JP2016018574A - Magnetic recording medium device, magnetic recording / reproducing method, spatial light modulator, and pixel driving method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of reducing a magnitude of a pulse current which causes data stored as a magnetic domain to intermittently shift-move in a thin line direction in recording and reproduction of a magnetic recording medium that uses a magnetic thin wire as a track that is a data recording area.SOLUTION: A magnetic recording reproduction method alternately and intermittently executes in a stop period and a peak period of a pulse current a step of magnetizing a designated area of a magnetic thin wire or detecting the magnetism of this designated area and a magnetic zone moving step of moving a magnetic zone formed in the magnetic thin wire by a length of one portion of data, by supplying a pulse current to the magnetic thin wire of a magnetic recording medium 10, thereby recording or reproducing data in order with respect to this magnetic thin wire. The magnetic zone can be moved in the magnetic zone moving step by executing these steps, while vertically applying a magnetic field H with coils 80 and 80 vertically provided on the magnetic recording medium 10 even when a current density of a scan current Isc that is a peak current of a pulse current is small.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a magnetic recording medium device and a magnetic recording / reproducing method for recording or reproducing data on a magnetic recording medium having a magnetic thin line formed by forming a magnetic substance in a thin line as a track, or a magneto-optical type having a magnetic thin line as a pixel array. This relates to a spatial light modulator.

  In storage devices such as hard disk drives (HDD), with the increase in the amount of information to be handled, higher recording density and higher speed of recording and reproduction are being promoted. As the recording density is increased, the tracks of recording media such as magnetic disks used for HDDs are narrowed, and the length of one data (1 bit) in the track is shortened. In order to detect magnetism, the recording / reproducing system is a magnetic system using a magnetic head composed of a magnetoresistive element such as a GMR (Giant MagnetoResistance) element or a TMR (Tunnel MagnetoResistance) element, or A magneto-optical method using laser light irradiation is applied.

  Recording and reproduction on such a magnetic disk are carried out along the track (in the circumferential direction of the disk) by rotating the disk with a spindle motor and moving the magnetic head or the laser beam irradiation spot only in the radial direction of the disk. ) Magnetize (record) in a predetermined magnetization direction or detect (reproduce) magnetism. In order to increase the speed of recording and reproduction in such a disc, firstly, the rotational speed of the disc is increased. However, there is a limit to increasing the rotational speed due to problems such as the time required for track magnetization during recording, the time required for magnetic detection during reproduction, and malfunctions due to disk vibration.

  Therefore, as a method of moving recorded data without driving the recording medium, Patent Document 1 discloses that a track is formed by forming a thin wire-like magnetic body (hereinafter appropriately magnetic thin wire) into a U-shape or the like. A memory device is disclosed. This is because when a magnetic material is formed in a thin wire shape, magnetic domains are generated in the length direction, and when a current is further supplied in the length direction, all the domain walls generated to separate the magnetic domains are the length of the magnetic wire. This utilizes a characteristic of performing shift movement of moving in the same distance in the direction (see Non-Patent Documents 1 and 2). That is, each magnetic head for recording and reproduction is fixed to a predetermined location (a U-shaped top portion in Patent Document 1) on a track (magnetic wire), and a current is reversibly supplied from both ends of the track to provide a domain wall. The desired magnetic domain sandwiched between the magnetic heads is moved to a position facing the magnetic head.

  Patent Documents 2 to 4 disclose a magnetic recording medium in which a plurality of magnetic thin wires are formed concentrically like a track such as a current magnetic disk. The method for recording and reproducing data on these magnetic recording media varies depending on the shape of the magnetic material (line width, etc.) and the current density of the supplied current, but the moving speed of the domain wall is several tens m / s to about 250 m / s. It is expected to exceed the reproduction speed due to the rotation of the current disc because it is extremely high as s.

  In addition, a spatial light modulator in which a plurality of magnetic thin wires are arranged in parallel by using a single magnetic thin wire as a plurality of pixels (pixel row) continuous in a row can be provided (see Patent Document 5). Such a spatial light modulator cannot individually rewrite data (bright / dark) pixel by pixel, but because the moving speed of the domain wall is extremely high, more than 1000 pieces of magnetic thin wire can be used. Rewriting to a pixel can be performed in a sufficiently short time.

US Pat. No. 6,834,005 JP 2011-1000051 A JP 2011-123943 A JP 2012-84206 A JP 2012-128396 A

T. Koyama et al., “Control of Domain Wall Position by Electrical Current in Structured Co / Ni Wire with Perpendicular Magnetic Anisotropy”, Applied Physics Express 1, 101303 (2008) Xin Jiang et al., “Enhanced stochasticity of domain wall motion in magnetic racetracks due to dynamic pinning”, Nature Communications, 1, pp.1-5 (2010)

T. Koyama et al., “Current-induced magnetic domain wall motion below intrinsic threshold triggered by Walker breakdown”, Nature Nanotechnology Vol.7, pp.635-639 (2012)

  In recording and reproducing data on a magnetic recording medium, it is required to save more power. However, in the magnetic recording medium and the spatial light modulator described in Patent Documents 1 to 5, data shift shift is required. Therefore, it is necessary to supply a current (scanning current) of a predetermined current density or more to the magnetic thin wire according to the material or the like. However, since the current required for data shift movement has a relatively high current density, if such a current is continuously supplied, the magnetic wire may be deteriorated, and the life of the magnetic recording medium is shortened. Further, since current is required not only for data writing but also for data movement, more current is consumed. One way to reduce the scanning current is to reduce the cross-sectional area of the magnetic wire. However, for data storage (magnetization retention), reproduction (magnetism detection), processing accuracy, etc. However, since the current density remains high, deterioration of the magnetic wire is not suppressed.

  The present invention was devised in view of the above problems, and relates to a magnetic recording medium device and a magnetic recording / reproducing method for a recording medium in which a track is formed by the magnetic thin wire, and a spatial light modulator in which a pixel row is formed by a magnetic thin wire. It is an object to provide a device that can reduce the current supplied for data shift movement.

  In order to solve the above-mentioned problems, the present inventors have come up with the idea of using a phenomenon (see Non-Patent Document 3) in which a domain wall moves when a magnetic field is applied to a magnetic wire with a lower current density. . That is, the magnetic recording medium device according to the present invention includes a magnetic thin line formed by forming a magnetic film having perpendicular magnetic anisotropy into a thin line shape, and binary data is changed to one of two different magnetization directions. In this configuration, binary data is recorded or reproduced on a magnetic recording medium that is continuously recorded in the direction of the fine magnetic wire. The magnetic recording medium device includes a magnetizing unit that magnetizes a designated area provided at a position designated in advance in the magnetic wire in one of the two magnetization directions based on binary data, and a magnetization direction in the designated area Current supply means for supplying a pulse current for intermittently moving a magnetic wall separating the magnetic domains formed in the magnetic fine wire in the direction of the fine wire, and at least one of magnetic detection means for detecting the magnetic fine wire; and Magnetic field applying means for applying a magnetic field of a magnitude that does not change the direction of magnetization in the vertical direction or the thin wire width direction of the magnetic thin wire, and the magnetic field applying means to the magnetic thin wire to which the pulse current is supplied, The magnetic field is applied at least in a peak period of the pulse current.

  With such a configuration, since a magnetic field is applied to the magnetic wire, a magnetic recording medium device in which the domain wall moves with a smaller current can be obtained.

  Further, another magnetic recording medium device according to the present invention is a device for recording or reproducing binary data on the magnetic recording medium, wherein a designated area provided at a position designated in advance in the magnetic thin wire, At least one of a magnetizing unit that magnetizes in one of the two magnetization directions based on binary data and a magnetic detecting unit that detects the magnetization direction in the specified region, and the magnetic thin wire are formed on the magnetic thin wire, respectively. Current supply means for supplying a pulse current for intermittently moving the magnetic domain wall separating the magnetic domains in the direction of the thin line, wherein the current supply means is an object of operation by the magnetization means or the magnetic detection means The pulse current is supplied to one of the magnetic wires in one direction, and at the same time, the pulse current is supplied to one or both of the adjacent magnetic thin wires, and the pulse current is supplied Characterized in that it does not supply the same direction in the magnetic wire between the serial neighboring.

  With such a configuration, since a magnetic field is applied from the adjacent magnetic wire, a magnetic recording medium device can be provided in which a magnetic field is applied to the magnetic wire without providing a magnetic field applying unit.

  The magnetic recording / reproducing method according to the present invention includes a magnetic thin line formed by forming a magnetic film having perpendicular magnetic anisotropy into a thin line shape, and converts the binary data into one of two different magnetization directions. This is a method of recording or reproducing binary data on a magnetic recording medium that is continuously recorded in the direction of fine lines. In this magnetic recording / reproducing method, by supplying to the magnetic thin wire a pulse current in which the magnetic domains formed in the magnetic thin wire move intermittently together with the domain walls that delimit the magnetic domain, A magnetic domain moving step is performed in which a magnetic domain formed in the magnetic thin line is moved by a distance corresponding to the length of one of the data in the thin line direction, and when the current in the pulse current is stopped, the magnetic thin line is moved to a position designated in advance. A magnetization step of magnetizing a specified region provided in one of the two magnetization directions based on binary data, or a magnetic detection step of detecting a magnetization direction in the specified region, and performing the magnetization step or the magnetic detection step And the magnetic domain moving step are alternately repeated to record or reproduce data in order for the magnetic thin wires. At least in the magnetic domain moving step, a magnetic field having a magnitude that does not change the magnetization direction of the magnetic wire is applied to the magnetic wire in the vertical direction or the width direction of the magnetic wire.

  By such a procedure, a magnetic field is applied to the magnetic wire, so that the domain wall can be moved with a smaller current.

  Another magnetic recording / reproducing method according to the present invention is a method for recording or reproducing binary data on the magnetic recording medium, wherein a selection step of selecting one or more magnetic wires from the magnetic recording medium is performed. By supplying a pulse current in which the magnetic domains formed in the magnetic thin wire move intermittently together with the domain walls that delimit the magnetic domain to the selected magnetic thin wire, the magnetic thin wire is formed at the time of current supply in the pulse current. A magnetic domain moving step is performed in which the magnetic domain is moved by a distance corresponding to the length of one of the data in the direction of the thin line, and at the time of stopping the current in the pulse current, each of the selected magnetic thin lines is placed at a predetermined position. A magnetization step of magnetizing a specified area provided in one of the two magnetization directions based on binary data, or detecting a magnetization direction in the specified area Subjected to gas-detection step, the magnetizing step or the repeatedly performs magnetic detection step and the magnetic domain moving step alternately, the recording or reproducing data sequentially on the selected magnetic wire. The pulse current is supplied to one of the selected magnetic wires in one direction, and at the same time, the pulse current is supplied to one or both of the magnetic wires adjacent to the one magnetic wire, and the pulse current is supplied. The two adjacent magnetic wires are not supplied in the same direction.

  By such a procedure, a magnetic field is applied from the adjacent magnetic wire, so that a magnetic field can be applied to the magnetic wire without providing a magnetic field applying means.

  A spatial light modulator according to the present invention includes the magnetic recording medium device according to the present invention and the magnetic recording medium, and a plurality of magnetic thin wires arranged in parallel on the magnetic recording medium is a pixel array in which pixels are two-dimensionally arranged. .

  The pixel driving method of the spatial light modulator according to the present invention is a pixel array in which a plurality of magnetic thin wires formed by forming a magnetic film having perpendicular magnetic anisotropy in a thin line shape are arranged in parallel and the pixels are arranged in a matrix. In the spatial light modulator, the magnetic recording / reproducing method according to the present invention causes each pixel of the pixel array to have one of two different magnetization directions based on binary data input to the pixel. .

  According to the magnetic recording medium device and the magnetic recording / reproducing method of the present invention, the deterioration of the magnetic recording medium using the magnetic thin wire as a track is suppressed, and recording / reproducing can be performed with power saving. According to the spatial light modulator of the present invention, bright / dark writing can be performed with low power consumption in each pixel of a pixel array composed of a large number of magnetic thin wires.

