the local magnetic field generation device of this invention using a spin Hall effect element. The figure which shows the basic structural example of the local magnetic field generation device by this invention. The figure which shows the structural example containing the electric current path of the spin Hall effect layer used for the local magnetic field generation device of this invention. The top view and perspective view which show the other example of the local magnetic field generation device which concerns on this invention. The figure which showed the electric current distribution in the nonmagnetic spin Hall effect layer of a spin Hall effect element. The figure which shows the basic structural example of the C-shaped local magnetic field detection device by this invention. The figure which shows the basic structural example of the S-shaped local magnetic field detection device by this invention. The figure which shows the structural example containing the electric current path of the spin Hall effect layer used for the C-shaped local magnetic field detection device by this invention. The figure which shows the structural example containing the electric current path of the spin Hall effect layer used for the S-shaped local magnetic field detection device by this invention. The figure which showed the electrochemical potential distribution in the nonmagnetic spin Hall effect layer of a spin Hall effect element. The figure which shows the structural example of the spin Hall effect element used for the local magnetic field generation device of this invention by an Example. 1 is a diagram showing a configuration example of a magnetic recording head according to the present invention. 1 is a diagram showing a configuration example of a magnetic recording head according to the present invention. 1 is a diagram showing a configuration example of a magnetic recording head according to the present invention. The figure which shows the structural example of the C-shaped local magnetic field detection device of this invention using a spin Hall effect element. The figure which shows the structural example of the spin Hall effect element used for the local magnetic field detection device by this invention. The figure which shows the structural example of the S-shaped local magnetic field detection device of this invention using a spin Hall effect element. 1 is a diagram showing a configuration example of a magnetic reproducing head according to the present invention. 1 is a diagram showing a configuration example of a magnetic reproducing head according to the present invention. 1 is a diagram showing a configuration example of a magnetic reproducing head according to the present invention. The figure which shows the structural example of the spin Hall effect element used for the local magnetic field detection device by this invention. FIG. 3 is a diagram illustrating a configuration example of an integrated magnetic head according to the present invention. The figure which shows the structural example of the spin Hall effect element used for the integrated local magnetic head by this invention. FIG. 3 is a diagram illustrating a configuration example of an integrated magnetic head according to the present invention. FIG. 3 is a diagram illustrating a configuration example of an integrated magnetic head according to the present invention. The figure which shows the structural example of the spin Hall effect element used for the integrated local magnetic head by this invention. 1 is a schematic configuration diagram of a magnetic disk device.

First, the configuration and operation of the local magnetic field generating device in the present invention will be described.
FIG. 2 is a diagram showing a basic configuration example of a local magnetic field generating device according to the present invention. In the local magnetic field generating device 110 shown in FIG. 2A, the nonmagnetic spin Hall effect layer 11 has a single annular shape with a part of the ring cut out. The inner diameter r ₀ of the spin Hall layer, a magnetic field is generated in the inner diameter near H, spin diffusion length λ in the spin Hall effect layer, the carrier concentration N, the coefficient of the spin Hall effect alpha _H, when the Bohr magneton mu _B, r ₀ = λ (1-H / ( H + Nα H μ B)) satisfying the ^1/2. The nonmagnetic spin Hall effect layer 11 is in contact with the nonmagnetic electrode terminals 21 and 22 at the two end surfaces of the cutout portion. The curved portion in the spin Hall effect layer shown in FIG. 2A has a C shape with a part of the ring cut out, but the curved portion does not necessarily have to be a part of the ring. As shown in -1), it may have a shape in which a part of an angular annular body is cut out. Further, the current path is curved as a whole, such as a half shape of an annulus as shown in FIG. 2A-2 and a half shape of a polygonal annulus as shown in FIG. Any shape can be used. The electrode terminals 21 and 22 are provided so as to face each other in the structural example of FIG. 2A-1, and are provided in the same direction in the structural examples of FIGS. 2A-2 and 2A-3.

  The local magnetic field generating device 210 shown in FIG. 2B includes a nonmagnetic spin Hall effect layer 11 having a shape in which a plurality of rings each having a cutout portion are connected, and electrode terminals 21 are provided on free end faces at both ends. , 22. The curved portion of the spin Hall effect layer shown in FIG. 2 (b) has an S shape in which two partial rings are connected in opposite directions, but it is not always necessary to combine the partial rings. As shown in FIG. 2 (b-1), an angular ring may be combined in an S shape. Also, a shape in which two partial rings shown in FIG. 2 (a-2) are joined as shown in FIG. 2 (b-2), or a combination of angular rings as shown in FIG. 2 (b-3). You may comprise a curved part by shape. The end surfaces of the spin Hall effect layer on which the electrode terminals 21 and 22 are provided are opposed to each other with the axis being shifted in FIGS. 2B and 2B-1, and FIG. In the case of (b-2), the axes are offset from each other and face in opposite directions.

  FIG. 3 is a diagram showing an example of the structure including the current path of the spin Hall effect layer of the local magnetic field generating device according to the present invention, and corresponds to a cross-sectional view along AB shown by a dotted line in FIG. 3A to 3C are schematic views showing the basic structure of the laminated film, and FIGS. 3D to 3G are schematic views showing examples of the multilayer film in which the basic structure is laminated in multiple layers.

  FIG. 3A shows an example of a nonmagnetic spin Hall effect layer 11 made of a single layer. FIG. 3B shows a structural example of a laminated film in which the nonmagnetic spin Hall effect layer 11 and the ferromagnetic layer 12 are laminated, and FIG. 3C shows the nonmagnetic spin Hall effect layer 11 and the ferromagnetic material. 3 is a view showing an example of a laminated film in which a nonmagnetic insulator layer 13 is disposed between layers 12. FIG. These multilayer films may be used as shown in FIGS. 3D, 3E, 3F, and 3G. In the case of the multilayer film shown in FIG. 3D, the electrodes 21 bonded to the end faces of the spin Hall effect layers are separated from each other. However, as shown in FIG. The electrode joined to the end surface may be connected.

  The spin current from the ferromagnetic layer 12 to the nonmagnetic spin Hall effect layer 11 is tunneled from the ferromagnetic layer 12 to the spin Hall effect element through the thin nonmagnetic insulator layer 13 serving as a barrier layer. Since the stagnation occurs and the spin current in the nonmagnetic spin Hall effect layer 11 is increased, the magnetic field generation effect due to the spin accumulation due to the spin Hall effect can be increased. In addition, the use of a multilayer film makes it possible to increase the magnetic field generation due to spin accumulation several times.

FIG. 4 is a schematic plan view and a perspective schematic view showing another example of the local magnetic field generating device according to the present invention. The local magnetic field generating device 120 shown in FIG. 4A has a nonmagnetic insulating layer formed on one side of the nonmagnetic spin Hall effect layer 11 constituting the local magnetic field generating device 110 having an inner diameter of 2r ₀ shown in FIG. A pillar-shaped ferromagnetic layer 30 is disposed through the body layer 13. FIG. 4B is a perspective view thereof. In the local magnetic field generating device of this example, the magnetic field generated in the vicinity of the inner diameter of the C-shaped partial ring by the spin Hall effect element magnetizes the ferromagnetic layer 30, so that the magnetic flux density B inside the ferromagnetic layer 30 is = Μ ₀ H + Ms (H is an applied magnetic field and Ms is a saturation magnetization) is a local magnetic field generated from the local magnetic field generating device. Therefore, there is an advantage that the strength of the generated magnetic field can be increased by connecting the ferromagnetic layers 30.

Further, the local magnetic field generating device 220 shown in FIG. 4C is nonmagnetic on one side of the nonmagnetic spin Hall effect layer 11 constituting the local magnetic field generating device 210 having the inner diameter 2r ₀ shown in FIG. Pillar-shaped ferromagnetic layers 31 and 32 are arranged with an insulator layer 13 interposed therebetween. FIG. 4D is a perspective view thereof. The local magnetic field generating device of the present embodiment also has an advantage that the intensity of the generated magnetic field can be increased because the magnetic field generated in the vicinity of the inner diameter by the spin Hall effect element magnetizes the ferromagnetic layers 31 and 32.

  In addition, since the spin current exponentially decays according to exp (−L / λ) with respect to the distance L and the spin diffusion length λ, the spin current is 1/5, 3 of λ at a distance longer than λ. If it is twice or more, it becomes smaller than 1/20. In an actual device, it is difficult to eliminate impurities and twin defects, and it is considered that the spin current is further reduced, and the effective spin current becomes almost zero at 3 times or more of λ. Therefore, in order to accumulate the polarized spin electrons in the minute region inside the curved curved shape and complete the separation from the reverse polarized spin electrons, the width of the spin Hall effect layer is 3 of the spin diffusion length λ. If it is more than double. Further, the thickness at which the spin current spilling effect due to the connection of the ferromagnetic layers 12 is not attenuated to 70% or less even at the center of the spin Hall effect layer is smaller than twice the spin diffusion length λ. In the local magnetic field generating devices 110, 120, 210, and 220 according to the present invention, the width of the nonmagnetic material 11 serving as the spin Hall effect layer is more than three times the spin diffusion length of the material constituting the nonmagnetic spin Hall effect layer. It is preferable that the width is wide. Further, in a spin Hall effect element including a laminated film in which the spin Hall effect layer 11 and the ferromagnetic layer 12 are laminated, the thickness of the nonmagnetic material 11 serving as the spin Hall effect layer constitutes the nonmagnetic material 11. The spin diffusion length λ of the material is preferably not more than twice.

In the local magnetic field generating device of the present invention, the ferromagnetic layer 12 is made of a material made of Co, Ni, Fe, or an alloy or compound containing at least one of these elements as a main component. The nonmagnetic insulator intermediate layer 13 is made of a material containing at least one of Al ₂ O ₃ , AlN, SiO ₂ , HfO ₂ , Zr ₂ O ₃ , Cr ₂ O ₃ , MgO, TiO ₂ , and SrTiO _3. It is composed of a single layer film or a laminated film. Preferably, CoFeB is used for the ferromagnetic layer 11 and MgO is used for the nonmagnetic insulator intermediate layer 13.

  In metals, the spin-orbit interaction Hamiltonian causing the spin Hall effect is expressed by the following equation (1) using the atomic number Z, the orbital angular momentum vector Ι, and the spin s.

ここで、ｍ_eは電子の質量、ｒは電子の原子核中心からの距離、μ₀は真空の透磁率、ｈはプランク定数、ｅは電気素量を表す。

Here, m _e represents the mass of the electron, r represents the distance from the electron nucleus center, μ ₀ represents the magnetic permeability in vacuum, h represents the Planck's constant, and e represents the elementary charge.