1 is an external view showing a configuration of a magnetic recording medium device according to a first embodiment of the present invention. 1A and 1B are schematic views of a magnetic recording medium in which data is recorded / reproduced by the magnetic recording medium device according to the first embodiment of the present invention, where FIG. 1A is a plan view and FIG. 1B is a partially enlarged view of FIG. . It is a schematic diagram explaining the structure of the magnetic fine wire of the magnetic recording medium mounted in the magnetic recording medium apparatus based on this invention. It is an external view which shows the structure of the magnetic-recording-medium apparatus which concerns on the modification of 1st Embodiment of this invention. 4A and 4B are schematic views of a magnetic recording medium on / from which data is recorded / reproduced by the magnetic recording / reproducing method according to the second embodiment of the present invention, where (a) is an exploded perspective view and (b) is a partial sectional view along the radial direction. is there. 4A and 4B are schematic views of a magnetic recording medium on / from which data is recorded / reproduced by a magnetic recording / reproducing method according to a third embodiment of the present invention, where (a) is a cross-sectional view and (b) is a perspective view. It is a graph showing the distance dependence from the said magnetic fine wire of the magnetic field which generate | occur | produces from the magnetic fine wire through which a constant current flows. (A), (b) is an exploded perspective view of a modified example of a magnetic recording medium in which data is recorded / reproduced by the magnetic recording / reproducing method according to the third embodiment of the present invention. It is sectional drawing of the magnetic recording medium on which data is recorded / reproduced by the magnetic recording / reproducing method concerning 4th Embodiment of this invention and its modification, (a) is 4th Embodiment, (b), (c). Is a modification. FIG. 9 is a schematic diagram of a magnetic recording medium on / from which data is recorded / reproduced by a magnetic recording / reproducing method according to a fifth embodiment of the present invention, where (a) is a perspective view and (b) is a cross-sectional view. FIG. 2 is a schematic diagram of a spatial light modulator in which writing is performed on a pixel by a pixel driving method of the spatial light modulator, where (a) is a perspective view and (b) is a cross-sectional view.

  Hereinafter, embodiments for realizing a magnetic recording medium device and a magnetic recording / reproducing method, a spatial light modulator, and a pixel driving method thereof according to the present invention will be described with reference to the drawings. The magnetic recording medium apparatus and the magnetic recording / reproducing method according to the present invention both record and reproduce data by providing a magnetic thin line formed by forming a magnetic substance in a thin line as a data recording (storage) area. By moving the domain wall by supplying a current to the magnetic wire, the stored data is moved in the magnetic wire as a magnetic domain. The spatial light modulator according to the present invention is a pixel array in which a plurality of the magnetic thin wires are arranged in parallel.

[First Embodiment]
The magnetic recording medium device according to the first embodiment of the present invention includes magnetic field applying means for applying a magnetic field to the entire magnetic recording medium. Specifically, as shown in FIG. 1, the magnetic recording medium device 20 is a magnetic recording / reproducing device that is opposed to a predetermined region of the magnetic wires 1, 1,... (See FIG. 2) formed on the magnetic recording medium 10. An apparatus 50; coils (magnetic field applying means) 80, 80 disposed above and below the magnetic recording medium 10; and a power source (coil power source, magnetic field generating current source) 9 for supplying current to the coils 80, 80. Prepare.

(Magnetic recording medium)
First, a magnetic recording medium in which data is recorded and reproduced by the magnetic recording medium device and the magnetic recording / reproducing method according to the first embodiment of the present invention (hereinafter referred to as the magnetic recording medium according to the first embodiment of the present invention as appropriate). The same applies to the second and subsequent embodiments). As shown in FIGS. 2A and 2B, the magnetic recording medium 10 according to the first embodiment of the present invention is similar to the magnetic recording medium (magnetic disk) described in Patent Documents 2 to 5, as shown in FIGS. A magnetic thin wire 1 formed by forming a magnetic material in a thin line shape on a circular ring-shaped substrate 2 is provided as a data recording (storage) area. In this magnetic thin wire 1, binary data, that is, "0" or "1" data is converted into one of two different magnetization directions, that is, a magnetic domain in an upward or downward magnetization direction as shown in FIG. To be recorded. 2B is a partially enlarged view of FIG. 2A and shows a portion including both ends of the four magnetic wires 1 on the outermost periphery of the magnetic recording medium 10. FIG.

  In the magnetic recording medium 10, the magnetic thin wires 1, 1,... Are concentrically formed on the substrate 2 with the insulating layer 4 interposed therebetween in plan view. Specifically, the single magnetic wire 1 is formed in a C shape lacking a part of the ring in plan view. Furthermore, the magnetic recording medium 10 includes an electrode 31 and an electrode 32 (referred to as a positive electrode 31 and a negative electrode 32 as appropriate) connected to one end and the other end of the magnetic wire 1. In FIG. 3, only one of the magnetic thin wires 1 in the magnetic recording medium 10 is shown in a straight line for the sake of brevity.

(Magnetic wire)
The magnetic wire 1 is formed by forming a magnetic body (magnetic material) into a thin wire shape that is sufficiently long with respect to the thickness and width. Specifically, if the magnetic thin wire 1 has a thickness (film thickness) of 70 nm or less and a width (thin wire width) of 300 nm or less, it is preferable because the magnetic domains are easily divided only in the thin wire direction. Further, the magnetic recording medium 10 can have a higher recording density as the pitch of the magnetic wire 1 is narrower, that is, the width is smaller (thin). On the other hand, for data storage (magnetization retention), it is preferable that the magnetic wire 1 has a certain thickness and width. Specifically, the thickness is preferably 5 nm or more and the width is preferably 10 nm or more. In addition, including other embodiments described later, the thickness of the magnetic fine wire is the thickness at a portion where the upper and lower surfaces are flat except for a deformed portion such as a recess 1 trp (see FIGS. 2B and 3) described later. Refers to In addition, when the thickness and width are larger than the above ranges, the magnetic fine wire may be generated in plural by dividing the magnetic domain in the fine wire width direction or the like, but by applying an external magnetic field in advance, only the fine wire direction can be obtained. The magnetic domain can be divided into two.

  The magnetic wire 1 has a thin wire shape (plan view shape) that is a straight line that is not bent or a curve that is sufficiently gentle with respect to the thickness and width. In the magnetic recording medium 10 whose outer shape is a disk shape as in the present embodiment, the magnetic fine wire 1 becomes a sufficiently long and gentle curve by forming a shape along the circumference of the concentric circle with the outer shape. The outer diameter of the magnetic recording medium 10 can be made longer, and the magnetic recording medium 10 can be efficiently arranged on the entire upper surface of the magnetic recording medium 10 to increase the recording density. Therefore, the magnetic wire 1 does not need to have the same thin wire length in the magnetic recording medium 10, and the magnetic wire 1 is longer as it is provided closer to the outer periphery, so that the data recording area (capacity) as a whole of the magnetic recording medium 10 is increased. Should be increased. Further, the magnetic recording medium is not limited to a disk shape, and may be a plate having a rectangular shape in plan view, for example, as in a magnetic recording medium 10A (see FIG. 4) in a modified example described later. What is necessary is just to form in a shape.

  The magnetic wire 1 is formed of a magnetic material in the same manner as a recording layer of a general magnetic disk, and it is preferable to apply a perpendicular magnetic anisotropic material suitable for miniaturization. Further, a material having a certain degree of coercive force is applied so that the magnetization direction does not change even when a magnetic field of about several tens to several hundreds Oe is applied from the coils 80 and 80. As such a material, a known ferromagnetic material can be applied. Specifically, a multilayer film such as a Co / Pd multilayer film in which transition metals such as Co and any one of Pd, Pt, and Cu are alternately laminated. In addition, an alloy (RE-TM alloy) of a rare earth metal such as Tb—Fe—Co, Gd—Fe and a transition metal can be used. These materials are formed into a film by a known method such as a sputtering method, and are formed into the above-described thin wire shape by photolithography and etching or lift-off method to form the magnetic wire 1.

  In the magnetic recording medium 10, as shown in FIGS. 2 (b) and 3, the magnetic thin wire 1 is set in the vicinity of both ends (connection portions with the electrodes 31 and 32) as a reproduction area 1r and a writing area 1w. The area between 1r and 1w is a data storage area. Further, the magnetic thin wire 1 has a recess 1trp whose top surface is locally thin so that the data storage area is divided into bit lengths (unit length) Lb so that the cross-sectional view is V-shaped or U-shaped. Preferably it is formed. Since the domain wall generated between the areas (magnetic domains) in which different data (“1”, “0”) are stored is locked by the recess 1 trp, even if a slight shift occurs in the shift movement of the data, it is corrected. The Here, the concave portion having a thin upper surface is used, but the same effect can be obtained as long as it is locally deformed. For example, the side surface may be recessed so as to be bundled in a plan view. In order to lock the domain wall, the length in the fine line direction of the region deformed in the magnetic fine wire 1, here the groove width of the recess 1 trp (the length in the thin line direction in the opening of the recess 1 trp) is equal to or greater than the thickness of the domain wall. It is preferable to make it less than twice. If the groove width of the recess 1trp is too wide, the error range of the magnetic wall locking position becomes large. Specifically, the length in the fine line direction of the recess 1trp is preferably about 100 nm or less in the range of about 10 to 500 nm, about 1/10 to 2 times the width of the magnetic thin line 1, and 1/2 or less of the bit length Lb. Is preferred. Further, in the magnetic wire 1, the deformed portion such as the concave portion 1 trp is 2-40% of the change amount with respect to the original thickness (region other than the concave portion 1 trp) in order to suitably lock the domain wall. It is preferable to make it.

  In the magnetic thin wire 1, a reproducing region 1r is set in the vicinity of the positive electrode 31, and a writing region 1w is set in the vicinity of the negative electrode 32. As shown in FIG. It is preferable to be provided on a straight line along the diameter. The write area 1w is a thin line direction set so as to change (magnetize) the magnetic wire 1 to a magnetization direction corresponding to one (1 bit) data recorded on the magnetic wire 1 by limiting the magnetic wire 1 to this area. It is an area delimited by. Therefore, at least in this region, the magnetic thin wire 1 is provided in the magnetic recording / reproducing apparatus 50 in order to magnetize the magnetic wire 1 in the desired magnetization direction upward or downward (to be written appropriately). A structure corresponding to the recording (writing) method of the data recording unit (magnetizing means) 5 is adopted. Here, as a magnetic field application method, which is a general recording method for a magnetic disk, the data recording unit 5 is a recording magnetic head (only the main magnetic pole portion is shown in FIG. 3). The portion including the write region 1w has a laminated structure in which a soft magnetic layer is provided on the lower side through a nonmagnetic layer (not shown). The length in the thin line direction of the writing area 1w may be equal to or longer than the bit length Lb, and is set to a length corresponding to the recording method, processing accuracy, and the like. Similarly, the data reproducing unit (magnetic detecting means) 6 is a reproducing magnetic head, and the portion including the writing area 1w of the magnetic wire 1 has a structure capable of detecting the magnetism of the magnetic wire 1 (illustrated). (Omitted).

  The magnetic fine wire 1 is preferably laminated with a protective film (not shown) on the upper surface in order to protect the magnetic fine wire 1 from damage during manufacture of the magnetic recording medium 10. The protective film is composed of a single layer of Ta, Ru, Cu, or two layers of Cu / Ta, Cu / Ru, etc., and in the case of a two-layer structure, all have Cu inside (lower layer). Further, the magnetic fine wire 1 may be formed on a base film made of a metal thin film in order to obtain adhesion with the substrate 2 (not shown). A nonmagnetic metal material such as Ta, Ru, Cu, Al, Au, Ag, or Cr can be applied to such a base film. Each of the protective film and the base film is preferably 1 to 10 nm in thickness. If the thickness is less than 1 nm, it is difficult to form a continuous film. On the other hand, if the thickness exceeds 10 nm, the effect is not further improved.

(substrate)
The substrate 2 is a base of the magnetic recording medium 10 for forming the magnetic wire 1 and is a broad substrate. As such a substrate 2, a known substrate material can be applied. Specifically, a Si (silicon) substrate having a thermal oxide film formed on its surface, SiO ₂ (silicon oxide, glass), MgO (magnesium oxide), Sapphire, GGG (gadolinium gallium garnet), SiC (silicon carbide), Ge (germanium) single crystal substrate, or the like can be applied. If the substrate 2 is a Si substrate and an oxide film having a sufficient thickness is not formed on the surface, an insulating film is formed on the surface and the magnetic wire 1 may be formed. That is, at least the surface (surface layer) of the substrate 2 may be insulative.

(Insulating layer)
The insulating layer 4 is disposed between the magnetic thin wires 1 and 1 in the magnetic recording medium 10, or between the electrodes 31 and 31 and between the electrodes 32 and 32, and further between the substrate 2 and the magnetic thin wire 1 or between the magnetic thin wires 1. It may be arranged above. The insulating layer 4 is made of a known insulating material such as SiO ₂ , Si ₃ N ₄ , Al ₂ O _3, etc., and the same material may not be applied to the entire magnetic recording medium 10.

(electrode)
The electrode 31 and the electrode 32 are terminals for supplying a current to the magnetic wire 1 in one direction as a pair of electrodes, and are connected to the lower surface of the end of the magnetic wire 1 in FIG. In the present embodiment, since the + of the scanning current source (current supply means) 7 of the magnetic recording / reproducing apparatus 50 is connected to the electrode 31 and the − is connected to the electrode 32, the positive electrode 31 and the negative electrode 32 are appropriately selected. That's it. The electrodes 31 and 32 are made of a general metal electrode material such as a metal such as Cu, Al, Ta, Cr, W, Ag, Au, or Pt, or an alloy thereof, and are formed by sputtering or the like, and photolithography or the like. Is formed into a stripe shape. The thicknesses, widths, and lengths in the thin line direction of the electrodes 31 and 32 are set based on the pitch (track pitch) of the magnetic thin lines 1 and 1, the material, the supplied voltage / current, and the like.