  As shown in Equation (1), the spin orbit interaction is proportional to the atomic number. Therefore, in order to realize a remarkable spin accumulation effect due to strong spin-orbit interaction, it is necessary to use a nonmagnetic material having a large atomic number as a material. In addition, while the spin diffusion length of metal is 0.1 to 0.01 μm, in semiconductors, the spin diffusion length λ is as high as about 1 μm, and it is known that the spin polarization is maintained over the macro scale. ing. This has an advantage that the allowable range can be widened with respect to the thickness of the spin Hall effect layer. Furthermore, it has been theoretically shown that there is a universal spin Hall conductivity in the spin Hall effect in an impurity-free semiconductor, and furthermore, a zero gap semiconductor (HgTe, HgSe, etc.), a narrow gap semiconductor (PbTe). , PbSe, PbS, etc.), it has been reported that the spin Hall effect appears even when the electrical conductivity in the longitudinal direction not doped is zero. Therefore, in a clean semiconductor, the spin Hall coefficient is remarkably increased.

The spin Hall current j _s ^H newly induced by the spin Hall effect is expressed by the following equation (2) using the spin quantization axis direction s hat, the current density j _q and the coefficient α _H determined by the material. Is done.

Since the spin Hall current j _s ^H contributes to the spin accumulation, if the material is determined, the spin accumulation effect increases as the current density j _q increases.

  When a constant voltage is applied between the electrodes of the spin Hall effect element of the present invention, a current flows in a ring shape in the plane of the nonmagnetic spin Hall effect layer 11. FIG. 5A is a diagram illustrating the shape of the spin Hall effect element, and FIG. 5B is a schematic diagram of the cross section and a current density distribution in the radial direction of the annular current.

5A, that is, an annular notch structure having an inner diameter of 100 nm (r ₀ = 50 nm) obtained by cutting off corners of a semiconductor GaAs layer 11 having a thickness of 100 nm, a width of 300 nm, and a height of 300 nm, has aluminum at both ends. In the spin Hall effect element in which the electrodes 21 and 22 were joined, a voltage of 0.1 V was applied between the electrodes. Current flows as indicated by the annular arrow. Since the current path becomes shorter toward the center side, the current density is higher. In the case of a circular current, since there is a relationship of the equation (3) among the resistivity ρ, the radius r of the circular current, and the applied voltage V between the electrodes, as shown in FIG. In the cross section, the distance dependence of the current density from the ring center is inversely proportional to the distance. Here, 40 indicates the direction of the current flowing through the cross section. Accordingly, in the annular structure, the induced spin Hall current is stronger toward the center. Thereby, a high spin accumulation effect can be expected.

  In the local magnetic field generating device of the present invention, the nonmagnetic material 11 serving as the spin Hall effect layer may be a nonmagnetic material having a large spin Hall effect such as Au or Pt having an atomic number larger than Cu used for wiring, or the following: Compound semiconductors having a large spin Hall effect, that is, gallium arsenide (GaAs), indium arsenide (InAs), aluminum arsenic (AlAs), indium gallium arsenide (InGaAs), indium gallium nitrogen-gallium nitrogen superlattice (InGaN / GaN), tellurium Mercury halide (HgTe), mercury selenide (HgSe), β-hydrogen sulfide (β-HgS), α-tin (α-Sn), lead telluride (PbTe), lead selenide (PbSe), lead sulfide (PbS) ) Or a GaAs-based semiconductor. In addition, the thickness of the nonmagnetic spin Hall effect layer 11 is thinner than twice the metal spin diffusion length of 0.1 to 0.01 μm (0.2 to 0.02 μm) when a metal is used. When a semiconductor is used, it is formed to be thinner than twice the semiconductor spin diffusion length of about 1 μm (about 2 μm).

Next, the configuration and operation of the local magnetic field detection device according to the present invention will be described.
FIG. 6 is a diagram showing a basic configuration example of a C-shaped local magnetic field detection device according to the present invention. In the local magnetic field detection device 310 shown in FIG. 6A, the nonmagnetic spin Hall effect layer 11 that is in contact with the nonmagnetic conductive layer 14 via the nonmagnetic insulator layer 13 is a single piece in which a part of the ring is notched. It has a C-shaped annular shape. A ferromagnetic core 30 protruding downward is provided at the center of the C-shaped annular shape. The nonmagnetic spin Hall effect layer 11 is in contact with the nonmagnetic electrode terminals 21 and 22 at the two end surfaces of the cutout portion. The electrode terminals 21 and 22 and the ferromagnetic core 30 are insulated. In addition, stagnation of spin current from the ferromagnetic core 30 to the nonmagnetic spin Hall effect layer 11 occurs, but when a current is passed from the nonmagnetic conductive layer 14 to the ferromagnetic core 30, the nonmagnetic spin Hall effect is generated. Since the injection of the spin-polarized current into the layer 11 is increased, the magnetic field detection effect by the spin Hall effect can be increased.

  Although the curved portion in the spin Hall effect layer shown in FIG. 6A has a C shape with a part of the ring cut out, the curved portion does not necessarily have to be a part of the ring. As shown in (), a shape obtained by cutting out a part of an angular annular body may be used. Moreover, the shape which curves the current path as a whole, such as a half shape of an annular shape as shown in FIG. 6C and a half shape of a polygonal annular body as shown in FIG. If it is. The electrode terminals 21 and 22 are provided to face each other in the structural examples of FIGS. 6A and 6B, and are provided to face in the same direction in the structural examples of FIGS. 6C and 6D.

  FIG. 7 is a diagram showing a basic configuration example of an S-shaped local magnetic field detection device according to the present invention. The local magnetic field detection device 410 shown in FIG. 7A is in contact with two non-magnetic conductive layers 14 and 15 having a C-shaped ring shape having a notch in part via the non-magnetic insulator layer 13. An S-shaped non-magnetic spin Hall effect layer 11 in which two C-shaped rings are connected is provided, and electrode terminals 21 and 22 are provided on free end faces at both ends. Ferromagnetic cores 31 and 32 projecting downward are provided at the central portions of the two C-shaped rings. The electrode terminals 21 and 22 and the ferromagnetic cores 31 and 32 are insulated. In addition, stagnation of spin current from the ferromagnetic cores 31 and 32 to the nonmagnetic spin Hall effect layer 11 occurs, but when a current is passed from the nonmagnetic conductive layers 14 and 15 to the ferromagnetic cores 31 and 32, Since injection of the spin-polarized current into the nonmagnetic spin Hall effect layer 11 is increased, the magnetic field detection effect by the spin Hall effect can be increased. At this time, since it is necessary to reverse the direction of the current flowing from the nonmagnetic conductive layer 14 to the ferromagnetic core 31 and the direction of the current flowing from the nonmagnetic conductive layer 15 to the ferromagnetic core 32, the two nonmagnetic The conductive layers 14 and 15 are formed with an insulating layer provided at a position C interposed therebetween and are electrically insulated from each other.

  Although the curved portion of the spin Hall effect layer 11 shown in FIG. 7A has an S shape in which two partial rings are connected in the opposite direction, it does not necessarily have to be a combination of partial rings. As shown in FIG. 7B, an angular ring may be combined in an S shape. Further, as shown in FIG. 7C, the curved portion has a shape in which two partial rings shown in FIG. 6C are joined, or a combined shape of angular rings as shown in FIG. 7D. May be configured. The end faces of the spin Hall effect layer on which the electrode terminals 21 and 22 are provided are opposed to each other with an axis offset in FIGS. 7A and 7B, and are shown in FIGS. 7C and 7D. In some cases, the axes are shifted from each other in opposite directions.

  FIG. 8 is a view showing a structural example including the current path of the spin Hall effect layer of the C-shaped local magnetic field detection device according to the present invention, and corresponds to a cross-sectional view taken along AB shown by a dotted line in FIG. FIG. 8A shows an example of the nonmagnetic spin Hall effect layer 11 made of a single layer of the device 310. 8B, 8C, and 8D show structural examples of a multilayer film in which the spin Hall effect layer 11 and the nonmagnetic insulator layer 13 of the device 310 are stacked. FIG. 8B is a diagram in the case where the electrode terminals 21 and 22 bonded to the end face of each spin Hall effect layer 11 are separated via the nonmagnetic insulator layer 13. As shown in FIG. 8C, the electrodes 21 and 22 joined to the end faces of the plurality of spin Hall effect layers 11 may be connected. FIG. 8D is a diagram showing an example in which the nonmagnetic high resistance layer 16 is disposed between the nonmagnetic spin Hall effect layer 11 and the nonmagnetic electrode terminals 21 and 22 of the device 310. By providing a structure in which contact is made through a tunnel junction using the nonmagnetic high-resistance layer 16, the final output can be increased. In addition, the magnetic field detection signal can be increased by the number of layers by using the multilayer film.

  FIG. 9 is a view showing a structural example including the current path of the spin Hall effect layer of the S-shaped local magnetic field detection device according to the present invention, and corresponds to a cross-sectional view along the ACB indicated by a dotted line in FIG. FIG. 9A shows an example of the nonmagnetic spin Hall effect layer 11 made of a single layer of the device 410. 9B, 9C, and 9D show structural examples of a multilayer film in which the spin Hall effect layer 11 and the nonmagnetic insulator layer 13 of the device 410 are stacked. FIG. 9B is a diagram in the case where the electrode terminals 21 and 22 bonded to the end face of each spin Hall effect layer 11 are separated via an insulating layer. As shown in FIG. 9C, electrodes joined to the end faces of the plurality of spin Hall effect layers 11 may be connected. FIG. 9D is a diagram showing an example in which the nonmagnetic high resistance layer 16 is disposed between the nonmagnetic spin Hall effect layer 11 and the nonmagnetic electrode terminals 21 and 22 of the device 410. By using a multilayer film, it is possible to increase the magnetic field detection signal by the number of layers. In any case, the spin Hall effect layer 11 is continuously formed between the electrode terminals 21 and 22. However, as shown in the figure, the two nonmagnetic conductive layers 14 and 15 are formed discontinuously at point C and are electrically insulated from each other. The reason is that, as described above, it is necessary to reverse the direction of the current flowing from the nonmagnetic conductive layer 14 to the ferromagnetic core 31 and the direction of the current flowing from the nonmagnetic conductive layer 15 to the ferromagnetic core 32. Because.

The spin Hall current j _q ^H induced by the inverse spin Hall effect of the spin-polarized current is expressed by the following equation using the spin quantization direction s hat, the spin-polarized current density j _s and the coefficient α _H determined by the material. It is represented by (4).

Since the spin Hall current j _s ^H contributes to the spin accumulation, if the material is determined, the spin accumulation effect increases as the current density j _q increases.

When a current is passed from the non-magnetic conductive layer of the present invention in the direction of the ferromagnetic core, the current I _↑ due to the upward spin and the current I _↓ due to the downward spin flow toward the core center in the ferromagnetic core. At this time, in the ferromagnetic core, there is a bias between I _↑ and I _↓ as in the equation (5-1), while there is no bias in the spin Hall effect layer as in the equation (5-2). Does not flow, so I _↑ = -I _↓ . As a result, in the spin Hall effect layer near the junction with the ferromagnetic core, the electrochemical potential (ECP) μ _↑ and μ _↓ of the upward spin and downward spin is spin-polarized by Δμ = μ _↑ −μ _↓ Non-equilibrium magnetization is induced in the nearby spin Hall effect layer. Thereby, a spin-polarized current in the radial direction is injected into the nonmagnetic spin Hall effect layer.