(Magnetic recording / reproducing device)
The magnetic recording / reproducing apparatus 50 of the magnetic recording medium device 20 according to the first embodiment of the present invention includes a data recording unit (magnetizing means) that magnetizes the write area 1w of the magnetic wire 1 in the magnetization direction corresponding to the data to be recorded. 5. A data reproducing unit (magnetic detecting means) 6 for detecting the magnetization direction in the reproducing region 1r of the magnetic wire 1; a scanning current source (power source for supplying a direct current pulse current connected to the electrodes 31 and 32 of the magnetic wire 1); Current supply means) 7 (see FIG. 3). Such a magnetic recording / reproducing apparatus 50 is disposed so as to face the region where the electrodes 31 and 32 of the magnetic recording medium 10 and the regions 1r and 1w of the magnetic wire 1 are provided as shown in FIG. 1). The data recording unit 5 and the data reproducing unit 6 can be the same as a magnetic head provided in a general magnetic disk recording / reproducing apparatus. The magnetic head moves in the radial direction of the magnetic recording medium 10 by a moving mechanism (not shown) built in the magnetic recording / reproducing apparatus 50 and faces the areas 1r and 1w of the selected magnetic thin wire 1. Further, the magnetic recording / reproducing apparatus 50 selects the terminals connected to the electrodes 31 and 32 of all the magnetic thin wires 1 of the magnetic recording medium 10 and connects the magnetic thin wire 1 to connect the scanning current source 7 or the data recording unit 5 or the data reproducing device. A control unit for moving the unit 6 (magnetic head) and a support base for fixing the magnetic recording medium 10 are provided (not shown). A known device can be applied to these elements of the magnetic recording / reproducing apparatus 50, but the magnetic field applied to the magnetic recording medium 10 (magnetic thin wire 1) from the coils 80, 80 is not blocked.

The scanning current source 7 is a power source that supplies a direct current (scanning current Isc) as a pulse current to the magnetic wire 1 in the thin wire direction. Here, + is connected to the electrode 31 and − is connected to the electrode 32. When the scanning current Isc is supplied to the magnetic thin wire 1 from the positive electrode 31 side to the negative electrode 32 side, the domain wall moves through the magnetic thin wire 1 in the opposite direction to the negative electrode of the magnetic thin wire 1. It moves along the thin line direction from the 32 side to the positive electrode 31 side, and the magnetic domain divided by the domain wall, that is, the data also moves (see FIG. 3). The direct current pulse current is preferably adjusted in the range of pulse width (peak period) t _H : 1 ps to 10 μs and stop time (base period) t _L : 10 ps to 10 μs. The pulse width t _H depends on the moving speed of the magnetic domain. The predetermined time is set to the time for moving, and the stop time t _L is set to be longer than the write time t _W by the data recording unit 5.

The scanning current Isc (peak current) in the DC pulse current is in the range of current density: 10 ⁸ to 10 ¹³ A / m ² , depending on the magnetic material of the magnetic wire 1 and the magnitude of the magnetic field applied from the coils 80 and 80. Thus, it is preferable to adjust so that the domain wall moves. For example, when the magnetic wire 1 is made of a Co / Ni multilayer film, the domain wall can move with a current density of about 4.5 × 10 ¹¹ A / m ² or more, but a magnetic field of ²⁰⁰ Oe is applied. The magnetic wall can be moved from a current density of about 3.0 × 10 ¹¹ A / m ² (see Non-Patent Document 3).

(Coil, coil power supply)
The coil 80 can generate a magnetic field of about several tens to several hundreds Oe with a sufficiently small current, and applies a magnetic field having a uniform size and direction to all the magnetic wires 1 of the magnetic recording medium 10. I just need it. An example of such a coil is a Helmholtz type coil. An upward magnetic field (synthetic magnetic field) H in FIG. 1 that is perpendicular to the magnetic recording medium 10 (film surface of the magnetic wire 1) is applied by the coils 80, 80 disposed above and below the magnetic recording medium 10. Each of the coils 80 is simplified in FIG. 1 and is represented by a solenoid coil in which the conducting wire 8 is wound four times. For example, the outer shape is housed in a cylindrical frame (not shown). The coil power supply 9 is a power supply that supplies a constant direct current Ia to the coils 80 and 80.

[Magnetic recording and playback method]
(Recording method)
Next, a method for writing (recording) data on the magnetic thin wire of the magnetic recording medium using the magnetic recording medium device according to the first embodiment of the present invention will be described.

  First, the coil power supply 9 is turned on, and a magnetic field having a predetermined magnitude is generated between the coils 80 and 80 and applied to all the magnetic wires 1 of the magnetic recording medium 10. The magnitude of the magnetic field is set to be smaller than the coercive force of the magnetic wire 1 so as not to change the magnetization direction of the magnetic wire 1.

  Next, based on a signal input from the outside, the magnetic recording device 50 selects the magnetic wire 1, the scanning current source 7 is connected to the electrodes 31 and 32 of the magnetic wire 1, and the writing of the magnetic wire 1 is further performed. The data recording unit 5 (recording magnetic head) is moved onto the recording area 1w (selection step). Then, the data recording unit 5 sets the writing area 1w to a magnetization direction based on one data input from the outside (magnetization process). Next, one pulse of pulse current is supplied from the scanning current source 7 to the magnetic wire 1. By supplying one pulse of this current Isc, the domain wall generated in the magnetic wire 1 moves the distance of the bit length Lb. In the magnetic thin wire 1, the magnetic domain delimited by the magnetic domain wall is moved equidistantly (shifted) with the movement of the magnetic domain wall (magnetic domain moving step). Then, during the stop period in the pulse current, the data recording unit 5 again sets the writing area 1w to the magnetization direction based on the next one data (magnetization process).

  Thereafter, the magnetic domain moving process and the magnetizing process are alternately repeated, and the data is sequentially recorded for the selected magnetic wire 1. Note that one time of the magnetic domain moving process is a peak period in the pulse current, and it is sufficient that the pulse current is continuously supplied from the scanning current source 7, and the magnetization process is performed in accordance with the timing of the stop period in the pulse current. When all the data to be stored in the selected magnetic wire 1 is recorded, the next magnetic wire 1 is selected again by the selection process, and the same process as the first magnetic wire 1 is repeated. When the recording of all the data is completed, the coil power supply 9 is turned off and the application of the magnetic field is stopped.

(Playback method)
The method of reading (reproducing) data recorded on the magnetic wire 1 of the magnetic recording medium 10 is the same as that of the recording method described above, except that the magnetization of the reproduction region 1r of the selected magnetic wire 1 is changed to a data reproducing unit. A magnetic detection step of detecting with 6 (reproducing magnetic head) may be performed.

  In the magnetic recording / reproducing method according to this embodiment, the coil power supply 9 is turned on and a magnetic field is applied to the magnetic recording medium 10 by the coils 80, 80 during recording or reproduction of all data on the magnetic recording medium 10. Except for this, the method is the same as that described in Patent Documents 2 to 4. The magnetic field may be applied to at least the selected magnetic wire 1 during the magnetic domain moving step (peak period in the pulse current). However, the coils 80 and 80 of the magnetic recording medium device according to the first embodiment are specifications that apply a magnetic field to the entire magnetic recording medium 10 and are coils in which the conducting wire 8 is wound several times. Since an AC component is generated as an inductor immediately after the supply of current is stopped, the magnetic field is not stable if ON and OFF are performed in a short period of time, such as a pulse current. Therefore, in this embodiment, it is preferable to keep the coils 80 and 80 energized and continue to apply a magnetic field.

  In the magnetic recording / reproducing method according to this embodiment, two or more magnetic wires 1 may be selected in the selection step, and a pulse current may be supplied to these magnetic wires 1 in parallel to simultaneously move the magnetic domains. As the number of magnetic thin wires 1 supplying pulse currents in parallel increases, the time required for recording or reproduction on all the magnetic thin wires 1 of the magnetic recording medium 10 is shortened. Since the time for supplying the current Ia to the coils 80 and 80 is also shortened, the total amount of current used can be reduced. At this time, the magnetic recording / reproducing apparatus 50 includes the data recording units 5 and the data reproducing units 6 corresponding to the number of the magnetic thin wires 1 that supply the pulse current in parallel. Data recording or reproduction may be executed simultaneously for the selected magnetic thin wires 1 or may be executed sequentially one by one during one stop period of the pulse current. Further, the set of magnetic thin wires 1 selected at the same time may be adjacent magnetic thin wires 1 or may be a set of magnetic thin wires 1 separated by one or more.

  According to the magnetic recording / reproducing method using the magnetic recording medium device 20 according to the first embodiment, the peak current (current Isc) of the pulse current supplied to the magnetic wire 1 by the magnetic field H applied from the coils 80 and 80 is obtained. Can be reduced. Note that the current Ia supplied to the coils 80, 80 can be made smaller than the reduction amount of the current Isc due to the magnetic field H, so that the power consumption of the entire magnetic recording medium device 20 can be reduced.

(Modification)
In the magnetic recording medium device 20, the type and shape of the coil 80 are not particularly limited as long as the coil 80 can apply a uniform magnetic field H to the entire magnetic recording medium 10 as described above. You may arrange | position only to one of upper direction or the downward direction. The coil 80 (80, 80) not only applies the magnetic field H for data shift movement in recording and reproduction, but also initializes the magnetic recording medium 10 (uniformly magnetizes all the magnetic wires 1). May be used to apply a strong magnetic field for aligning).

  The magnetic recording medium device 20 according to the first embodiment is not limited to the disk-shaped magnetic recording medium 10, but can apply a uniform magnetic field H to the entire magnetic recording medium (the region where the magnetic thin wire 1 is provided). For example, a rectangular plate-like magnetic recording medium 10A in which the linear magnetic thin wires 1 shown in FIG. 4 are juxtaposed can be recorded and reproduced. Further, when such a magnetic fine wire 1 is applied to recording and reproduction of a linear magnetic recording medium 10A, as shown in FIG. 4, the magnetic recording medium device 20A has a thin wire width direction of the magnetic fine wire 1, that is, magnetic recording. The coils 80, 80 may be arranged so as to apply the magnetic field H in the direction in which the magnetic thin wires 1 are arranged in the medium 10A. In the magnetic recording medium device 20A, the scanning current source 7 is connected to both ends of the linear magnetic wire 1, the writing region 1w is set at one end of the magnetic wire 1, and the reproduction region 1r is set at the other end. Therefore, magnetic recording / reproducing devices 50A are provided at two locations along both edges of the magnetic recording medium 10A.

  In the magnetic recording / reproducing method according to the first embodiment and its modification, the data recording method and reproducing method are not limited to the method using the magnetic head. In the data recording method, for example, spin injection magnetization reversal can be used. In this case, the magnetic recording medium 10 is provided with a spin-injection magnetization reversal element structure having the magnetic wire 1 as a magnetization free layer and a pair of electrodes connected to the upper and lower sides in the writing region 1w of the magnetic wire 1. The data recording unit 5 of the reproducing device 50 may be a power source that supplies current by being connected to the pair of electrodes (not shown). According to the spin injection magnetization reversal, writing can be performed at a speed higher than that of the magnetic system, and writing can be performed only in a region where the spin injection magnetization reversal element structure is formed.

In the data reproduction method, for example, the magnetism of the magnetic wire 1 can be detected by a magneto-optical method. In this case, the data reproducing unit 6 of the magnetic recording / reproducing apparatus 50, like a general magneto-optical disk reproducing apparatus, irradiates the reproducing area 1r of the magnetic wire 1 with a laser beam and the polarization of the reflected light. A polarizer or the like for detecting the orientation of the light is provided (not shown). In the magnetic recording medium 10 for reproducing data by such a method, the fine wire width of the magnetic fine wire 1 is set to 100 nm or more, the pitch and the bit length Lb are set to 200 nm or more, and the length is set according to the wavelength of the laser beam. Is preferred. Further, the magnetic recording medium 10 has a film thickness of 30 nm or more, or a non-film such as Al, Ag, etc. with an insulating film such as SiO ₂ sandwiched so that the magnetic wire 1 reflects light in the reproduction region 1r. A reflective film made of a magnetic metal is preferably provided.

  In the magnetic recording / reproducing method according to the first embodiment and its modification, the magnetic domain, that is, the direction of data shift movement, that is, the direction of the current supplied to the magnetic wire may be changed between data recording and reproduction. For example, in data recording, the electrode 31 is connected to-of the scanning current source 7 and the electrode 32 is connected to +. At this time, the data moving direction is opposite to the direction shown in FIGS. Therefore, when recording data in this way, in the magnetic thin wire 1, the writing area 1w is provided on the electrode 31 side together with the reproducing area 1r (not shown). Further, the data may be rearranged and recorded on the magnetic wire 1 in accordance with the order in which the data is reproduced.