  When the ferromagnetic core is magnetized upward in the direction perpendicular to the device surface as shown in FIG. 15C described later, the spin-polarized current polarized in the upward direction perpendicular to the device surface becomes a non-magnetic spin Hall effect layer. Injected in the radial direction. The spin-polarized current injected at this time is accumulated in the electrode 22 as both electrons having upward and downward spins are bent in the same direction due to the spin Hall effect in the nonmagnetic spin Hall effect layer. As a result, the electrode 22 is negatively charged and a potential difference is generated between the electrodes. When the ferromagnetic core is magnetized in the opposite direction, electrons accumulate in the electrode 21 and the polarity of the potential difference is reversed.

FIG. 10A is a schematic cross-sectional view taken along AB of the spin Hall effect element 311 shown in FIG. FIG. 10B is a diagram showing a simulation result showing the x-direction distribution of ECPs μ _↑ and μ _↓ of the upward spin and the downward spin in the spin Hall effect layer 11 made of Pt of the spin Hall effect element 311.

As shown in FIG. 10A, the spin Hall effect element is made of a Cu (20 nm) / Al ₂ O ₃ (5 nm) / Pt (10 nm) laminated film, and a permalloy layer (ferromagnetic core) 30 having an inner diameter of 30 nm. It has a structure in which aluminum electrodes 21 and 22 are joined to both ends of a notch end of a spin-hole effect Pt layer 11 having a ring-like notch structure with a ring. As shown in FIG. 10A, when the x coordinate is set in the radial direction from the center of the permalloy layer 30, a current 41 of 100 μA is applied from the Cu conductive layer 14 to the ferromagnetic permalloy layer 30. At this time, as shown in FIG. 10B, in the spin Hall effect Pt layer 11, an x-direction distribution is seen in the difference (ΔECP) between the electrochemical potentials of the upward spin and the downward spin. The slope of ΔECP is proportional to the magnitude of the spin current flowing into the Pt layer 11. It shows that an average spin current of 1.12 × 10 ⁵ A / cm ² is injected from the ferromagnetic permalloy layer 30 to the Pt layer 11. It can be seen that spin injection from the permalloy layer 30 to the spin nonmagnetic spin Hall effect Pt layer 11 occurs.

In the local magnetic field detection device of the present invention, the nonmagnetic material 11 serving as the spin Hall effect layer may be a nonmagnetic material having a large spin Hall effect such as Au or Pt having an atomic number larger than Cu used for wiring, or the following: Compound semiconductors having a large spin Hall effect, that is, gallium arsenide (GaAs), indium arsenide (InAs), aluminum arsenic (AlAs), indium gallium arsenide (InGaAs), indium gallium nitrogen-gallium nitrogen superlattice (InGaN / GaN), tellurium Mercury halide (HgTe), mercury selenide (HgSe), β-hydrogen sulfide (β-HgS), α-tin (α-Sn), lead telluride (PbTe), lead selenide (PbSe), lead sulfide (PbS) ) Or a GaAs-based semiconductor. In addition, the thickness of the nonmagnetic spin Hall effect layer 11 is thinner than twice the metal spin diffusion length of 0.1 to 0.01 μm (0.2 to 0.02 μm) when a metal is used. When a semiconductor is used, it is formed to be thinner than twice the semiconductor spin diffusion length of about 1 μm (about 2 μm).
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[Example 1]
FIG. 1 is a diagram showing a configuration example of a local magnetic field generation device of the present invention using the spin Hall effect. 1 (a) and 1 (c) are schematic plan views showing examples of the configuration of the local magnetic field generating device, and FIGS. 1 (b) and 1 (d) show the behavior of spin current by connection to an external circuit. It is a schematic diagram.

  In the local magnetic field generation device 1000 shown in FIG. 1A, each spin Hall effect layer having a thickness d = 100 nm, a ring width w = 4 μm, and a ring inner diameter of 40 nm is laminated through a 10 nm MgO film. A spin Hall effect element 113 having a structure was used. As the nonmagnetic material 11 to be the spin Hall effect layer, GaAS having a spin diffusion length of 1 μm was used. FIG. 11A is a schematic perspective view of the spin Hall effect element 113.

A laminated multilayer film of 10 layers of (GaAs (100 nm) / MgO (10 nm)) ₁₀ was formed on a MgO (001) single crystal substrate using a sputtering apparatus. The laminated multilayer film is formed into a C-shaped annular shape having an outer diameter of 8040 nm and an inner diameter of 40 nm by an electron beam lithography technique, and Cu electrodes 21 and 22 having a width of 4000 nm, a length of 100 nm, and a thickness of 200 nm are connected to the side surfaces of the laminated multilayer film. To do. At this time, d <2λ, 5μ> 3λ is satisfied. The local magnetic field generating device 1000 has a function of accumulating spins inside the ring in the charge flow applied to the nonmagnetic spin Hall effect layer 11.

  As shown in FIG. 1A, a power source 70 for applying a current in the film surface direction is connected to the laminated film of the spin Hall effect element 113, and a constant voltage is applied between the electrode terminals 21 and 22 made of a nonmagnetic material. As a result, a current flows to the nonmagnetic spin Hall effect layer 11. FIG. 1B shows the behavior of the current and spin current that flow due to the connection with the external circuit shown in FIG. Dotted arrows represent the directions of upward spin electrons 52 and downward spin electrons 53 indicated by white circles, respectively, and the thick double circle 50 represents the direction of magnetization inside the annular nonmagnetic spin Hall effect layer 11. . When a current flows in a ring shape in the film surface direction, electrons in the nonmagnetic spin Hall effect layer 11 are bent by a spin Hall effect in a normal direction of a plane constituted by the direction of the quantization axis and the inflow direction. At this time, the electrons 52 whose spin quantization axis is perpendicular to the film surface of the nonmagnetic spin Hall effect layer are bent toward the ring center in the radial direction of the ring, while the spin quantization axis is the film surface. The electrons 53 that are vertically downward are bent in the outer edge direction. As a result, the upward vertical spin electrons 52 are accumulated at the inner edge of the spin Hall effect element 113, and a magnetic field perpendicular to the film surface is generated near the inner edge.

  When the voltage applied between the electrode terminals 21 and 22 is reversed, the spin electrons are bent in the reverse direction in the nonmagnetic spin Hall effect layer 11. As a result, the polarity of the magnetic field generated near the inner edge of the spin Hall effect element 113 is also reversed. Thereby, a local magnetic field can be generated at the inner edge of the spin Hall effect element 113.

  Further, when a spin Hall effect element 215 of a type in which two partial rings are connected as in the local magnetic field generating device 2000 shown in FIG. 1C is used, a curved nonmagnetic spin is obtained as shown in FIG. Spin electrons 52 and 53 having different polarities are separately accumulated in the two curve inner regions of the Hall effect layer 11. Thereby, a local magnetic field parallel to the film surface can be generated.

The magnetic field H generated in the vicinity of the inner diameter includes the inner diameter r ₀ of the spin Hall effect element 113, the coefficient α _H of the spin Hall effect, the spin diffusion length λ of the semiconductor, the carrier concentration N, the Bohr magneton μ _B , and the vacuum permeability. It is expressed by the following formula (6) using μ ₀ .

As an example, if r ₀ is 20 nm, α _H is 0.01, λ is 1 μm, and N is 10 ¹⁹ cm ⁻³ , μ ₀ H to 1.82 Tesla.

[Example 2]
FIG. 12A is a schematic cross-sectional view showing a configuration example of a magnetic recording head 3000 for performing magnetic recording by applying a recording magnetic field to a perpendicular magnetic recording medium together with the magnetic recording medium. FIG. 12B is a schematic perspective view thereof. In this embodiment, the C-shaped local magnetic field generating device 123 shown in FIG. 11C is applied to a recording head for perpendicular magnetic recording.

In the magnetic recording head 3000, a nonmagnetic insulating SiO ₂ layer 13 having an inner diameter of 4 nm, an outer diameter of 4000 nm, and a thickness of 10 nm is formed on a base 63 made of a substrate and a base material, and an inner diameter of 4 nm and an outer diameter of 4000 nm. , A multilayer film in which nonmagnetic semiconductor GaAs layers 11 having a thickness of 100 nm are alternately stacked is formed. On the multilayer film, a pillar made of a ferromagnetic permalloy layer 30 having a diameter of 12 nm and a thickness of 20 nm is concentric with the ring center via a nonmagnetic insulator SiO ₂ layer 13 having a diameter of 1000 nm and a thickness of 8 nm. Formed in position. Copper electrode terminals 21 and 22 having a width of 1498 nm, a length of 50 nm, and a thickness of 100 nm are formed on the notch end face of the GaAS layer 11.

As shown in the cross-sectional view of FIG. 12A and the perspective schematic view of FIG. 12B, the ferromagnetic permalloy layer 30 faces the top surface of the laminated film at a position close to the surface of the perpendicular magnetic recording medium 60. Be placed. Here, the cross-sectional view of FIG. 12A is a cross-sectional view along AB shown by a dotted line in the schematic perspective view of FIG. The magnetic shield 61 is provided between the permalloy layer 30 and the medium 60 so as to surround the medium 60 and the permalloy layer 30 in a ring shape around the local magnetic field generating device 123 formed on the side surface of the GaAs / SiO ₂ multilayer film. It consists of a flat plate to shield. In the shielding flat plate, an opening having a size equal to or smaller than the medium magnetic domain size is provided on the ring center line of the local magnetic field generating device 123. From the opening of the magnetic shield 61, the local magnetic field generated by the local magnetic field generation device 123 and amplified by the permalloy layer 30 is applied to only the rewritten magnetic domain of the medium 60.

In FIG. 12B, the base 63 and the magnetic shield 61 are omitted for easy understanding of the drawing. A symbol 40 in FIG. 12A indicates the direction of current flowing in the local magnetic field generating device 123. The arrows 55 in FIGS. 12A and 12B indicate the magnetization directions of the magnetic domains of the perpendicular magnetic recording medium 60. Also, the white arrow 50 in FIGS. 12A and 12B indicates the direction of the local magnetic field generated using the local magnetic field generating device 123. The magnetic field H generated in the vicinity of the inner diameter of the local magnetic field generating device 123 magnetizes the permalloy layer 30 having a saturation magnetization Ms of 1.08 Tesla. Therefore, the magnetic flux density B = μ ₀ H + Ms in the permalloy layer 30 is the magnetic recording head. A local magnetic field 50 generated from 3000 is obtained. Thus, by connecting the ferromagnetic layer 30, the intensity of the generated magnetic field increases. In addition, the soft magnetic layer 62 under the medium 60 prevents the magnetic field lines from spreading. The direction of magnetization of the magnetic domain of the perpendicular magnetic recording medium 60 is reversed by the local magnetic field 50 generated from the magnetic head 3000.

[Example 3]
FIG. 13A is a schematic cross-sectional view showing a configuration example of a magnetic recording head 3001 for performing magnetic recording by applying a recording magnetic field to an in-plane magnetic recording medium together with the magnetic recording medium. FIG. 13B is a schematic perspective view thereof. In this embodiment, the local magnetic field generating device having a shape in which two partial rings shown in FIG. 11B are connected is applied to a recording head for in-plane magnetic recording. Here, the cross-sectional view of FIG. 13A is a cross-sectional view along the ACB indicated by a dotted line in the schematic perspective view of the local magnetic field generating device shown in FIG.

An S-shaped nonmagnetic Au layer 11 having an inner diameter of 2.5 nm, an outer diameter of 20 nm, and a thickness of 5 nm is formed on a substrate 63 made of a substrate and a base material, and an annular inner diameter of 2.5 nm is similarly formed thereon. The S-shaped ferromagnetic FePt layer 12 having an inner diameter of 2.5 nm, an outer diameter of 20 nm, and a thickness of 5 nm is nonmagnetic with a S-shaped nonmagnetic insulator Al ₂ O ₃ layer 13 having an outer diameter of 20 nm and a thickness of 2 nm. A multilayer film in which the Au layers 11 are alternately stacked is formed. Cu electrode terminals 21 and 22 having a width of 8,75 nm, a length of 10 nm, and a thickness of 5 nm are formed on the side surfaces of the cutout end corresponding to the S-shaped ends of the Au layer 11. The magnetic shield 61 is formed on the side surface of the FePt / Al ₂ O ₃ / Au laminated film and surrounds the local magnetic field generating device in an annular shape, and is provided between the local magnetic field generating device and the medium 60. It is comprised with the flat plate which shields a local magnetic field generation device. In the shielding flat plate portion of the magnetic shield 61, an opening having a size equal to or smaller than the medium magnetic domain size is provided on a straight line extending from the position C of the local magnetic field generating device to the medium 60 vertically. The local magnetic field generated by the local magnetic field generating device is applied to only the rewrite magnetic domain of the medium 60 through the opening of the magnetic shield 61.

  As shown in FIGS. 13A and 13B, the laminated film upper surface of the local magnetic field generating device is disposed so as to face the medium 60 at a position close to the surface of the in-plane magnetic recording medium 60. In FIG. 13B, the base 63 and the magnetic shield 61 are omitted for easy viewing. Symbol 40 in FIG. 13A indicates the direction of current flowing in the local magnetic field generating device. Arrows 55 in FIGS. 13A and 13B indicate the magnetization directions of the magnetic domains of the in-plane magnetic recording medium 60. Moreover, the white arrow 50 in Fig.13 (a) and (b) shows the direction of the local magnetic field generated using the local magnetic field generation device.

Spin electrons having different polarities are separately accumulated inside two curves of the S-shaped nonmagnetic spin Hall effect layer constituting the local magnetic field generating device. Assuming that the conduction electron density of the nonmagnetic Au layer 11 is 10 ²³ cm ⁻³ and α _H is 0.01, the local magnetic field 50 is H and μ ₀ H to 0.74 Tesla. The direction of magnetization of the magnetic domain of the medium 60 can be reversed. Further, instead of the local magnetic field generation device shown in FIG. 11B, a local magnetic field generation device 224 in which the pillars 31 and 32 of the ferromagnetic layer shown in FIG. It may be used. At this time, the magnetic field H generated in the vicinity of the inner diameter at two locations of the local magnetic field generating device 224 magnetizes the ferromagnetic layers 31 and 32 having the saturation magnetization Ms in the opposite directions, so that the polarities inside the ferromagnetic layers 31 and 32 are different. Magnetic flux density B = ± (μ ₀ H + Ms) generates a local magnetic field 50 parallel to the medium surface. By connecting the ferromagnetic layer to the spin Hall effect element, the intensity of the generated magnetic field is increased.

[Example 4]
FIG. 14A is a schematic cross-sectional view showing a configuration example of another magnetic recording head 3002 for performing magnetic recording by applying a recording magnetic field to a perpendicular magnetic recording medium together with the magnetic recording medium. FIG. 14B is a schematic perspective view thereof. In this embodiment, the C-shaped local magnetic field generating device 123 shown in FIG. 11C is applied to a magnetic head for perpendicular magnetic recording.

A Pt layer 11 having an inner diameter of 4 nm, an outer diameter of 30 nm, and a thickness of 4 nm is formed on a substrate 63 made of a substrate and a base material, and a nonmagnetic insulator Al ₂ having an inner diameter of 4 nm, an outer diameter of 30 nm, and a thickness of 10 nm. A ten-layer multilayer film in which the O ₃ layers 13 and the nonmagnetic Pt layers 11 are alternately stacked is formed. Further, on the multilayer film, a pillar made of a ferromagnetic permalloy layer 30 having a diameter of 12 nm and a thickness of 30 nm is concentric with the center of the ring via a nonmagnetic insulator Al ₂ O ₃ layer 13 having a diameter of 30 nm and a thickness of 4 nm. It is formed by arrangement. Cu electrodes 21 and 22 having a width of 13 nm, a length of 10 nm, and a thickness of 140 nm are formed at the side edges of the notch corresponding to both ends of the C-shape of the nonmagnetic Pt layer 11.

Further, as shown in FIGS. 14A and 14B, the local magnetic field generating device 123 is arranged so that the side surface of the Pt / Al ₂ O ₃ laminated film is parallel to the surface of the perpendicular magnetic recording medium 60. The The cross-sectional view of FIG. 14A is a cross-sectional view along AB indicated by a dotted line in the schematic perspective view of the local magnetic field generating device of FIG. The magnetic shield 61 is composed of a portion surrounding the periphery of the local magnetic field generating device 123 formed on the side surface of the Pt / Al ₂ O ₃ laminated film in a ring shape and a flat plate covering the portion. At a position close to the surface of the perpendicular magnetic medium 60 between the ferromagnetic permalloy layer 30 on the magnetic shield formed on the side surface of the Pt / Al ₂ O ₃ laminated film and the shielding flat plate, an opening smaller than the medium magnetic domain size is provided. Yes. The local magnetic field generated by the local magnetic field generating device 123 and amplified by the permalloy layer 30 is applied to only the rewrite magnetic domain of the perpendicular magnetic recording medium 60 through the opening provided in the magnetic shield 61.

In FIG. 14B, the base 63 and the magnetic shield 61 are omitted for easy understanding of the drawing. A symbol 40 in FIG. 14A indicates the direction of current flowing in the local magnetic field generating device 123. The arrows 55 in FIGS. 14A and 14B indicate the magnetization directions of the magnetic domains of the perpendicular magnetic recording medium 60. 14A and 14B indicate the direction of the local magnetic field generated using the local magnetic field generating device 123. Since the magnetic field H generated in the vicinity of the inner diameter of the ring of the local magnetic field generating device 123 magnetizes the permalloy layer 30 having a saturation magnetization Ms of 1.08 Tesla, the magnetic flux density B = ± (μ ₀ H + Ms) inside the permalloy layer is A local magnetic field 50 perpendicular to the medium 60 is generated toward the underlying soft magnetic layer 62. By connecting the ferromagnetic layer 30 to the spin Hall effect element, the intensity of the generated magnetic field is increased. Also, the soft magnetic layer 62 under the medium 60 suppresses the spread of the lines of magnetic force, and the local magnetic field 50 reverses the magnetization of the medium 60.

[Example 5]
FIG. 15 is a diagram illustrating a configuration example of the C-shaped local magnetic field detection device of the present invention using the spin Hall effect. 15A and 15B are schematic plan views showing a configuration example of the local magnetic field detection device, and FIG. 15D is a cross-sectional view taken along a path AB shown in FIG. FIG. 15C is a schematic diagram showing the behavior of the spin current due to connection with an external circuit.

A local magnetic field detection device 1100 shown in FIGS. 15A, 15B, and 15D has an Al ₂ thickness of d = 100 nm, a ring width w = 4 μm, and each spin Hall effect layer having an inner diameter of 30 nm is 10 nm. A spin Hall effect element 311 having a structure in which ten layers are laminated via an O ₃ nonmagnetic insulator film was used. As the nonmagnetic material 11 to be the spin Hall effect layer, GaAS having a spin diffusion length of 1 μm was used. FIG. 16A is a schematic perspective view of the spin Hall effect element 311.

Using a sputtering apparatus, a nonmagnetic conductive layer made of a 20 nm thick Cu film and a nonmagnetic insulator layer made of a 5 nm thick MgO film on a MgO (001) single crystal substrate and (GaAs (100 nm) / MgO (5 nm)) was deposited laminated multilayer film ₁₀ spin Hall layer consisting of 10 layers of molding the hole having an inner diameter of 30nm by patterning by resist milling method using the thickness of 20nm on the laminated multilayer film. Further, Fe is formed using a sputtering apparatus and patterned through a lift-off peeling process to form an Fe pillar having a height of 20 nm and a diameter of 30 nm on the multilayer multilayer film. This Cu (20 nm) / MgO (5 nm) / (GaAs (100 nm) / MgO (5 nm)) ₁₀ / MgO (5 nm) film with an Fe core with a diameter of 30 nm has a notch structure using an electron beam lithography technique. Patterned and formed into a C-shaped annular shape, Cu electrode terminals 21 and 22 having a width of 15 nm, a length of 10 nm, and a thickness of 1050 nm are connected to the side surfaces of the cutout ends corresponding to both ends of the C-shape via the high resistance film 16. . In this local magnetic field detection device 1100, a spin-polarized current that is polarized depending on an external magnetic field is injected from the ferromagnetic core 30 into the nonmagnetic spin Hall effect layer 11, whereby the voltage between both sides of the notch is obtained. Has the function of inducing By providing a structure in which contact is made through a tunnel junction using the high-resistance film 16, it is possible to increase the final output of the voltage induced between the side surfaces of both ends of the notch. Here, in the ferromagnetic core 30, the outer diameter of the pillar region protruding from the spin Hall effect layer may not be the same as the inner diameter of the spin Hall effect layer 11. As shown in FIGS. 16B and 16C, the outer diameter of the pillar region may be larger or smaller than the inner diameter of the spin Hall effect layer 11 in accordance with the local external magnetic field region to be detected. .