(Spatial light modulator)
The magnetic recording / reproducing method according to the first embodiment and the modification thereof is a spatial light modulator in which linear magnetic thin wires are arranged in parallel as in the magnetic recording medium 10A shown in FIG. 4 (see Patent Document 5). ) Can be applied to the pixel. That is, the spatial light modulator according to the present embodiment includes a magnetic recording medium 10A serving as a pixel array, a magnetic recording / reproducing device 50A (see FIG. 4), and coils 80 and 80 (the magnetic field according to the first embodiment or a modification thereof). Recording medium device 20, 20A). However, the magnetic thin line 1 is a pixel in which only the writing area 1w is set and the reproduction area 1r is not provided, and the data storage area is continuous in the thin line direction. Further, the magnetic recording / reproducing apparatus 50 </ b> A is configured not to include the data reproducing unit (magnetic detection means) 6. In addition, the coil 80 (80, 80) has a sufficient inner diameter (inside the frame (not shown) that accommodates the conducting wire 8) so that the light entering and exiting the pixel array (magnetic thin wire 1) is not hindered. It is made larger or arranged only on the side opposite to the light incident / exit side, or arranged so as to apply a magnetic field in the direction of the fine wire width of the magnetic fine wire 1 as in the modification shown in FIG.

  As described above, according to the magnetic recording medium device according to the first embodiment of the present invention and the modifications thereof, the magnetic recording / reproducing method using the same, and the spatial light modulator, the existing magnetic recording medium and spatial light modulation are used. It is possible to reduce the current used for data recording and reproduction with respect to the detector, and to suppress the deterioration of the magnetic recording medium and the magnetic wire of the spatial light modulator.

[Second Embodiment]
The magnetic recording medium device according to the first embodiment includes a coil (magnetic field applying means) and a power source for the magnetic recording medium device and applies a magnetic field from the outside of the magnetic recording medium. In order to apply the magnetic field uniformly to the whole, the coil as the magnetic field applying means becomes larger, or the current supplied to the coil becomes larger. Therefore, by incorporating the magnetic field applying means in the magnetic recording medium, the current supplied to the magnetic field applying means can be suppressed in the vicinity of the magnetic thin wire. Hereinafter, a magnetic recording medium device according to a second embodiment of the present invention and a magnetic recording / reproducing method using the same will be described with reference to FIG. The same elements as those in the first embodiment (see FIGS. 1 to 4) are denoted by the same reference numerals, and description thereof is omitted.

(Magnetic recording medium)
As shown in FIG. 5, a magnetic recording medium 10B on which data is recorded and reproduced by the magnetic recording medium device according to the second embodiment has an insulating layer 4 sandwiched between concentric magnetic wires 1, 1,. Thus, a spiral coil (magnetic field applying means) 80A in plan view is provided. 5A, the structure of the magnetic recording medium 10B is simplified so that the conducting wire 8A of the coil 80A is represented in a linear shape, and the number of magnetic fine wires 1 and the number of windings of the conducting wire 8A are each represented by about 10. However, the plan view (the surface on the side where the magnetic wire 1 is formed) has the same structure as the magnetic recording medium 10 shown in FIG. That is, the magnetic recording medium 10B is provided with a large number of concentric circular magnetic wires 1 as shown in FIG.

  The coil 80A is shown in a simplified manner in FIG. 5A, but is a planar coil (spiral coil) formed by spirals in which the conductor 8A is tightly wound, and is incorporated in a magnetic head for recording, for example. The structure is the same as that of a thin film coil. The conductive wire 8A is formed of a general metal electrode material such as Cu, like the electrodes 31 and 32 (see FIGS. 2 and 3) connected to both ends of the magnetic fine wire 1, and the insulating layer 4 is provided between each circumference. (See FIG. 5B). Similarly to the magnetic wire 1, external terminals of the magnetic recording medium 10B are connected to both ends of the coil 80A (not shown). The conducting wire 8A is designed such that the thickness (width, film thickness) corresponds to the current Ia supplied to the coil 80A and the coil 80A has a sufficient number of turns. The coil 80A has a sufficiently narrow interval (between adjacent conducting wires 8A, 8A) (closely wound), and all the conducting wires 8A arranged in the radial direction along the radial direction. It is designed to generate a magnetic field H that circulates from the inside to the outside and further to the inside. Such a coil 80 </ b> A (conductive wire 8 </ b> A) is formed on the substrate 2 by a known method such as sputtering and etching, or printing with conductive ink in the same manner as the magnetic thin wire 1 and the electrodes 31 and 32.

  As shown in FIGS. 5 (a) and 5 (b), the magnetic field H generated by the coil 80A is on the magnetic recording medium 10B (substrate 2) along the upper and lower surfaces of the coil 80A (conductors 8A, 8A,...). Since the magnetic field is in the radial direction, a magnetic field is applied to each of the magnetic thin wires 1, 1,... Provided above the coil 80A in the thin wire width direction. Thus, since the magnetic field H is a magnetic field synthesized by all the conducting wires 8A, as shown in FIG. 5B, the conducting wire 8A in each circumference of the coil 80A is directly under (or immediately above) the magnetic wire 1. And need not be completely parallel to the magnetic wire 1. Therefore, the coil 80A is not concentric like the magnetic thin wires 1, 1,..., And is formed in a narrow pitch spiral composed of one conductor 8A regardless of the pitch of the magnetic thin wires 1, 1,. . With this configuration, the coil 80A can generate a sufficiently large magnetic field H with a small current Ia. Further, the coil 80A is arranged on the inner peripheral side and the outer peripheral side of the region where the magnetic fine wire 1 is formed in a plan view so that the uniform magnetic field H is applied to all the magnetic fine wires 1 of the magnetic recording medium 10B. It is preferable to form widely. Further, the distance (distance in the thickness direction) between the magnetic fine wire 1 and the conductive wire 8A may be completely insulated from each other by the interlayer insulating film (insulating layer 4), while from the coil 80A as the distance from the coil 80A increases. Since the magnetic field applied to the magnetic wire 1 becomes small, it is preferable that the interval is shorter so that the required magnetic field H can be obtained with a smaller current Ia.

  The magnetic wire 1 has the same configuration as the magnetic wire 1 (see FIGS. 2 and 3) of the magnetic recording medium 10 according to the first embodiment. That is, the magnetic thin wire 1 has electrodes 31 and 32 connected to both ends, and a reproduction area 1r and a writing area 1w are set (not shown in FIG. 5). As with the first embodiment, the reproducing region 1r of the magnetic wire 1 can be configured to correspond to a magnetic system using a magnetic head or a magneto-optical system. In particular, although depending on the detection accuracy of the magnetic head and the magnitude of the magnetic field H, the magneto-optical method is preferable to the magnetic method because the magnetic field H is applied from the coil 80A during reproduction.

  On the other hand, since the magnetic recording medium 10B according to the present embodiment is provided with the coil 80A below the magnetic wire 1, when a magnetic field application method is applied as a data recording method, a recording magnetic head (data recording unit 5) is provided. ) Are opposed to the upper side, the nonmagnetic layer and the soft magnetic layer are provided under the magnetic wire 1 to set the write region 1w. However, if a soft magnetic layer is provided under the magnetic wire 1, that is, between the coil 80 </ b> A, the soft magnetic layer serves as a magnetic shield, and the writing region 1 w of the magnetic wire 1 (the region where the soft magnetic layer is provided). ) May be insufficiently applied. Furthermore, since the soft magnetic layer is usually 100 nm or more in thickness and the nonmagnetic layer and the insulating layer 4 are also interposed, the distance (interlayer distance) between the magnetic wire 1 and the coil 80A (conductor 8A) becomes long. Therefore, when the magnetic field application method is applied to the magnetic recording medium 10B, it is necessary to increase the current Ia supplied to the coil 80A in order to secure the magnetic field H.

  In the magnetic recording medium 10B according to the present embodiment, spin injection magnetization reversal can be used as a data recording method. Specifically, in the write region 1w of the magnetic wire 1, an intermediate layer (barrier layer) and a magnetization fixed layer are stacked on the opposite surface (upper surface) of the coil 80A to form a spin injection magnetization reversal element structure. . When a pair of electrodes are connected to the upper and lower sides of the spin injection magnetization reversal element structure, an interlayer distance from the coil 80A is required to provide a lower electrode connected to the magnetization free layer (magnetic wire 1). In order to shorten the length, a spin-injection magnetization reversal element having a parallel dual pin structure (see JP 2012-78579 A) may be applied. For example, an intermediate layer (barrier layer), a magnetization fixed layer, and an electrode are stacked on each of the magnetic fixed lines 1 at two positions spaced apart in the thin line direction in the writing region 1w, and the magnetic fixed lines 1 The two electrodes connected to are used as a pair of electrodes (not shown).

  The magnetic recording medium 10B can be manufactured, for example, by the following method. First, a spiral coil 80A (conductor 8A) is formed of a metal material on the substrate 2, and an insulating film is formed thereon to fill the gap of the conductor 8A with the insulating layer 4, and then the upper surface (insulating). The layer 4) is ground and polished by chemical mechanical polishing (CMP) or the like to be flattened and smoothed. Are formed thereon, a spin-injection magnetization reversal element structure is formed in the writing region 1w of the magnetic wire 1, and an insulating layer 4 is formed to fill the space between the magnetic wires 1 and 1. To do. Finally, electrodes 31 and 32 connected to both ends of the magnetic wire 1, electrodes connected to the writing region 1 w (spin injection magnetization switching element structure), and terminals connected to both ends of the coil 80 </ b> A are formed. 10B is obtained. Alternatively, in the magnetic recording medium 10 </ b> B, after the magnetic thin wire 1 is formed on the substrate 2, the coil 80 </ b> A may be formed with the insulating layer 4 interposed therebetween. Alternatively, as another method, the magnetic recording medium 10B may be manufactured by forming the magnetic wire 1 and the coil 80A on different substrates and then bonding them (not shown).

(Magnetic recording medium device)
The magnetic recording medium device according to the second embodiment includes the magnetic recording / reproducing device 50 of the magnetic recording medium device 20 according to the first embodiment and a coil power source (magnetic field generating current source) 9 (see FIG. 1). 9 is connected to a terminal of a coil 80A built in the magnetic recording medium 10B and supplies a current Ia. As the magnetic recording / reproducing apparatus 50, the same apparatus as that of the first embodiment can be applied. Further, in the present embodiment, the magnetic recording medium 10B includes the magnetic field applying means (coil) 80A, so that the structure is the same. Regardless, the magnetic field to the magnetic recording medium 10B is not blocked.

[Magnetic recording and playback method]
Since the magnetic recording / reproducing method using the magnetic recording medium device according to the second embodiment of the present invention is the same as the magnetic recording / reproducing method according to the first embodiment, description thereof will be omitted. In this embodiment, as shown in FIGS. 5A and 5B, a magnetic field H is generated in the radial direction of the magnetic recording medium 10B, and all the magnetic wires 1 are arranged in the thin wire width direction (FIG. 5B). Is applied to the left). Further, similarly to the first embodiment, a pulse current may be supplied in parallel to two or more magnetic wires 1 to simultaneously move the magnetic domains.

(Modification)
Although the magnetic recording medium 10B according to the second embodiment includes one coil 80A in FIG. 5, the number of the coils 80A is not limited, and includes two or more coils 80A with the insulating layer 4 interposed therebetween, and is smaller. The magnetic field H can also be generated by the current Ia. Alternatively, in the magnetic recording medium 10B according to the second embodiment, a magnetic shield layer made of ferrite or the like may be laminated on the coil 80A on the opposite side (lower side in FIG. 5) of the magnetic wire 1 (not shown). With such a configuration, a structure in which the magnetic field H is applied to the magnetic wire 1 more efficiently can be achieved.

  In the magnetic recording medium according to the second embodiment, linear magnetic wires 1 may be arranged in parallel on a rectangular plate-like substrate 2 as in the magnetic recording medium 10A shown in FIG. 4, and a plurality of conductors 8A are magnetic wires. 1 are formed in a straight line parallel to 1 and arranged in parallel at a narrow pitch, and therefore the cross-sectional view shown in FIG. The magnetic recording medium having such a shape can also record and reproduce data by the magnetic recording and reproducing method according to the present embodiment. Here, in order to generate the magnetic field H, it is necessary to supply the current Ia to all of the linear conductors 8A, 8A,... In the same direction, but both ends of each conductor 8A are connected to a common terminal. When the current Ia is supplied in parallel, a current that is several times the number of the conductive wires 8A is supplied from the coil power supply 9. Therefore, for example, wiring parallel to the lower side of each conductive wire 8A (opposite side of the magnetic thin wire 1) may be provided, and the adjacent conductive wires 8A and 8A may be connected in series via this lower wiring ( Not shown). In other words, the conducting wires on the side facing the magnetic thin wire 1 obtained by flattening the solenoid coil in the radial direction are the conducting wires 8A, 8A,. Then, the magnetic recording medium and magnetic recording medium device in which such linear magnetic thin wires 1 are arranged side by side are used as a spatial light modulator as in the first embodiment, and the magnetic recording / reproducing method according to the second embodiment is used. A pixel can be written.