  As shown in FIG. 15A, a voltmeter 71 is connected between the side surfaces of both ends of the spin Hall effect layer 11, and as shown in FIG. 15B, the non-magnetic conductive layer 14 and the ferromagnetic core 30 are connected. A power supply 70 for applying a current in the radial direction is connected to flow current from the nonmagnetic conductive layer 14 to the ferromagnetic core 30. In FIG. 15B, the outline of the dotted line indicates the spin Hall effect layer connected via the insulator layer 13. FIG. 15D is a cross-sectional view taken along the path AB in FIG. 15A. The nonmagnetic conductive layer 14 and the spin Hall effect layer 11 form a laminated film with the nonmagnetic insulator layer 13 interposed therebetween, and the ferromagnetic layer is formed. The contact with the body core 30 is shown. FIG. 15 (c) shows the behavior of the current and spin current that flow due to the connection with the external circuit shown in FIGS. 15 (a), (b), and (d). The solid and dotted arrows indicate the direction in which upward spin electrons 52 and downward spin electrons 53 flow as indicated by white circles, respectively, and the thick double circle 50 indicates the direction of magnetization of the ferromagnetic core 30.

  When a current flows in the radial direction from the nonmagnetic conductive layer 14 to the ferromagnetic core 30, the spin polarized current is injected from the ferromagnetic core 30 in the radial direction of the nonmagnetic spin Hall effect layer 11. Occur. The electrons are bent in the normal direction of the plane constituted by the direction of the quantization axis and the inflow direction by the spin Hall effect. At this time, electrons 52 whose spin quantization axis is perpendicular to the film surface of the non-magnetic spin Hall effect layer 11 are injected into the spin Hall effect layer 11, and electrons 53 whose spin quantization axis is perpendicular to the film surface are perpendicular to the film surface. A reverse flow along the radial direction is drawn into the ferromagnetic core 30. As a result, since the upward electrons 52 and the downward electrons 53 are both bent in the same direction, a current indicated by a broken line 40 is generated, and both the upward electrons 52 and the downward electrons 53 are formed on one side surface of one notch of the spin Hall effect element 311. The voltage is accumulated and a voltage is generated between the electrode terminals 21 and 22.

  When the direction of the external magnetic field is reversed, the polarity of the spin-polarized current injected into the nonmagnetic spin Hall effect layer 11 is reversed, and the spin electrons are bent in the opposite direction. As a result, the polarity of the voltage generated between both side surfaces of the cutout of the spin Hall effect element 311 is also reversed. Thereby, the spin Hall effect element 311 can detect a local magnetic field.

[Example 6]
FIG. 17 is a diagram showing a configuration example of the S-shaped local magnetic field detection device of the present invention using the spin Hall effect. 17A and 17B are schematic plan views showing a configuration example of the local magnetic field detection device. FIG. 17D is a cross-sectional view taken along the path AB in FIG. FIG. 17C is a schematic diagram showing the behavior of the spin current due to connection with an external circuit.

  When a spin Hall effect element 411 of a type in which two partial rings are connected as in the local magnetic field detection device 2100 of this embodiment is used, a curved nonmagnetic spin Hall effect layer 11 is formed as shown in FIG. Spin electrons 52 and 53 having different polarities are injected from the two curve inner regions. The solid and dotted arrows represent the flow directions of the upward spin electrons 52 and the downward spin electrons 53 indicated by white circles, respectively, and the thick double circle 50 and the circular cross 51 indicate the magnetization directions of the ferromagnetic cores 30 and 31, respectively. Represent. When a current flows in a radial direction from the nonmagnetic conductive layer 14 to the ferromagnetic cores 30 and 31, spin polarization in the radial direction of the nonmagnetic spin Hall effect layer 11 from the ferromagnetic cores 30 and 31 is performed. Current injection occurs. The electrons are bent in the normal direction of the plane constituted by the direction of the quantization axis and the inflow direction by the spin Hall effect. At this time, as shown in FIG. 17B, the conductive layers 14 and 15 connected to the spin Hall effect layer through the insulating layer are electrically separated from each other, and the ferromagnetic cores 30 and 31 are respectively separated. Connected independently. The power source that applies a current in the radial direction from the nonmagnetic conductive layer 14 to the ferromagnetic core 30 and the power source that applies a current in the radial direction from the nonmagnetic conductive layer 15 to the ferromagnetic core 31 are: Connected with reverse polarity. For example, as shown in FIG. 17 (b), when the potential of the nonmagnetic conductive layer 14 connected to the potential of one ferromagnetic core 30 is set higher, the other ferromagnetic core The potential of the nonmagnetic conductive layer 15 connected to the potential of 31 is set lower. In FIG. 17B, the outline indicated by the dotted line indicates the spin Hall effect layer connected to the nonmagnetic conductive layers 14 and 15 via the insulator layer 13. Since the S-shaped local magnetic field detection device of this embodiment has a structure in which C-shaped elements are connected in series, the signal intensity is almost twice that of the C-shaped elements.

[Example 7]
FIG. 18 is a schematic cross-sectional view showing a configuration example of a magnetic reproducing head 3003 for detecting a leakage magnetic field from a perpendicular magnetic recording medium together with the magnetic recording medium. In this embodiment, the C-shaped local magnetic field detection device 311 shown in FIG. 16A is applied to a reproducing head for a perpendicular magnetic recording medium.

In the magnetic reproducing head 3003, a nonmagnetic insulator SiO ₂ layer 13 is formed on a substrate 63 made of a substrate and a base material, and an inner diameter of 4 nm and an outer diameter of 30 nm with a ferromagnetic permalloy layer 30 are formed thereon. the thickness non-magnetic conductive Cu layer 14 of 10 nm, a nonmagnetic insulator SiO ₂ layer 13 having a thickness of 10 nm, a non-magnetic insulator SiO ₂ layer 13 of non-magnetic semiconductor GaAs layer 11 and the thickness of 30nm thickness 100nm is alternately A spin Hall effect layer made of a multilayer film is formed in a C shape with a notch end face. On the multilayer film, a ferromagnetic permalloy layer 30 is formed as a pillar having a diameter of 12 nm and a thickness of 20 nm at a position coaxial with the center of the ring. Copper electrode terminals 21 and 22 having a width of 1498 nm, a length of 50 nm, and a thickness of 100 nm are formed on the notch end face of the GaAS layer 11.

The ferromagnetic permalloy layer 30 is disposed so as to face a position close to the surface of the perpendicular magnetic recording medium 60 as shown in the sectional view of FIG. Here, the cross-sectional view of FIG. 18 is a cross-sectional view along AB indicated by a dotted line in the perspective schematic view of FIG. The magnetic shield 61 is provided between the permalloy layer 30 and the medium 60 so as to surround the medium 60 and the permalloy layer 30 in a ring shape around the local magnetic field detection device 311 formed on the side surface of the GaAs / SiO ₂ multilayer film. It consists of a flat plate to shield. The shielding flat plate is provided with an opening having a size equal to or smaller than the medium magnetic domain size on the ring center line of the local magnetic field detection device 311. The permalloy layer 30 is magnetized in the vicinity of the minute read magnetic domain of the medium 60 through the opening of the magnetic shield 61. By detecting the magnetization direction of the permalloy layer 30 with the local magnetic field detection device 311, it is possible to detect only the read magnetic domain of the medium 60. The symbol 40 in the figure indicates the direction of the current induced in the local magnetic field detection device 311. An arrow 55 indicates the direction of magnetization of the magnetic domains of the perpendicular magnetic recording medium 60. A white arrow 50 indicates the direction of the local magnetic field due to the leakage magnetic field from the medium detected using the local magnetic field detection device 311.

[Example 8]
FIG. 19 is a schematic cross-sectional view showing a configuration example of a magnetic reproducing head 3004 for detecting a leakage magnetic field from a perpendicular magnetic recording medium together with the magnetic recording medium. In this embodiment, the C-shaped local magnetic field detection device 311 shown in FIG. 16A is applied to a reproducing head for a perpendicular magnetic recording medium.

In the magnetic reproducing head 3004, a nonmagnetic insulator Al ₂ O ₃ layer 13 is formed on a base 63 made of a substrate, a base material, and the like, and an inner diameter of 4 nm is formed on the ferromagnetic permalloy layer 30. A nonmagnetic conductive Cu layer 14 having a diameter of 30 nm, a thickness of 10 nm, a nonmagnetic insulator Al ₂ O ₃ layer 13 having a thickness of 10 nm, a Pt layer 11 having a thickness of 4 nm, and a nonmagnetic insulator Al ₂ having a thickness of 10 nm. A multilayer film in which the O ₃ layers 13 are alternately stacked is formed in a C shape with a notch end face. Further, a ferromagnetic permalloy layer 30 is formed on the multilayer film as a pillar having a diameter of 5 nm and a thickness of 20 nm coaxially with the center of the ring. Cu electrodes 21 and 22 having a width of 13 nm, a length of 10 nm, and a thickness of 140 nm are formed at the side edges of the notch corresponding to both ends of the C-shape of the nonmagnetic Pt layer 11.

As shown in FIG. 19, the local magnetic field detection device 311 is arranged so that the side surface of the (Pt (4 nm) / Al ₂ O ₃ (10 nm)) ₁₀ laminated film is parallel to the surface of the perpendicular magnetic recording medium 60. The cross-sectional view of FIG. 19 is a cross-sectional view along AB indicated by a dotted line in the schematic perspective view of the local magnetic field detection device of FIG.

The magnetic shield 61 is composed of a portion surrounding the local magnetic field detection device 311 formed on the side surface of the Pt / Al ₂ O ₃ laminated film in a ring shape and a flat plate covering the portion. At a position close to the surface of the perpendicular magnetic medium 60 between the ferromagnetic permalloy layer 30 on the magnetic shield formed on the side surface of the Pt / Al ₂ O ₃ laminated film and the shielding flat plate, an opening smaller than the medium magnetic domain size is provided. Yes. The ferromagnetic permalloy layer 30 is magnetized by a leakage magnetic field from the magnetic domain of the perpendicular magnetic recording medium 60 that enters through the opening provided in the magnetic shield 61, and the magnetization is detected by the local magnetic field detection device 311. Thus, the leakage magnetic field from the recording magnetization of the perpendicular magnetic recording medium 60 can be detected.

  The symbol 40 in the figure indicates the direction of the current induced in the local magnetic field detection device 311. An arrow 55 indicates the direction of magnetization of the magnetic domains of the perpendicular magnetic recording medium 60. A white arrow 50 indicates the direction of the local magnetic field due to the leakage magnetic field from the medium detected using the local magnetic field detection device 311.

[Example 9]
FIG. 20 is a schematic cross-sectional view showing a configuration example of a magnetic reproducing head 3005 for detecting a leakage magnetic field from an in-plane magnetic recording medium together with the magnetic recording medium. This embodiment is an example in which the local magnetic field detection device 411 having an S-shape formed by connecting two partial rings shown in FIG. 21 is applied to the reproducing head for the in-plane magnetic medium 60. Here, the cross-sectional view of FIG. 20 is a cross-sectional view along the ACB indicated by a dotted line in the schematic perspective view of the local magnetic field detection device shown in FIG.

In the magnetic reproducing head 3005, a nonmagnetic insulator Al ₂ O ₃ layer 13 is formed on a substrate 63 made of a substrate, a base material, and the like, and an inner diameter of 2 is formed on the ferromagnetic permalloy layers 31 and 32. Two C-shaped nonmagnetic conductive Cu layers 14 and 15 having an outer diameter of 20 nm and an outer diameter of 10 nm and a thickness of 10 nm, an S-shaped nonmagnetic insulator Al ₂ O ₃ layer 13 having a thickness of 10 nm, A spin Hall effect layer composed of an S-shaped multilayer film in which a 5 nm thick Au layer 11 and a 5 nm thick nonmagnetic insulator Al ₂ O ₃ layer 13 are alternately laminated is formed. The portions of the ferromagnetic permalloy layers 31 and 32 that protrude from the spin Hall effect layer are needle-shaped having a diameter of 2 nm and a thickness of 20 nm, and are formed at positions coaxial with the center of the ring. Cu electrode terminals 21 and 22 having a width of 17.5 nm, a length of 10 nm, and a thickness of 5 nm are formed on the side surfaces of the non-magnetic Au layer 11 corresponding to both ends of the S-shape. The protruding portions of the ferromagnetic permalloy layers 31 and 32 are arranged at a distance such that they are magnetized in opposite directions by the leakage magnetic field from the magnetic domains recorded on the in-plane magnetic recording medium 60.

Further, as shown in FIG. 20, the local magnetic field detection device 411 is arranged so that the upper surface of the laminated film of the local magnetic field detection device 411 faces the medium 60 at a position close to the surface of the in-plane magnetic recording medium 60. The magnetic shield 61 is formed on the side surface of the Al ₂ O ₃ / Au multilayer film so as to surround the local magnetic field detection device 411 in a ring shape, and is provided between the local magnetic field detection device and the medium 60. It is comprised with the flat plate which shields a magnetic field detection device. In the shielding flat plate portion of the magnetic shield 61, an opening having a size equal to or smaller than the medium magnetic domain size is provided in a portion on a straight line extending vertically from the position C of the local magnetic field detection device 411 to the medium 60. Through the opening of the magnetic shield 61, a local magnetic field due to a leakage magnetic field from the read magnetic domain of the medium 60 is detected by focusing only on the read magnetic domain of the medium 60 with a local magnetic field detection device.

  A symbol 40 in FIG. 20 indicates the direction of the current induced in the local magnetic field detection device 411. An arrow 55 indicates the direction of magnetization of the magnetic domains of the in-plane magnetic recording medium 60. A white arrow 50 indicates the direction of the local magnetic field due to the leakage magnetic field from the medium detected using the local magnetic field detection device 411.

[Example 10]
FIG. 22 shows an example of the configuration of an integrated magnetic head 3006 for performing a magnetic recording by applying a recording magnetic field to a perpendicular magnetic recording medium, and detecting a leakage magnetic field from the minute magnetic domain of the medium and reading the magnetic recording. It is a cross-sectional schematic diagram shown with a magnetic recording medium. In this embodiment, a C-shaped local magnetic field generation detection device 511 in which the magnetic field generation unit 80 and the magnetic field detection unit 81 shown in FIG. 23 are connected via an insulator is used as an integrated magnetic recording / reproducing head for a perpendicular magnetic medium. It is an example applied to.

In the magnetic recording head 3006, a nonmagnetic insulator MgO layer 1300 having an inner diameter of 8 nm, an outer diameter of 3000 nm, and a thickness of 10 nm is formed on a base 63 made of a substrate and a base material, and an inner diameter of 8 nm, an outer diameter of 3000 nm, ₁₀ multilayers of nonmagnetic semiconductor GaAs layers 11w having a thickness of 100 nm and 10 nonmagnetic insulator MgO layers 1300 having an inner diameter of 8 nm, an outer diameter of 3000 nm, and a thickness of 10 nm alternately stacked (GaAs (100 nm) / MgO (10 nm)) A spin Hall effect layer 80 is formed. Copper electrode terminals 21 and 22 having a width of 1496 nm, a length of 50 nm, and a thickness of 1100 nm are formed on the cut end surface of the spin Hall effect layer 80. On the multilayer film, a nonmagnetic insulating MgO layer 1301 having a diameter of 3000 nm and a thickness of 10 nm is passed through a nonmagnetic conductive layer having an inner diameter of 20 nm, an outer diameter of 3000 nm, and a thickness of 10 nm. Cu layer 14, nonmagnetic insulator MgO layer 13r with an inner diameter of 20 nm, an outer diameter of 3000 nm, and a thickness of 10 nm, nonmagnetic semiconductor GaAs layer 11r with an inner diameter of 20 nm, an outer diameter of 3000 nm, and a thickness of 100 nm, an inner diameter of 20 nm, and an outer diameter of 3000 nm. Thus, ₁₀ spin-hole effect layers 81 made of ₁₀ multilayered non-magnetic insulator MgO layers 1302 having a thickness of 5 nm (GaAs (100 nm) / MgO (5 nm)) ₁₀ multi-layered are provided with a notch end face. Is formed. On the multilayer film, a ferromagnetic permalloy layer 30 is formed as a pillar having a diameter of 20 nm and a thickness of 20 nm at a position coaxial with the center of the ring. Copper electrode terminals 23 and 24 having a width of 1490 nm, a length of 50 nm, and a thickness of 1050 nm are formed on the cut end face of the spin Hall effect layer having the ferromagnetic permalloy layer 30.

  The ferromagnetic permalloy layer 30 is disposed so as to face a position close to the surface of the perpendicular magnetic recording medium 60 as shown in the sectional view of FIG. Here, the cross-sectional view of FIG. 22 is a cross-sectional view along AB shown by a dotted line in the schematic perspective view of FIG. The magnetic shield 61 is provided between the permalloy layer 30 and the medium 60 provided in a ring shape around the local magnetic field generation detecting device 511 formed on the side surface of the multilayer film of the spin Hall effect layers 80 and 81, and the medium 60. And a flat plate that shields the permalloy layer 30. In the shielding flat plate, an opening having a size smaller than or equal to the medium magnetic domain size is provided on the ring center line of the local magnetic field generation detecting device 511. From the opening of the magnetic shield 61, the local magnetic field generated in the magnetic field generating spin Hall effect layer 80 of the local magnetic field generation detecting device 511 and amplified by the permalloy layer 30 is applied only to the rewrite magnetic domain of the medium 60. Further, the permalloy layer 30 is magnetized in the vicinity of the minute read magnetic domain of the medium 60 through the opening of the magnetic shield 61. By detecting the magnetization direction of the permalloy layer 30 with the magnetic field detection spin Hall effect layer 81, the medium 60 can be detected by focusing only on a minute read magnetic domain.

The symbol 42 in FIG. 22 indicates the direction of the current flowing in the local magnetic field generation spin Hall effect layer 80 when the magnetic domain is rewritten, and the symbol 43 indicates the direction of the current induced in the local magnetic field detection spin Hall effect layer 81 when reading the magnetic domain. Indicates. An arrow 55 indicates the direction of magnetization of the magnetic domains of the perpendicular magnetic recording medium 60. The white arrow 50 indicates the direction of the local magnetic field generated in the local magnetic field generation spin Hall effect layer 80 at the time of magnetic domain rewriting, and the leakage magnetic field from the medium detected by the local magnetic field detection spin Hall effect layer 81 at the time of magnetic domain readout. Indicates the direction of the local magnetic field to be created. Further, when the magnetic domain is rewritten, the magnetic field H generated in the vicinity of the inner diameter of the local magnetic field generating spin Hall effect layer 80 magnetizes the permalloy layer 30 having a saturation magnetization Ms of 1.08 Tesla. B = μ ₀ H + Ms is the local magnetic field 50 generated from the magnetic recording head 3006. In this way, the strength of the generated magnetic field is increased by connecting the ferromagnetic permalloy layer 30. In addition, the soft magnetic layer 62 under the medium 60 prevents the magnetic field lines from spreading. The direction of the magnetization of the magnetic domain of the perpendicular magnetic recording medium 60 is reversed by the local magnetic field 50 generated from the magnetic field generating spin Hall effect layer 80 of the magnetic head 3006, and the leakage magnetic field of the micro magnetic domain of the medium 60 is detected by the local magnetic field detection spin hole. By detecting with the effect layer 81, the magnetization direction of the minute magnetic domain is read out.

[Example 11]
FIG. 24 shows an example of the configuration of another magnetic recording head 3007 for performing magnetic recording by applying a recording magnetic field to a perpendicular magnetic recording medium, and reading out a magnetic domain by detecting a leakage magnetic field of the medium. It is a cross-sectional schematic diagram shown with a recording medium. The present embodiment is another example in which the C-shaped local magnetic field generation detecting device 511 shown in FIG. 23 is applied to a magnetic head for perpendicular magnetic recording.

In the magnetic recording head 3007, a nonmagnetic insulating Al ₂ O ₃ layer having an inner diameter of 4 nm, an outer diameter of 30 nm, and a thickness of 5 nm is formed on a substrate 63 made of a substrate and a base material, and an inner diameter of 4 nm and an outer diameter of the nonmagnetic insulator. 10 Pt layers 11w with a thickness of 30 nm and a thickness of 4 nm and nonmagnetic insulator Al ₂ O ₃ layers 1300 with an inner diameter of 4 nm, an outer diameter of 30 nm and a thickness of 5 nm were alternately stacked (Pt (4 nm) / Al ₂ O ₃ (5 nm )) A spin Hall effect layer 80 composed of ₁₀ multilayers is formed in a C shape with a cut-out end face. Copper electrode terminals 21 and 22 having a width of 13 nm, a length of 30 nm, and a thickness of 90 nm are formed on the cut end face of the multilayer film. Further, on the multilayer film, a nonmagnetic insulating Al ₂ O ₃ layer 1301 having a diameter of 30 nm and a thickness of 10 nm is provided with an inner diameter of 8 nm and an outer diameter of 30 nm with the ferromagnetic permalloy layer 30. 10 nm nonmagnetic conductive Cu layer 14, inner diameter 8 nm, outer diameter 30 nm, nonmagnetic insulator Al ₂ O ₃ layer 10 nm thick, inner diameter 8 nm, outer diameter 30 nm, Pt layer 11 r 4 nm thick 10 nm non-magnetic insulator Al ₂ O ₃ layers 1302 are alternately stacked (Pt (4 nm) / Al ₂ O ₃ (10 nm)) C-shaped spin Hall effect layer 81 composed of ₁₀ multilayers with a notch end face Is formed. The ferromagnetic permalloy layer 30 is formed as a pillar having a diameter of 8 nm and a thickness of 20 nm at a position coaxial with the center of the ring. The notch end face of the spin Hall effect layer 81 having a ferromagnetic permalloy layer 30 (Pt (4 nm) / Al ₂ O ₃ (10 nm)) ₁₀ multilayer film has a width 13 nm, a length 10 nm, and a thickness 140 nm. Electrodes 23 and 24 are formed.