  In the second embodiment, the coil 80A (conductor 8A) is built in the magnetic recording medium 10B. However, the coil 80A (conductor 8A) may be provided in the magnetic recording medium device. Specifically, the magnetic recording medium device includes a coil 80A (not shown) on the surface layer of the support base on which the magnetic recording medium 10 is placed. At this time, in order to reduce the distance between the coil 80 </ b> A and the magnetic wire 1, a protective film (insulating film) on each of them is formed to be thin enough to have a thickness of about 10 to several tens of nm. It is preferable to place the thin wire 1 on the support table with the side provided with the thin wire 1 facing down. Further, when reproducing with the magnetic head (data reproducing unit 6), the substrate 2 is thinned at least in the region (see FIG. 2A) where the reproducing region 1r of the magnetic thin wire 1 is provided, and magnetic detection is possible. It is preferable to bring the magnetic head close to the magnetic wire 1 so that The reproducing magnetic head (data reproducing unit 6) is made to oppose the substrate 2 side of the magnetic recording medium 10, or the substrate 2 is applied with a material that transmits light and reproduced by a magneto-optical method. That's fine.

  As described above, according to the magnetic recording medium device and the magnetic recording / reproducing method using the magnetic recording medium device according to the second embodiment of the present invention and the modification thereof, and the spatial light modulator, the device is not increased in size. Since a sufficient magnetic field can be applied with a smaller current, the current used for data recording and reproduction can be further reduced, and the magnetic wires of the magnetic recording medium and the spatial light modulator can be deteriorated. Can be suppressed.

[Third Embodiment]
In the magnetic recording medium device and the magnetic recording medium according to the second embodiment, a coil in which a magnetic field applied to the magnetic wire of the magnetic recording medium is wound with a large number of conductive wires parallel (or substantially parallel) to the magnetic wire. However, the scanning current can be reduced even when a magnetic field generated by one conductor is applied. Hereinafter, a magnetic recording / reproducing method and a magnetic recording medium according to a third embodiment of the present invention will be described with reference to FIGS. The same elements as those in the first and second embodiments (see FIGS. 1 to 5) are denoted by the same reference numerals, and description thereof is omitted.

(Magnetic recording medium)
A magnetic recording medium 10C for recording and reproducing data by the magnetic recording / reproducing method according to the third embodiment is arranged side by side on the substrate 2 (only the surface is shown in the figure), as shown in FIG. 6 (a). Conductive wires 8B parallel to each of the magnetic thin wires 1 are provided immediately below the insulating layer 4 (blank portion in the figure). As will be described later, the magnetic recording medium 10C is limited to the conductor 8B directly below the magnetic thin wire 1 subject to magnetic domain movement (the direction of the second current from the right in FIG. 6A). An electric current is supplied to generate a magnetic field H. In FIG. 6A, for the sake of brevity, only four of the magnetic thin wires 1 and the conductor 8B immediately below are shown, but the magnetic recording medium 10C is the magnetic recording medium 10 of the first and second embodiments. , 10A, 10B, a large number of magnetic thin wires 1 are arranged side by side on the substrate 2, and a conductor 8B is provided immediately below each of the magnetic thin wires 1.

  Here, in order to generate a sufficiently large magnetic field H with the current flowing through one conductor 8B, this current is comparable to the scanning current Isc (peak current) supplied to the magnetic wire 1 or It is necessary to make it larger, and even if the reduction amount of the scanning current due to the effect of applying the magnetic field is subtracted, the total amount of current used increases on the contrary. Therefore, as shown in FIG. 6B, in the magnetic recording medium 10C, the magnetic thin wire 1 and the conductive wire 8B immediately below it are connected in series, and a current common to the magnetic thin wire 1 or a scanning current Isc is supplied to the conductive wire 8B. With this configuration, the magnetic field H to be applied to the magnetic wire 1 is generated without using a power source (coil power source) dedicated to the conducting wire (magnetic field applying means).

  Specifically, the conducting wire 8B is connected to the positive electrode 31B of the magnetic thin wire 1 at one end, and the opposite end (end portion 81) together with the negative electrode 32 of the magnetic thin wire 1 as a pair of terminals is used as a scanning current source (current). Supply means) 7. In other words, in the magnetic recording medium 10 </ b> C, the positive electrode 31 </ b> B is bent and extended downward so as to run parallel to the magnetic wire 1. For the sake of simplicity, the magnetic recording medium 10C represents only one of the magnetic wires 1 in a straight line in FIG. 6B, and the substrate 2 and the insulating layer 4 are omitted. In the magnetic recording medium 10C, linear magnetic thin wires 1 may be arranged on a rectangular plate-like substrate 2 like the magnetic recording medium 10A of the modification of the first embodiment, or in the first and second embodiments. Similarly to the magnetic recording media 10 and 10B, the concentric magnetic thin wires 1 may be formed on the disk-shaped substrate 2 (see FIGS. 4 and 2). Further, in the magnetic recording medium 10C, the conductive wire 8B, the insulating layer 4 (not shown), and the magnetic fine wire 1 may be provided in this order from the substrate 2 side. Conversely, the magnetic fine wire 1 is provided on the substrate 2 side. May be.

  The magnetic wire 1 has the same configuration as the magnetic wire 1 (see FIGS. 2 and 3) of the magnetic recording medium 10 and the like according to the first and second embodiments. However, when the length of the magnetic wire 1 is increased, a deviation due to the delay of the pulse current occurs between the vicinity of the electrode 32 in the magnetic wire 1 and the vicinity of the end portion 81 of the conducting wire 8B, and the opposing magnetic thin wire 1 and conducting wire 8B. The synchronization between them becomes incomplete. Therefore, the wire length of the magnetic wire 1 is designed so that this deviation is within a sufficiently small range with respect to the pulse width. In addition, since the conducting wire 8B is provided immediately below the magnetic wire 1, the structure in the writing region 1w is a spin injection magnetization reversal element having a parallel dual pin structure, as in the magnetic recording medium 10B according to the second embodiment. It is preferable to do.

  The electrodes 31B and 32 have the same configuration as the electrodes 31 and 32 in the first and second embodiments. In FIG. 6B, the electrodes 31B and 32 are connected to the upper surface of the magnetic wire 1, but the present invention is not limited to this. It is only necessary that one (here, the positive electrode 31B) can be connected to the conductor 8B.

  The conductive wire 8B is formed of a general metal electrode material such as Cu, similarly to the electrodes 31B and 32. Further, since the current Isc common to the magnetic wire 1 flows, the conductor 8B is formed to have a thickness (thickness and width) corresponding to the magnitude of the current Isc. Unlike the conductor 8A (coil 80A) in the second embodiment, the conductor 8B does not have to be thick with respect to the magnitude of the current because the flowing current is a pulse current. In the case of being long with 1, it is preferable to design the material and thickness so as to be low resistance in order to suppress the deviation due to the delay of the pulse current.

  As will be described later, in the magnetic recording medium 10C, a magnetic field H to be applied to the magnetic wire 1 immediately above is generated by passing a current through one conductor 8B. FIG. 7 shows the distance dependence of the magnetic field at a point separated from the magnetic wire in the thin wire width direction when a direct current of a certain size (0.5 mA, 1 mA, 2 mA) is supplied to the magnetic wire as a conducting wire. It is a graph which shows. As shown in FIG. 7, the magnetic field generated by the current flowing through the conducting wire attenuates in inverse proportion to the distance from the conducting wire. Although depending on the magnitude of the current Isc and the material of the magnetic wire 1, a sufficiently large magnetic field H is applied to the magnetic wire 1, so that the distance between the magnetic wire 1 and the conductor 8 </ b> B immediately below it is shown in FIG. 7. Is preferably narrower, specifically 40 nm or less. On the other hand, since each other is completely insulated by the interlayer insulating film (insulating layer 4) so that no leakage current or tunnel current flows, 3 nm or more It is preferable to make it.

  The magnetic recording medium 10C can be manufactured, for example, by the same procedure as the magnetic recording medium 10B according to the second embodiment. However, in the manufacture of the magnetic recording medium 10C, after forming the conductor 8B and the insulating layer 4 on the conductor 8B and between the conductors 8B, 8B, contact holes are formed in the insulating layer 4 on both ends of the conductor 8B, A metal electrode material is embedded, the positive electrode 31B is connected to one end of the conducting wire 8B, and the end portion 81 which is an external terminal is connected to the other end.

(Magnetic recording / reproducing device)
According to the magnetic recording / reproducing method according to the third embodiment, the magnetic field generating current source and the magnetic field applying means outside the magnetic recording medium (the coil power supply 9 and the coil 80 shown in FIGS. 1 and 4) are unnecessary, that is, existing The data can be recorded and reproduced using the magnetic recording / reproducing apparatus 50, 50A (see FIGS. 1 and 4). In the magnetic recording / reproducing apparatuses 50 and 50A, terminals for supplying a pulse current from the scanning current source 7 are arranged so as to be connected to the negative electrode 32 of the magnetic recording medium 10C and the end 81 of the conductor 8B. The

(Magnetic recording / reproducing method)
The magnetic recording / reproducing method according to the third embodiment of the present invention is the same as the magnetic recording / reproducing method according to the second embodiment except that the current Ia is not supplied. The data can be recorded and reproduced by the method described above. In the present embodiment, in the magnetic domain moving step (peak period in the pulse current), as shown in FIG. 6B, the peak current Isc is supplied to the magnetic thin wire 1 and at the same time, the conducting wire 8B running in parallel is also applied. The current Isc flows in the opposite direction to the magnetic wire 1. As shown in FIGS. 6A and 6B, the current Isc generates a magnetic field H in a direction rotating around the conducting wire 8B which is the current path of the current Isc. 6 (a) is applied to the left). Further, similarly to the first and second embodiments, a pulse current may be supplied in parallel to two or more magnetic thin wires 1 to simultaneously move the magnetic domains.

  According to the magnetic recording / reproducing method according to the third embodiment, a magnetic field is applied to the magnetic thin wire 1 in the thin wire width direction by connecting the conductive wire 8B in series with the magnetic thin wire 1 and running in parallel. The peak current (current Isc) of the supplied pulse current can be reduced. Further, since the magnetic field H is generated by the pulse current, the magnetic field H is not applied at the time of recording / reproduction which is a stop period in the pulse current, and therefore magnetic detection or the like is not affected by the magnetic field H. If the current Isc is reduced, the magnetic field H is also reduced. Therefore, the magnetic recording medium 10C has a material, thickness (width and thickness), and thickness of the magnetic wire 1 so that the current Isc is sufficiently reduced while obtaining a magnetic field H having an effective magnitude. It is preferable to design an interval between the conductor 8B and the like.

  The magnetic recording medium according to the third embodiment can be a pixel array of a spatial light modulator in which linear thin magnetic wires 1 are arranged side by side on a rectangular plate-like substrate 2, and a magnetic recording / reproducing method according to the present embodiment. Thus, it is possible to write in the pixels of the spatial light modulator. In the spatial light modulator according to the present embodiment, in order to increase the light extraction efficiency, the conductive wire 8B has at least the uppermost layer (the side facing the magnetic thin wire 1) having high reflectivity such as Al and Ag. Preferably it comprises a material (not shown).

(Modification)
The magnetic recording medium that records and reproduces data by the magnetic recording / reproducing method according to the third embodiment includes one conducting wire for supplying a current for generating a magnetic field for each magnetic thin wire. By generating a magnetic field by passing an electric current, it is possible to generate a magnetic field that is larger than the magnitude of the current than a single conductor. Hereinafter, a modified example of the magnetic recording medium that records and reproduces data by the magnetic recording and reproducing method according to the third embodiment (a magnetic recording medium according to a modified example of the third embodiment) will be described with reference to FIG. . The same elements as those in the first, second, and third embodiments (see FIGS. 1 to 6) are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 8 (a), the magnetic recording medium 10D according to a first modification of the third embodiment, just below the magnetic wire 1, spaced parallel to lead 8B ₁ and conductor 8B ₂ to the magnetic nanowire 1 The magnetic thin wire 1, the conducting wire 8B ₁ and the conducting wire 8B ₂ are connected in series in this order, and both ends are connected to the scanning current source (current supply means) 7 (see FIG. 6B) of the magnetic recording / reproducing apparatus. The In FIG. 8A, the magnetic recording medium 10D has a simplified structure, and represents only _one magnetic wire 1 and electrodes 31 and 32B connected to both ends of the magnetic wire 1 and conducting wires 8B ₁ and 8B _2. Furthermore, although the conducting wires 8B ₁ and 8B ₂ are represented in a linear shape, a large number of magnetic thin wires 1 are formed concentrically on a disk-shaped substrate 2 as in the magnetic recording medium 10 of the first embodiment shown in FIG. Further, each of the magnetic thin wires 1 is provided with conductive wires 8B ₁ and 8B ₂ , and an insulating layer 4 is further provided between them.