Further, as shown in FIG. 24, the local magnetic field generation detecting device 511 is arranged so that the side surface of the Pt / Al ₂ O ₃ laminated film is parallel to the surface of the perpendicular magnetic recording medium 60. The cross-sectional view of FIG. 24 is a cross-sectional view taken along AB indicated by a dotted line in the schematic perspective view of the local magnetic field generation detecting device of FIG. The magnetic shield 61 includes a portion surrounding the local magnetic field generation detecting device 511 formed on the side surface of the laminated film of the spin Hall effect layers 80 and 81 in an annular shape and a flat plate covering the portion. An opening smaller than the size of the medium magnetic domain is provided at a position close to the surface of the perpendicular magnetic medium 60 between the ferromagnetic permalloy layer 30 on the magnetic shield formed on the side surface of the spin Hall effect layers 80 and 81 and the shielding flat plate. ing. From the opening of the magnetic shield 61, the local magnetic field generated in the magnetic field generating spin Hall effect layer 80 of the local magnetic field generation detecting device 511 and amplified by the permalloy layer 30 is applied only to the rewrite magnetic domain of the medium 60. Further, the permalloy layer 30 is magnetized by the leakage magnetic field generated from the vicinity of the minute read magnetic domain of the medium 60 through the opening of the magnetic shield 61. By detecting the magnetization direction of the permalloy layer 30 with the magnetic field detection spin Hall effect layer 81, the medium 60 can be detected by focusing only on a minute read magnetic domain.

  24 indicates the direction of current flowing in the local magnetic field generating spin Hall effect layer 80 during magnetic domain rewriting, and symbol 41 indicates the direction of current induced in the local magnetic field detecting spin Hall effect layer 81 during magnetic domain reading. Indicates. An arrow 55 indicates the direction of magnetization of the magnetic domains of the perpendicular magnetic recording medium 60. The white arrow 50 indicates the direction of the local magnetic field generated in the local magnetic field generation spin Hall effect layer 80 at the time of magnetic domain rewriting, and the leakage magnetic field from the medium detected by the local magnetic field detection spin Hall effect layer 81 at the time of magnetic domain readout. Indicates the direction of the local magnetic field to be created.

When the magnetic domain is rewritten, the magnetic field H generated in the vicinity of the inner diameter of the local magnetic field generating spin Hall effect layer 80 magnetizes the permalloy layer 30 having a saturation magnetization Ms of 1.08 Tesla. μ ₀ H + Ms becomes the local magnetic field 50 generated from the magnetic recording head 3007. In this way, the strength of the generated magnetic field is increased by connecting the ferromagnetic permalloy layer 30. In addition, the soft magnetic layer 62 under the medium 60 prevents the magnetic field lines from spreading. The direction of the magnetization of the magnetic domain of the perpendicular magnetic recording medium 60 is reversed by the local magnetic field 50 generated from the magnetic field generating spin Hall effect layer 80 of the magnetic head 3007, and the leakage magnetic field of the micro magnetic domain of the medium 60 is detected by the local magnetic field detection spin hole. By detecting with the effect layer 81, the magnetization direction of the minute magnetic domain is read out.

[Example 12]
FIG. 25 shows an example of the configuration of an integrated magnetic head 3008 for performing magnetic recording by applying a recording magnetic field to an in-plane magnetic recording medium, and reading out magnetic recording by detecting a leakage magnetic field from a minute magnetic domain of the medium. 1 is a schematic cross-sectional view showing a magnetic recording medium together with In this embodiment, an S-shaped local magnetic field generation detection device 611 in which a magnetic field generation unit 80 having a shape in which two partial rings shown in FIG. 26 are connected and a magnetic field detection unit 81 are connected via an insulator, This is an example applied to an integrated magnetic recording / reproducing head for an in-plane magnetic medium. Here, the cross-sectional view of FIG. 25 is a cross-sectional view along the ACB indicated by the dotted line in the schematic perspective view of the local magnetic field generation detecting device shown in FIG.

In the magnetic recording head 3008, an S-shaped nonmagnetic insulator Al ₂ O ₃ layer having an inner diameter of 3 nm, an outer diameter of 20 nm, and a thickness of 10 nm is formed on a base 63 made of a substrate and a base material. Similarly, 10 S-shaped nonmagnetic Au layers 11 w having an inner diameter of 3 nm, an outer diameter of 20 nm, and a thickness of 5 nm and 10 S-shaped ferromagnetic FePt layers 12 having an inner diameter of 3 nm, an outer diameter of 20 nm, and a thickness of 10 nm are alternately stacked. (Au (5 nm) / FePt (10 nm)) A spin Hall effect layer 80 composed of ₁₀ multilayers is formed. Copper electrode terminals 21 and 22 having a width of 8.5 nm, a length of 20 nm, and a thickness of 150 nm are formed on the cut end face of the spin Hall effect layer 80. Further, on the spin Hall effect layer 80, an inner diameter of 3 nm centering on the ferromagnetic permalloy layers 31 and 32 via an S-shaped nonmagnetic insulator Al ₂ O ₃ layer 1301 having a diameter of 20 nm and a thickness of 10 nm. , Two C-shaped nonmagnetic conductive Cu layers 14 and 15 having an outer diameter of 20 nm and insulated from each other, a S-shaped nonmagnetic insulator Al ₂ O ₃ layer 13 having a thickness of 10 nm, A spin Hall effect layer composed of ₁₀ multilayers (Au (5 nm) / Al ₂ O ₃ (5 nm)) in which ₁₀ nm layers of 5 nm Au layers 11r and 5 nm thick nonmagnetic insulator Al ₂ O ₃ layers 1302 are alternately laminated. 81 is formed in an S shape with a notch end face. On the multilayer film, ferromagnetic permalloy layers 31 and 32 are formed as pillars having a diameter of 20 nm and a thickness of 20 nm at positions coaxial with the center of the ring. Copper electrode terminals 23 and 24 having a width of 8.5 nm, a length of 20 nm, and a thickness of 50 nm are formed on the cut-out end face of the spin Hall effect layer 81 having the ferromagnetic permalloy layers 31 and 32.

  Further, as shown in FIG. 25, the local magnetic field generation detection device 611 is arranged so that the upper surface of the laminated film of the local magnetic field generation detection device faces the medium 60 at a position close to the surface of the in-plane magnetic recording medium 60. The magnetic shield 61 is provided on the side surface of the laminated film of the spin Hall effect layers 80 and 81 and is provided between the local magnetic field generation detection device 611 and the medium 60, and a portion surrounding the local magnetic field generation detection device 611 in a ring shape. The medium 60 is composed of a flat plate that shields the local magnetic field generation detection device 611. In the shielding flat plate portion of the magnetic shield 61, an opening having a size equal to or smaller than the medium magnetic domain size is provided in a portion on a straight line extending vertically from the position C of the occurrence detection device 611 to the medium 60. A potential difference is applied to the copper electrode terminals 21 and 22 connected to the magnetic field generation spin Hall effect layer 80 of the local magnetic field generation detection device 611 from the opening of the magnetic shield 61, thereby being generated in the magnetic field generation spin Hall effect layer 80. The local magnetic field amplified by the permalloy layers 31 and 32 is applied only to the rewrite magnetic domain of the medium 60. Further, the permalloy layers 31 and 32 are magnetized by the leakage magnetic field generated from the vicinity of the minute read magnetic domain of the medium 60 through the opening of the magnetic shield 61. By detecting the magnetization directions of the permalloy layers 31 and 32 with the magnetic field detection spin Hall effect layer 81, the medium 60 can be detected by focusing only on a minute read magnetic domain.

  In FIG. 25, symbol 42 indicates the direction of current flowing in the local magnetic field generation spin Hall effect layer 80 during magnetic domain rewriting, and symbol 43 indicates the direction of current induced in the local magnetic field detection spin Hall effect layer 81 during magnetic domain reading. Indicates. An arrow 55 indicates the direction of magnetization of the magnetic domains of the in-plane magnetic recording medium 60. The white arrow 50 indicates the direction of the local magnetic field generated in the local magnetic field generation spin Hall effect layer 80 at the time of magnetic domain rewriting, and the leakage magnetic field from the medium detected by the local magnetic field detection spin Hall effect layer 81 at the time of magnetic domain readout. Indicates the direction of the local magnetic field to be created.

At the time of magnetic domain rewriting, spin electrons having different polarities are separately accumulated inside two curves of the S-shaped local magnetic field generating spin Hall effect layer 80. When the conduction electron density of the nonmagnetic Au layer 11w of the local magnetic field generation spin Hall effect layer 80 is 10 ²³ cm ⁻³ and α _H is 0.01, the local magnetic field 50 is H, and μ ₀ H to 0.74 Tesla. . Since the local magnetic field 50 magnetizes the permalloy layers 31 and 32 having a saturation magnetization Ms of 1.08 Tesla, the magnetic flux density B = μ ₀ H + Ms inside the permalloy layer 30 becomes the local magnetic field 50 generated from the magnetic recording head 3008. The magnetization direction of the magnetic domain of the in-plane magnetic recording medium 60 can be reversed. At this time, the magnetic field H generated in the vicinity of the two inner diameters of the local local magnetic field generating spin Hall effect layer 80 magnetizes the ferromagnetic layers 31 and 32 having the saturation magnetization Ms in the opposite directions. Magnetic flux density B = ± (μ ₀ H + Ms) having different polarities in FIG. 3 generates a local magnetic field 50 parallel to the medium surface. By connecting the ferromagnetic layer to the spin Hall effect element, the intensity of the generated magnetic field increases. The direction of magnetization of the magnetic domain of the perpendicular magnetic recording medium 60 is reversed by the local magnetic field 50 generated from the magnetic field generating spin Hall effect layer 80 of the magnetic head 3008, and the leakage magnetic field of the micro magnetic domain of the medium 60 is detected by the local magnetic field detection spin hole. By detecting with the effect layer 81, the magnetization direction of the minute magnetic domain is read out. The configuration of the S-shaped local magnetic field generation detection device of the present embodiment is not limited to a structure in which two C-shaped partial rings are connected, and a structure in which two or more plural pieces are connected may be used.

[Example 13]
FIG. 27 shows a schematic configuration of a magnetic disk apparatus using the magnetic head according to the present invention. The magnetic disk apparatus includes a magnetic disk 1601 having concentric tracks, a driving motor 1603 that supports and rotates the magnetic disk 1601 by a rotating shaft 1602, and a magnetic head that records or reproduces data on the magnetic disk 1601. A slider 1606 on which 1610 is mounted, an actuator unit 1611 that supports the slider 1606 and moves the magnetic head 1610 to a predetermined track on the magnetic disk 1601, and data reproduction / decoding for transmitting / receiving data read / written by the magnetic head 1610 The system 1613 includes an actuator 1611 and a controller 1612 including a controller 1614 for controlling the driving motor 1603. The magnetic head 1610 is the magnetic recording head, magnetic reproducing head, or recording / reproducing integrated magnetic head of the present invention described so far.

  Simultaneously with the rotation of the magnetic disk 1601, the slider 1606 moves on the disk surface, thereby accessing a predetermined track position where the target data is recorded. The slider 1606 is attached to the arm 1608 by a suspension 1607. The suspension 1607 has a slight elasticity, and makes the slider 1606 adhere to the magnetic disk 1601. The arm 1608 is attached to the actuator 1611. The actuator 1611 is configured by a voice coil motor (VCM). The VCM 1611 is composed of a movable coil placed in a fixed magnetic field, and the moving direction and moving speed of the coil are controlled by an electric signal supplied from the control means 1614 via the line 1604.

  During the operation of the magnetic disk device, rotation of the magnetic disk 1601 causes an air bearing due to an air flow between the slider 1606 and the disk surface, which causes the slider 1606 to float from the surface of the magnetic disk 1601. Therefore, during the operation of the magnetic disk device, the air bearing balances with the slight elastic force of the suspension 1607, and the slider 1606 is kept in contact with the surface of the magnetic disk and floating at a certain distance from the magnetic disk 1601. Is done. Usually, the control means 1614 includes a logic circuit, a memory, a microprocessor, and the like. The control means 1614 transmits and receives control signals via each line and controls various constituent means of the magnetic disk device. For example, motor 1603 is controlled by a motor drive signal transmitted via line 1605. The actuator 1611 is controlled so as to optimally move and position the selected slider 1606 to the target data track on the associated magnetic disk 1601 by a head position control signal and a seek control signal via the line 1604. . Then, the data reproducing / combining system 1613 receives and decodes the electric signal obtained by reading and converting the data on the magnetic disk 1601 by the magnetic head 1610 via the line 1609. In addition, an electric signal for writing as data on the magnetic disk 1601 is transmitted to the magnetic head 1610 via the line 1609. That is, the data reproduction / complex system 1613 controls transmission / reception of information read or written by the magnetic head 1610.

  Note that the above-described read and write signals may be transmitted directly from the magnetic head 1610. Control signals include, for example, an access control signal and a clock signal. Further, the magnetic disk device may include a plurality of magnetic disks, actuators, and the like, and the actuator may include a plurality of magnetic heads. In addition to the type that the disk type magnetic medium rotates and the magnetic head accesses as shown in the figure, the medium is also the same as the mechanism in which a large number of magnetic heads scan on the fixed medium in parallel. It is effective for. By combining such a plurality of mechanisms, a so-called disk array device can be formed.

  By using this apparatus, spin can be efficiently accumulated in a minute region, and a magnetic local field having an effective useful strength can be realized, and magnetization of the minute region can be detected.

DESCRIPTION OF SYMBOLS 11 ... Nonmagnetic spin Hall effect layer 12 ... Ferromagnetic layers 1300, 1301, 1302 ... Nonmagnetic insulator layers 14, 15 ... Nonmagnetic conductive layers 21, 22, 23, 24 ... Electrode terminals 30, 31, 32 ... Strong Magnetic layers 40, 42, 43 ... Current 50, 51 ... Local magnetic field 52 ... Upward spin electrons 53 ... Downward spin electrons 60 ... Magnetic recording medium 61 ... Magnetic shield 62 ... Soft magnetic layer 63 ... Substrate 70 ... Power supply 71 ... Voltmeter 80 ... Local magnetic field generation spin Hall effect layer 81 ... Local magnetic field detection spin Hall effect layer 110, 113, 120, 123, 210, 215, 220, 224, 800, 410, 311, 411, 511, 611 ... Spin Hall effect element 1000, 2000: Local magnetic field generation devices 310, 1100, 2100 ... Local magnetic field detection devices 3000 to 3008 ... Magnetic recording heads

Claims (16)

A spin Hall effect element including a spin Hall effect layer made of a nonmagnetic material and having a curved portion;
A pair of electrode terminals for passing current through the spin Hall effect element;
A power source connected to the pair of electrode terminals,
The spin Hall effect layer has a partial ring with a part cut away, or a shape in which a plurality of the partial rings are connected,
A local magnetic field generating device characterized in that a magnetic field is generated by polarized spin electrons accumulated in a curved inner region of the bending portion while a current is passed through the spin Hall effect element .   2. The local magnetic field generating device according to claim 1, wherein the spin Hall effect element includes a laminated film in which the spin Hall effect layer and a ferromagnetic layer are laminated, and the thickness of the spin Hall effect layer is the spin Hall effect layer. A local magnetic field generating device characterized in that it is not more than twice the spin diffusion length of the material constituting the material. 3. The local magnetic field generating device according to claim 2 , further comprising a high resistance film between the spin Hall effect layer and the ferromagnetic layer. In the local magnetic field generating device according to claim 3, the local magnetic field generating device, wherein the high-resistance film is AlO _X.   2. The local magnetic field generating device according to claim 1, wherein the spin Hall effect element includes a stacked film in which a ferromagnetic layer is tunnel-junctioned to the spin Hall effect layer through a nonmagnetic insulating layer. Magnetic field generating device. 6. The local magnetic field generating device according to claim 5 , wherein the nonmagnetic insulating layer is made of magnesium oxide MgO.   2. The local magnetic field generating device according to claim 1, wherein the width of the spin Hall effect layer is wider than three times the spin diffusion length of the material constituting the spin Hall effect layer.   2. The local magnetic field generating device according to claim 1, wherein the spin Hall effect layer is a nonmagnetic element having an atomic number larger than Cu, or gallium arsenide, indium arsenide, aluminum arsenide, indium gallium arsenide, indium gallium nitrogen-gallium nitrogen superlattice. A compound semiconductor selected from the group consisting of mercury telluride, mercury selenide, β-hydrogen sulfide, α-tin, lead telluride, lead selenide and lead sulfide, or a gallium arsenide based semiconductor A local magnetic field generating device.   2. The local magnetic field generating device according to claim 1, wherein the spin Hall effect element has a shape composed of one partial ring with a part cut away, and generates a magnetic field in a direction perpendicular to the film surface of the spin Hall effect element. A local magnetic field generating device characterized by that.   2. The local magnetic field generating device according to claim 1, wherein the spin Hall effect element has a shape in which two partial rings with a part cut away are connected, and generates a magnetic field in a direction parallel to a film surface of the spin Hall effect element. A local magnetic field generating device characterized by being made to cause.   2. The local magnetic field generating device according to claim 1, wherein a ferromagnetic layer is disposed on the curved portion of the spin Hall effect element via a nonmagnetic insulating layer. 12. The local magnetic field generating device according to claim 11 , wherein the ferromagnetic layer is an element selected from the group consisting of Co, Ni and Fe, or an alloy or compound containing at least one of them as a main component. A local magnetic field generating device comprising: A spin Hall effect element including a spin Hall effect layer made of a nonmagnetic material and having a curved portion;
A pair of electrode terminals for passing current through the spin Hall effect element;
A power source connected to the pair of electrode terminals;
Have a magnetic shield having an opening for applying the curved portion magnetic field generated by the polarized spin electrons accumulated in the curved inner area of the spin Hall effect device a magnetic recording medium,
The spin Hall effect layer has a shape consisting of one partial ring with a part cut away,
A magnetic recording head, wherein a magnetic field in a direction perpendicular to a film surface of the spin Hall effect element is generated while a current is passed through the spin Hall effect element . A spin Hall effect element comprising a non-magnetic spin Hall effect layer, a nonmagnetic insulator layer, and a laminated film in which a nonmagnetic conductive layer is laminated, and having a curved portion;
A ferromagnetic core disposed in a curved inner region of the curved portion;
Means for applying a current from the non-magnetic conductive layer to the ferromagnetic core;
A pair of electrode terminals connected to both ends of the spin Hall effect layer,
The spin Hall effect layer has a partial ring with a part cut away, or a shape in which a plurality of the partial rings are connected,
While applying a current from the nonmagnetic conductive layer to the ferromagnetic core, the polarized spin electrons injected from the ferromagnetic core into the spin Hall effect layer according to the magnetization state of the ferromagnetic core A local magnetic field detection device that detects a voltage generated between a pair of electrodes. A spin Hall effect element comprising a non-magnetic spin Hall effect layer, a nonmagnetic insulator layer, and a laminated film in which a nonmagnetic conductive layer is laminated, and having a curved portion;
A ferromagnetic core disposed in a curved inner region of the curved portion;
Means for applying a current from the non-magnetic conductive layer to the ferromagnetic core;
A pair of electrode terminals connected to both ends of the spin Hall effect layer;
Have a magnetic shield having an opening for introducing the leakage magnetic field from the magnetic recording medium to the ferromagnetic core,
The spin Hall effect layer has a shape composed of one partial ring with a part cut away, and is perpendicular to the film surface of the spin Hall effect element while applying a current from the nonmagnetic conductive layer to the ferromagnetic core. A magnetic reproducing head characterized by detecting a magnetic field in any direction . A first spin Hall effect element having a first spin Hall effect layer made of a non-magnetic material and having a curved portion, a pair of electrode terminals for passing a current through the first spin Hall effect element, and the pair of electrode terminals A local magnetic field generating device that generates a magnetic field by polarized spin electrons accumulated in a curved inner region of the bending portion while passing a current through the spin Hall effect element ,
A second spin Hall effect element comprising a second spin Hall effect layer made of a nonmagnetic material, a nonmagnetic insulator layer, and a nonmagnetic conductive layer and having a curved portion, and a curved inner side of the curved portion A ferromagnetic core disposed in a region, means for applying a current from the nonmagnetic conductive layer to the ferromagnetic core, and a pair of electrode terminals connected to both ends of the second spin Hall effect layer Polarized spin electrons injected from the ferromagnetic core into the spin Hall effect layer according to the magnetization state of the ferromagnetic core while applying a current from the nonmagnetic conductive layer to the ferromagnetic core A local magnetic field detection device for detecting a voltage generated between the pair of electrodes by:
A nonmagnetic insulator layer disposed between the local magnetic field generating device and the local magnetic field sensing device;
Wherein the magnetic field generated from the local magnetic field generating device is applied to the magnetic recording medium, have a magnetic shield having an opening for introducing the leakage magnetic field from the magnetic recording medium to the local magnetic field sensing device,
The first and second spin Hall effect layers have a shape made of one partial ring with a part cut away, and the local magnetic field generating device is in a direction perpendicular to the film surface of the first spin Hall effect element. An integrated recording / reproducing magnetic head characterized by generating a magnetic field, wherein the local magnetic field detecting device detects a magnetic field in a direction perpendicular to the film surface of the second pinhole effect element .

Images