In the magnetic recording medium 10D according to this modification, it can be said that wire 8B ₁ and conductor 8B ₂ two (2 layers) current flows in the same direction, and thus constitute two laps wound solenoid coil. In the magnetic recording medium 10D, the conductors 8B ₁ and 8B ₂ are connected so that the current Isc supplied to the magnetic wire 1 flows in the direction opposite to that of the magnetic wire 1. Therefore, it can be said that the magnetic recording medium 10D is obtained by extending the conductor 8B of the magnetic recording medium 10C (see FIG. 6B) according to the third embodiment to a length twice as long.

The magnetic wire 1 has the same configuration as that of the magnetic wire 1 (see FIGS. 2 and 3) of the magnetic recording medium 10 according to the first embodiment, and a positive electrode 31 and a negative electrode 32B are connected to both ends. However, in the magnetic recording medium 10D according to this modification, the magnetic wire 1 is formed in an annular shape (for example, a C shape) that is partially missing in plan view so that both ends are close to each other. The positive electrode 31 is connected to the scanning current source 7, and the negative electrode 32B is connected to the scanning current source 7 via the conducting wires 8B ₁ and 8B ₂ .

The conducting wire 8B ₁ and the conducting wire 8B ₂ have the same configuration as that of the conducting wire 8B of the magnetic recording medium 10C according to the third embodiment, and a current Isc common to the magnetic thin wire 1 flows. And width). The conducting wires 8B ₁ and 8B ₂ are formed in a C shape lacking a part of the same ring as the magnetic wire 1 so as to run parallel to the magnetic wire 1 and currents flow in the same direction as each other. One end (termination) of the conducting wire 8B ₁ and the other end (starting end) of the conducting wire 8B ₂ are connected between the layers so as to flow. The conducting wire 8B ₁ is connected to the magnetic thin wire 1 through the negative electrode 32B, and is formed so as to substantially overlap the magnetic thin wire 1 in plan view, like the conducting wire 8B of the magnetic recording medium 10C. On the other hand, conductor 8B _2, as current flows in the same direction as the wire 8B ₁ connected to conductor 8B _1, displaced missing part of the ring in a plan view and conductor 8B _1, i.e. offset from the magnetic wire 1 Formed.

In the magnetic recording medium 10D, the distances between the magnetic thin wire 1, the conductive wires 8B ₁ , and the conductive wires 8B ₂ are 40 nm or less, 3 nm or more, as in the magnetic recording medium 10C according to the third embodiment, between the magnetic thin wires 1 and 8B. It is preferable to make it. In particular, by narrowing the space between the conductive wires 8B ₁ and 8B ₂ (interlayer), the conductive wires 8B ₁ and 8B ₂ become one coil, and a magnetic field H is generated as a whole and applied to the magnetic wire 1.

In FIG. 8A, the magnetic recording medium 10D is connected so that the currents Isc flow in the direction opposite to the magnetic wires 1 in the conductors 8B ₁ and 8B _2, but are connected in the same direction. (Not shown). Further, the magnetic recording medium 10D is not limited to the two-turn coils of the conductive wires 8B ₁ and 8B ₂ , but can increase the number of conductive wires (the number of turns of the coil) to generate a larger magnetic field H. However, since the current flowing in the conducting wire is a pulse current that is common to the magnetic thin wire 1, as described in the first embodiment, an AC component is generated immediately after the current supply is stopped, so that the magnetic field is not unstable. It is preferable to design the number of turns.

The magnetic recording / reproducing method of the magnetic recording medium 10D according to this modification is based on the magnetic recording / reproducing method according to the third embodiment. In this modification, in the magnetic domain moving process (peak period in the pulse current), as shown in FIG. 8A, the current Isc flows clockwise through the conductors 8B ₁ and 8B ₂ . As a result, a magnetic field H is generated around the bundle of _two conducting wires 8B ₁ and 8B ₂ through which the current Isc flows in parallel, and the magnetic wire 1 is formed in the radial direction of the magnetic recording medium 10D (from the outer periphery in FIG. 8A). Applied toward the center), that is, in the direction of the fine line width.

According to the magnetic recording / reproducing method of a magnetic recording medium according to the first modification of the third embodiment, the magnetic recording wire 10D is supplied to the magnetic wire 1 by the magnetic field H in the radial direction of the magnetic recording medium 10D, that is, the thin wire width direction of the magnetic wire 1. The peak current (scanning current Isc) of the pulse current can be reduced. In particular, in the present modification, since the magnetic field H is generated by the coil formed by the _two conductors 8B ₁ and 8B ₂ , a sufficiently large magnetic field H can be obtained without increasing the scanning current Isc. Further, in the magnetic recording / reproducing method of the magnetic recording medium according to the present modification, a pulse current may be supplied in parallel to two or more magnetic wires 1 and the magnetic domains may be moved simultaneously as in the third embodiment.

The magnetic field applied to the magnetic wire is not limited to one side of the magnetic wire, but can be applied from both sides. As shown in FIG. 8B, the magnetic recording medium 10E according to the second modification of the third embodiment includes a conductor 8B ₃ in parallel with the magnetic wire 1 and a conductor 8B directly above and below the magnetic wire 1, respectively. 8B ₁ is provided separately, and these conducting wires 8B ₃ and 8B ₁ are connected to both ends (electrodes 31B and 32B) of the magnetic wire 1. That is, the magnetic recording medium. 10E, conductor 8B _3, the magnetic wire 1 is connected in series in the order of conductor 8B _1, scanning current source across the magnetic recording and reproducing apparatus (current supplying means) 7 (FIG. 6 (b) see) Connected to. Similar to the magnetic recording medium 10D shown in FIG. 8A, the magnetic recording medium 10E has a simplified structure in FIG. 8B and is connected to one of the magnetic wires 1 and both ends of the magnetic wire 1. Only the electrodes 31B and 32B, and the conductive wires 8B ₃ and 8B ₁ are represented, and the conductive wires 8B ₁ and 8B ₂ are represented in a linear shape. However, like the magnetic recording medium 10 of the first embodiment shown in FIG. A large number of magnetic thin wires 1 are formed concentrically on the substrate 2, and each of the magnetic thin wires ₁ is provided with conductive wires 8 B ₃ and 8 B ₁ , and an insulating layer 4 is provided between them.

In the magnetic recording medium 10E, a conducting wire 8B ₁ provided below the magnetic wire 1 is connected to a conducting wire 8B ₃ provided on the magnetic wire 1 so that a current flows in the opposite direction similarly to the magnetic recording medium 10D. Are connected so that current flows in the same direction as the magnetic wire 1.

Magnetic wire 1 has the same configuration as the magnetic recording medium the magnetic wire 1 10D and the like according to a first modification of the third embodiment, the electrode 31B at both ends, but 32B is connected, connected to the conductor 8B ₃ Both the reproduction area 1r and the writing area 1w are set on one end side. This is because, as shown in FIG. 8B, in the vicinity of the other end of the magnetic wire 1, the conductors 8B ₃ and 8B ₁ are provided directly above and below, so that the data recording unit of the magnetic recording / reproducing apparatus 50 is provided. This is because it is difficult to make 5 and the data reproducing unit 6 face each other close to each other. However, depending on the recording / reproducing method, if the data recording unit 5 or the data reproducing unit 6 facing the magnetic thin wire 1 through the conductors 8B ₃ and 8B ₁ can detect the magnetization or magnetism of the magnetic thin wire 1 This is not the case.

The conducting wire 8B ₁ and the conducting wire 8B ₃ have the same configuration as the conducting wires 8B ₁ and 8B _{2 of the} magnetic recording medium 10D according to the first modification of the third embodiment, and a current Isc common to the magnetic thin wire 1 flows.

In the magnetic recording medium 10E, the intervals between the conducting wire 8B ₃ , the magnetic thin wire 1 and the conducting wire 8B ₁ are 40 nm or less, as in the magnetic recording media 10C and 10D according to the third embodiment and the first modification thereof. It is preferable to set it to 3 nm or more. With such a structure, as will be described later, both the magnetic fields H _A and H _B generated by the current Isc flowing through each of the conductive wires 8B ₃ and 8B ₁ are applied to the magnetic wire 1.

The magnetic recording / reproducing method of the magnetic recording medium 10E according to this modification is based on the magnetic recording / reproducing method according to the third embodiment, similarly to the magnetic recording medium 10D. However, as described above, in the magnetic recording medium 10E, since both the reproducing area 1r and the writing area 1w are set on one end side of the magnetic thin wire 1, pulse current is supplied in the opposite direction for recording and reproducing data. Then, the moving direction of the data (magnetic domain) is reversed. The direction of the current Isc shown in FIG. 8B is that during data reproduction. In this modification, the magnetic domain movement step (peak time of the pulse current), as shown in FIG. 8 (b), current Isc is clockwise on lead 8B _1, it flows counterclockwise on lead 8B _3. Thereby, magnetic fields H _A and H _B opposite to each other are generated around each of the conductive wires 8B ₃ and 8B ₁ , and the radial direction of the magnetic recording medium 10E (see FIG. 8B) ) Are applied in the same direction in the thin line width direction from the outer periphery to the center), and are combined into a larger magnetic field H _syn .

According to the magnetic recording / reproducing method of the magnetic recording medium according to the second modification of the third embodiment, the magnetic recording wire 10E is supplied to the magnetic wire 1 by the magnetic field H _{syn in} the radial direction of the magnetic recording medium 10E, that is, the thin wire width direction of the magnetic wire 1. The peak current (scanning current Isc) of the pulse current can be reduced. In particular, the present modification, the two conductors 8B _3, 8B ₁ of the magnetic field H _A that is applied from the upper and lower magnetic wire 1 in the same direction in the magnetic wire 1, since the H _B are combined, the scan current Isc Even if it is not increased, a sufficiently large magnetic field H can be obtained. Further, in the magnetic recording / reproducing method of the magnetic recording medium according to the present modification, a pulse current may be supplied in parallel to two or more magnetic wires 1 and the magnetic domains may be moved simultaneously as in the third embodiment.

  As described above, according to the magnetic recording / reproducing method and the spatial light modulator according to the third embodiment of the present invention and the modifications thereof, data recording and reproducing can be performed using the existing recording / reproducing apparatus for magnetic recording media. The current used at the time can be reduced, and the deterioration of the magnetic wire of the magnetic recording medium or the spatial light modulator can be suppressed.

[Fourth Embodiment]
In the magnetic recording / reproducing method and the magnetic recording medium according to the third embodiment, the configuration is such that a conducting wire runs in parallel for each magnetic wire and a magnetic field is applied from this conducting wire to one magnetic wire. It is also possible to apply a magnetic field from the conducting wire to the two magnetic wires. Hereinafter, a magnetic recording / reproducing method and a magnetic recording medium according to a fourth embodiment of the present invention will be described with reference to FIG. The same elements as those in the first, second, and third embodiments and the modifications thereof (see FIGS. 1 to 8) are denoted by the same reference numerals, and description thereof is omitted.

(Magnetic recording medium)
As shown in FIG. 9A, a magnetic recording medium 10F for recording and reproducing data by the magnetic recording / reproducing method according to the fourth embodiment is arranged side by side on the substrate 2 (only the surface is shown in the figure). For every two adjacent magnetic wires 1, one parallel conductor 8 </ b> C is provided below the two magnetic wires 1, 1, and an insulating layer 4 (blank portion in the figure) is provided between them. It is done. Here, it arrange | positions so that height may substantially correspond with the lower surface of the magnetic fine wire 1, and the upper surface of the conducting wire 8C. In FIG. 9 (a) and FIG. 9 (b) to be described later, for the sake of simplicity, only four magnetic thin wires 1 and two conductor wires 8C are shown. As in the case of the magnetic recording medium 10 of the first, second, and third embodiments, a large number of magnetic wires 1 are arranged on the substrate 2, and a conductor 8 </ b> C is provided for every two adjacent magnetic wires 1. is there.

  The magnetic wire 1 has the same configuration as the magnetic wire 1 (see FIGS. 2 and 3) of the magnetic recording media 10 and 10B according to the first and second embodiments, and is linear or circular in a plan view. You may form in any of the C shape which lacked the part. Further, electrodes 31 and 32 are connected to both ends of magnetic thin wire 1, and reproduction region 1r and writing region 1w are set (not shown in FIG. 9). In the magnetic recording medium 10F according to the present embodiment, since no conducting wire is disposed immediately above and below the magnetic thin wire 1, the structure of each region 1r, 1w is similar to the magnetic recording medium 10 according to the first embodiment. There are few regulations.

  The conducting wire 8C is formed of a general metal electrode material such as Cu, similar to the conducting wire 8A of the magnetic recording medium 10B according to the second embodiment, and has a shape that matches the planar view shape of the magnetic fine wires 1 that run in parallel. Further, it is formed to have a thickness (thickness and width) corresponding to the current Ia supplied to generate the magnetic field H. In particular, in the magnetic recording medium 10F according to the present embodiment, the conductor 8C is formed thick to suppress the width so that the distance between the magnetic thin wires 1 and 1 running in parallel on both sides of the conductor 8C does not become too large. preferable. Similarly to the magnetic wire 1, external terminals of the magnetic recording medium 10 </ b> F are connected to both ends of the conducting wire 8 </ b> C (not shown).

  In the magnetic recording medium 10F, the distance between the conductive wire 8C and each of the fine magnetic wires 1 and 1 on both sides thereof is 40 nm or less and 3 nm or more, as in the magnetic recording medium 10C according to the third embodiment and its modification. Preferably, the two magnetic thin wires 1 and 1 on both sides are arranged at an equal distance from the conductor 8C. With such a structure, as will be described later, a magnetic field H generated by a current Ia flowing through one conductor 8C is applied to the two magnetic wires 1 and 1 on both sides. Note that, as described above, in FIG. 9A, the lower surface of the magnetic wire 1 and the upper surface of the conductor 8C are arranged so that the heights coincide (interlayer distance = 0). The positional relationship in the height (thickness) direction of 8C is not limited to this. For example, a film of the insulating layer 4 (not shown) may be provided on the conductive wires 8C arranged in parallel, and the magnetic fine wires 1 may be arranged in parallel thereon (interlayer distance> 0). On the contrary, the magnetic fine wire 1 and the conducting wire 8C may overlap in the thickness direction (interlayer distance <0), and the magnetic fine wire 1 and the conducting wire 8C are provided so that the thickness direction centers thereof coincide. Is ideal, that is, the magnetic fine wire 1 and the conductive wire 8C are arranged in parallel in the same layer with the insulating layer 4 interposed therebetween. The distance between the magnetic wire 1 and the conductive wire 8C is a distance in two dimensions (cross section shown in FIG. 9A) in the thickness direction and the width direction. If the arrangement shown in FIG. This coincides with the distance in the width direction (left-right direction in FIG. 9A).

  The magnetic recording medium 10F can be manufactured, for example, in the same procedure as the magnetic recording medium 10B according to the second embodiment.

(Magnetic recording medium device)
Similar to the magnetic recording medium device according to the second embodiment, the magnetic recording medium device according to the fourth embodiment includes a magnetic recording / reproducing device 50 and a coil power supply (magnetic field generating current source) 9 (see FIG. 1). However, the magnetic recording / reproducing apparatus 50 is configured to simultaneously select two adjacent magnetic thin wires 1 and 1 of the magnetic recording medium 10F, and the scanning current source (current supply means) 7 supplies the pulse current in parallel. . The data recording unit 5 and the data reproducing unit 6 are configured to be capable of recording and reproducing by facing both of the two magnetic thin wires 1 and 1. The coil power supply 9 is controlled so that the conductor 8C between the two magnetic wires 1 and 1 selected by the magnetic recording / reproducing apparatus 50 is selected and connected to the external terminal.

[Magnetic recording and playback method]
In the magnetic recording / reproducing method using the magnetic recording medium device according to the fourth embodiment of the present invention, two adjacent magnetic wires of the magnetic recording medium are selected in the selection step, and the set of selected magnetic wires is used. In addition, the magnetic recording / reproducing method according to the first and second embodiments is the same as that of the first and second embodiments except that the conducting wire for supplying a current is switched.

  Specifically, first, the magnetic recording device 50 selects a pair of two adjacent magnetic thin wires 1 and 1 of the magnetic recording medium 10F, and then both ends of the conducting wire 8C between the selected magnetic thin wires 1 and 1. The coil power source 9 is connected to the external terminal of the terminal and is turned on to supply the current Ia to the conductor 8C. Then, the scanning current source 7 is connected to the respective electrodes 31 and 32 of the selected magnetic thin wires 1 and 1, and the data recording unit 5 (recording is performed on the writing areas 1w and 1w of these magnetic thin wires 1 and 1, respectively. (Magnetic head) is moved (in the case of the recording method). The following is the same as the magnetic recording / reproducing method according to the first and second embodiments except that data is recorded in parallel on the two magnetic wires 1 and 1, and reproduction is also performed in parallel. Do.

  According to the magnetic recording and reproducing method according to the present embodiment, as shown in FIG. 9A, a set of selected magnetic thin wires 1 and 1 of the magnetic recording medium 10F (from left to right in FIG. 9A, 1 and 2). The magnetic field H in a direction rotating around the lead 8C is generated by the current Ia flowing through the lead 8C arranged between the first and the second. This magnetic field H is applied in a substantially vertical direction to both sides of the conducting wire 8C, that is, to each of the selected magnetic fine wires 1 and 1. Specifically, in FIG. 9A, the magnetic field H is applied substantially downward to the left magnetic wire 1 of the conducting wire 8C and substantially upward to the right magnetic wire 1. Since the conductor 8C and each of the magnetic wires 1 and 1 on both sides thereof are equidistant, a magnetic field H of the same magnitude is applied to these magnetic wires 1 and 1, and the effect of reducing the scanning current Isc is equivalent. In the magnetic domain moving step (peak period in the pulse current), the data is shifted together with a small scanning current Isc. In FIG. 9A, the currents Isc and Ia are supplied in the opposite directions by the magnetic thin wires 1 and 1 and the conductor 8C, but they may be supplied in the same direction. Further, the current Ia supplied to the conducting wire 8C is not limited to a continuous current, but may be a pulse current synchronized with the scanning current Isc (pulse current).

  In the present embodiment, a relatively large current Ia is required in order to generate the magnetic field H with the current Ia supplied to one conductor 8C. Therefore, by recording and reproducing data in parallel on the two adjacent magnetic wires 1 and 1, an increase in the total amount of current used as the entire magnetic recording medium device is suppressed. It is also possible to record and reproduce data for only one magnetic wire 1 on one side of the conducting wire 8C. Alternatively, two or more pairs of adjacent magnetic wires 1 and 1 may be selected in the selection step, that is, a pulse current may be supplied in parallel to four or more magnetic wires 1 to simultaneously move the magnetic domains. At this time, the current Ia does not have to be supplied to the respective conductors 8C in the same direction. For example, the conductors 8C and 8C adjacent to each other may be supplied in the opposite direction. Therefore, for example, in the magnetic recording medium 10 </ b> F, the conductor 8 </ b> C may be formed of a single wire that is folded at the end and meanders (not shown). In the magnetic recording medium 10F having such a configuration, the magnetic field H is simultaneously applied to all the magnetic wires 1 including those not selected.

(Modification)
The magnetic recording medium 10F according to the fourth embodiment generates a magnetic field H by a current flowing through one conductive wire 8C, but generates a magnetic field by causing a current to flow through two or more conductive wires. Thus, a sufficiently large magnetic field H can be generated while suppressing the magnitude of the current. Hereinafter, a magnetic recording / reproducing method and a magnetic recording medium according to a modification of the fourth embodiment will be described with reference to FIGS. The same elements as those in the first to fourth embodiments (see FIGS. 1 to 8 and FIG. 9A) are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 9B, a magnetic recording medium 10G according to the first modification of the fourth embodiment is provided with two upper and lower conductive wires 8C and 8C between the magnetic fine wires 1 and 1, and this conductive wire. The current Ia is supplied to the set of 8C and 8C in the same direction. The positional relationship and distance between the magnetic wire 1 and the conductor 8C are the same as those of the magnetic recording medium 10F (see FIG. 9A). Furthermore, in the magnetic recording medium 10G, it is preferable that the magnetic fine wires 1 and 1 and the upper and lower conductive wires 8C and 8C are arranged at equal distances. With this configuration, the magnetic fields H and H applied from above and below are combined with the magnetic field H _syn in the vertical direction in each of the magnetic wires 1 and 1.

The magnetic recording medium 10G according to the present modification can be formed by, for example, a solenoid coil that wraps around the conductor 8C at the end between two pairs of magnetic thin wires 1 and 1, for example. Specifically, in FIG. 9 (b), the lower conductor 8C between the left pair of magnetic wires 1, 1 is folded at the end and connected to the lower conductor 8C between the right pair of magnetic wires 1, 1. The conductor 8C is folded back at the opposite end, and further connected to the upper conductor 8C on the left side through the interlayer, and connected to the upper conductor 8C on the right side in the same manner as the lower conductor 8C. That is, the conducting wires 8C, 8C, 8C, 8C shown in FIG. 9B are formed by one continuous line. Alternatively, as in the magnetic recording medium 10D according to the first modification of the third embodiment (see FIG. 8A), the magnetic wire 1 has a ring shape (for example, a C shape) that is partially missing in plan view. Once formed, the conducting wires 8C and 8C can be formed by two round solenoid coils connected between the layers so that current flows in the same direction as the conducting wires 8B ₁ and 8B ₂ . Such a magnetic recording medium 10G can be manufactured, for example, in the same procedure as the magnetic recording medium 10B according to the second embodiment. In FIG. 9B, two conductors 8C and 8C are provided between a pair of magnetic wires 1 and 1. However, the current Ia is further reduced by providing three (three layers) conductors. It can also be done (not shown).

In the magnetic recording medium device and the magnetic recording / reproducing method using the same according to the first modification of the fourth embodiment of the present invention, the current Ia is supplied to the upper and lower conductive wires 8C and 8C simultaneously and in the same direction. Other than the above, the fourth embodiment is the same as the fourth embodiment. In the present modification, the combined magnetic field H _syn is generated by the current Ia supplied to the two upper and lower conductive wires 8C, 8C, so that the current Ia can be reduced.

As shown in FIG. 9C, the magnetic recording medium 10H according to the second modification of the fourth embodiment is provided with conductive wires 8D (8D _A , 8D _B ) between all the magnetic wires 1 and 1, The current Ia is supplied to these conducting wires 8D while changing the direction one by one. In other words, in the magnetic recording medium. 10H, wire 8D _A running parallel to both sides of each of the magnetic wire 1, the current Ia is supplied in opposite directions to 8D _B. For this purpose, the magnetic recording medium 10H is provided with one more conductive wire 8D than the magnetic fine wire 1, and in FIG. 9C, the two magnetic fine wires 1, 1 and the three conductive wires 8D _A , 8D _B , 8D _A is shown. With this configuration, the magnetic fields H _A and H _B applied from both sides of the magnetic wire 1 are combined with the magnetic field H _syn in the vertical direction in the magnetic wire 1.

The conducting wire 8D _A and the conducting wire 8D _B have the same structure and are given different symbols to distinguish the difference in the direction in which the current Ia flows, and are collectively referred to as a conducting wire 8D as appropriate. Wire 8D has the same structure as the conductors 8C magnetic recording medium 10F (see FIG. 9 (a)), conducting wire 8D _A between both sides magnetic wire 1 in a magnetic recording medium 10H, positional relationship and the distance between the 8D _B These are the same as the positional relationship between the magnetic wire 1 and the conductor 8C in the magnetic recording medium 10F. Further, in the magnetic recording medium 10H, the conductive wires 8D (8D _A , 8D _B ) can be formed by one that folds at the end and meanders as described in the magnetic recording medium 10F according to the fourth embodiment. Such a magnetic recording medium 10H can be manufactured, for example, in the same procedure as the magnetic recording medium 10B according to the second embodiment.

The magnetic recording medium device according to the second modification of the fourth embodiment of the present invention and the magnetic recording / reproducing method using the same are the same as those of the fourth embodiment, but any magnetic recording / reproducing method can be selected in the selecting step. of can select one or more magnetic thin wire, also supplies a current Ia in opposite directions on both sides of the conductive wire 8D _a of the selected magnetic wire 1, the 8D _B. Further, when the single conductor 8D is formed in the magnetic recording medium 10H, the combined magnetic field _Hsyn is applied to all the magnetic wires 1, so that it is not necessary to switch the conductor 8D that supplies the current Ia. Hereinafter, the magnetic recording / reproducing method according to this modification will be described in detail with reference to FIG.

As shown in FIG. 9C, in the magnetic recording medium 10H, two or more adjacent conductors 8D _A , 8D _B , and 8D _A are alternately switched in direction and the current is changed. If Ia is supplied, each of the conductive wires 8D _a, 8D _B, the direction of rotation of the 8D _a in the axial magnetic field H _a, H _B, is H _a generates. Specifically, lead 8D _A ends, 8D generates the magnetic field H _A around each of _A, wire 8D _A, 8D _A magnetic field around the central conductor 8D _B of the current Ia is supplied in a direction opposite to the H _B produces.

In this case, (in FIG. 9 (c), the same applies hereinafter) left in the magnetic wire 1, downward magnetic field H _A from conductor 8D _A to the left, downward magnetic field H _B from the right side of the wire 8D _B, respectively Applied. Therefore, a large combined magnetic field H _{syn obtained} by combining the magnetic fields H _A and H _B is applied downward to the magnetic wire 1. Similarly, a magnetic field H _B is applied upward to the right magnetic thin wire 1 from the left conductor 8D _B and a magnetic field H _A is applied upward from the right conductor 8D _A to synthesize the magnetic fields H _B and _HA. The synthesized magnetic field H _syn applied is applied upward.

In the present modification, the combined magnetic field H _syn is generated by the current Ia supplied to the two conducting wires 8D _A and 8D _B on both sides of the magnetic wire 1, so that the current Ia can be reduced.

  The magnetic recording medium according to the fourth embodiment and its modification can be a pixel array of a spatial light modulator in which straight magnetic thin wires 1 are arranged in parallel on a rectangular plate-like substrate 2, and the magnetic recording medium according to the present embodiment. The pixel of the spatial light modulator can be written by the magnetic recording / reproducing method.

  As described above, according to the magnetic recording medium device, the magnetic recording / reproducing method using the same, and the spatial light modulator according to the fourth embodiment of the present invention and its modification, the device is similar to the second embodiment. Does not increase in size, and the current flowing through the magnetic fine wire of the magnetic recording medium during data recording and reproduction can be reduced, so that deterioration of the magnetic fine wire can be suppressed.

[Fifth Embodiment]
In the magnetic recording / reproducing method and magnetic recording medium according to the third embodiment, a magnetic wire of the magnetic recording medium is made to run parallel to a magnetic wire that carries a current common to the magnetic thin wire, and a magnetic field is applied from the conductive wire. However, the magnetic thin wire itself also generates a magnetic field by a current flowing through it as a conducting wire. That is, it can be said that the magnetic thin wire can be used as the magnetic field applying means. A magnetic recording / reproducing method and a magnetic recording medium according to the fifth embodiment of the present invention will be described below with reference to FIG. The same elements as those in the first to fourth embodiments (see FIGS. 1 to 9) are denoted by the same reference numerals and description thereof is omitted.

(Magnetic recording medium)
A magnetic recording medium 10I for recording and reproducing data by the magnetic recording / reproducing method according to the fifth embodiment has two or more even number of magnetic thin wires 1, 1,... Arranged in parallel on a substrate 2 (not shown). Prepare. The magnetic recording medium 10I is simplified in FIG. 10 so as to have only four linear magnetic wires 1 and the insulating layer 4 and the substrate 2 are omitted. Like the magnetic recording medium 10 according to the first embodiment, the magnetic recording medium 10I has a structure in which magnetic thin wires 1, 1,... Are arranged side by side on the substrate 2 and an insulating layer 4 is provided therebetween. As will be described later, the magnetic fine wires 1 and 1 are narrowly arranged in parallel. Further, in the magnetic recording medium 10I, the magnetic thin wire 1 is changed in direction one by one and the positive electrode 31 and the negative electrode 32C are exchanged so that the pulse current (scanning current Isc) is supplied. It is connected to the. Hereinafter, in FIG. 10A, the magnetic thin wire 1 supplied with the current Isc from the right hand to the left hand (referred to as the forward direction) is magnetic thin wire 1A, and the magnetic thin wire 1 supplied with the current Isc in the opposite direction is magnetic thin wire 1B. Called. That is, the magnetic recording medium 10I is alternately arranged in parallel with the magnetic thin wires 1A, 1B, 1A, 1B.

As will be described later, in the magnetic recording medium 10I, the current Isc is simultaneously supplied to the two adjacent magnetic thin wires 1, 1 (1A, 1B), thereby generating magnetic fields H _A , H _B is applied to the other magnetic wire 1 (see FIG. 10B). For this purpose, the distance between the magnetic wires 1 and 1 (1A, 1B) is set to 40 nm or less and 3 nm or more in the same manner as between the magnetic wires 1 and 8B in the magnetic recording medium 10C (see FIG. 6) according to the third embodiment. It is preferable.

  The magnetic wire 1 has the same configuration as that of the first embodiment and the like, and a reproducing area 1r and a writing area 1w are set near both ends. However, in the magnetic recording medium 10I, since the magnetic thin wires 1 (1A, 1B) alternately reverse the direction of the current Isc one by one, the reproducing region 1r and the writing region 1w are respectively magnetic thin wires. 1 is set interchangeably between one end side and the other end side. By adopting such a configuration, the reproducing area 1r and the writing area 1w of the two adjacent magnetic thin lines 1 and 1 that perform recording and reproduction at the same time are set separately at both ends. Even if the interval is narrow, it is easy to make the magnetic heads (data recording unit 5, data reproducing unit 6, not shown) face each other.

Furthermore, in data reproduction, for example, when a magnetic method is applied, magnetic detection by a magnetic head for reproduction (data reproduction unit 6) is performed with magnetic fields from the magnetic wires 1 and 1 adjacent to the selected magnetic thin wire 1 to be reproduced. There is a risk that the accuracy of the lowering. In such a case, the adjacent magnetic wire 1 may be connected to the negative electrode 32C before this so that the adjacent magnetic wire 1 does not face in the reproducing region 1r of the magnetic wire 1. As shown in FIG. 10A, in the vicinity of the reproduction region 1r of the magnetic wire 1A, a nonmagnetic negative electrode 32C connected to the magnetic wire 1B is extended to generate a magnetic field H generated by a current Isc flowing through the negative electrode 32C. _B is applied to the magnetic wire 1A. The same applies to the reproduction region 1r of the magnetic wire 1B. Alternatively, in the reproduction by the magneto-optical method, reproduction is difficult unless the pitch of the magnetic thin wires 1 is equal to or greater than the diffraction limit of the laser beam, so that the adjacent magnetic thin wire 1 in the region facing the reproduction region 1r of the magnetic thin wire 1 By providing a light-shielding film that absorbs light or not providing a reflective film (or providing a reflective film only in the reproduction region 1r), the incident laser light is reflected and emitted only from the reproduction region 1r of the magnetic thin wire 1. do it. That is, in the magnetic recording medium 10I, the pitch of the magnetic wires 1 and 1 (the sum of the width of the magnetic wires 1 and the interval between the magnetic wires 1 and 1) is half the lower limit of the magnetic recording medium 10 and the like according to the first embodiment. It can be said that it can be narrowed.

  In the data recording, if the magnetic field application method is used, for example, the recording magnetic head (data recording unit 5) moves together to the area of the adjacent magnetic wire 1B facing the writing area 1w of the magnetic wire 1A. Even if the magnetization direction is changed, the area of the magnetic wire 1B may be set outside the data storage area. Alternatively, spin injection magnetization reversal may be applied to the recording method.

  In the magnetic recording medium 10I, when the length of the magnetic wire 1 is increased, a deviation due to the delay of the pulse current occurs between both ends of the magnetic wire 1, and synchronization between the opposing magnetic wires 1, 1 (1A, 1B) occurs. Since this is incomplete, the design is made so that this deviation is within a sufficiently small range with respect to the pulse width.

(Magnetic recording / reproducing device)
According to the magnetic recording / reproducing method according to the fifth embodiment, the magnetic field generating current source (the coil power source 9 shown in FIGS. 1, 4, and 5A) is unnecessary as in the third embodiment. However, as shown in FIG. 10A, the magnetic recording / reproducing apparatus 50 (see FIG. 1) includes two scanning current sources 7, each of which is adjacent to two magnetic thin wires 1, 1 (1A, 1B). ) At the same time and in opposite directions. Further, the magnetic recording / reproducing apparatus 50 includes two data recording units 5 and six data reproducing units 6 (see FIG. 3) (or corresponding to magnetization and magnetic detection at two locations), and these two magnetic wires 1A. , 1B are opposed to the respective regions 1w, 1r. In the magnetic recording / reproducing apparatus 50, one scanning current source 7 may be connected to the magnetic thin wires 1 and 1 in parallel with the positive and negative sides reversed (not shown).

(Magnetic recording / reproducing method)
In the magnetic recording / reproducing method according to the fifth embodiment of the present invention, the two adjacent magnetic wires 1 and 1 (1A, 1B) are selected in the selection step, and the magnetic wires 1A are further selected in the magnetic domain moving step. , 1B is the same as the magnetic recording / reproducing method according to the third embodiment except that the magnetic domains of 1B are moved in opposite directions. In this embodiment, a pulse current is supplied to these magnetic wires 1A and 1B so that the peak periods are synchronized. That is, in the magnetic domain moving step, as shown in FIG. 10A, the peak current Isc is supplied to one magnetic wire 1A, and at the same time, the current Isc is also applied to the adjacent magnetic wire 1B with the magnetic wire 1A. It is supplied in the opposite direction. As a result, as shown in FIG. 10B, magnetic fields H _A and H _B are generated so as to rotate about the magnetic fine wires 1A and 1B, respectively. The magnetic fine wire 1A has a magnetic field H _B and a magnetic fine wire 1B. The magnetic field _HA is applied downward to each.

According to the magnetic recording / reproducing method according to the fifth embodiment, a magnetic current 1 is obtained by simultaneously supplying pulse current to two adjacent magnetic thin wires 1 and 1 at a narrow interval and recording and reproducing data in parallel. , 1 is applied with a magnetic field in a substantially vertical direction from the other magnetic wire 1, and the peak current (current Isc) of the pulse current supplied to the magnetic wires 1, 1 can be reduced. As in the third embodiment, if the current Isc is reduced, the magnetic field H (H _A , H _B ) is also reduced, so that a sufficiently reduced current can be obtained while obtaining an effective magnitude of the magnetic field H. The magnetic recording medium 10I is preferably designed such that the material of the magnetic wire 1, the thickness (width and thickness), and the interval between the magnetic wires 1 and 1 are set so as to be Isc.

  A magnetic recording medium 10I that records and reproduces data by the magnetic recording and reproducing method according to the fifth embodiment is configured such that two adjacent magnetic thin wires 1 and 1 are supplied with a pulse current Isc in the same direction. May be. In this case, in the magnetic domain moving step, when the current Isc is simultaneously supplied to the adjacent magnetic wires 1 and 1, the magnetic field H is applied to one magnetic wire 1 upward and to the other magnetic wire 1 downward. Is done. Further, in such a magnetic recording medium, there is no deviation due to the delay of the pulse current between the magnetic thin wires 1 and 1, so that the length of the magnetic thin wire 1 can be increased. In addition, since the write areas 1w and 1w and the reproduction areas 1r and 1r of the adjacent magnetic thin wires 1 and 1 are set close to each other, a recording / reproduction method that can cope with such an arrangement is applied.

  The magnetic recording medium 10I may be provided with a wide interval between two pairs of adjacent magnetic fine wires 1 and 1 that are simultaneously selected, that is, the magnetic fine wires 1 are arranged in parallel with an interval increased every two wires. May be. Further, the magnetic recording medium 10I may have a disk shape (not shown) in which the magnetic fine wires 1 are formed concentrically as in the first and second embodiments.

In the magnetic recording / reproducing method according to the fifth embodiment, two or more sets of two adjacent magnetic thin wires 1 and 1 may be simultaneously selected, and a pulse current may be supplied in parallel to move the magnetic domain. However, the groups to be selected are selected with one pair (two or more) left. In other words, the pulse current is not supplied simultaneously to two or more pairs (four or more adjacent) of magnetic thin wires 1 that are adjacent at equal intervals. For example, when the current Isc is simultaneously supplied to the four magnetic wires 1 (1A, 1B, 1A, 1B) shown in FIG. 10, the second magnetic wire 1B from the left in FIG. from the left end of) the magnetic wire 1A field H _a is upward, downward magnetic field H _a from the right side of the magnetic wire 1A, since each is applied, the magnetic field H _a of opposite, cancel each other are H _a substantially No magnetic field is applied. Similarly, no magnetic field is applied to the third magnetic wire 1A from the left. In this way, since the adjacent magnetic thin wires 1 and 1 are supplied with the current Isc in the same direction, the magnetic fields in opposite directions cancel each other and the magnetic field is not substantially applied, and the magnetic domain does not move with the reduced scanning current Isc. There is a fear. The same applies to the case where the current Isc is supplied to the adjacent magnetic wires 1 and 1 in the same direction. In addition, when the space | interval of the pair of magnetic fine wires 1 and 1 is wide, since the magnetic field applied from the magnetic fine wire 1 of an adjacent group is weaker, it is not this limitation. A method of recording and reproducing data in parallel on four or more adjacent magnetic thin wires 1 will be described in a later modification.

  As in the third embodiment, the magnetic recording medium according to the fifth embodiment can be a pixel array of a spatial light modulator in which linear magnetic thin wires 1 are arranged in parallel, and the magnetic recording according to the present embodiment. Writing to the pixels of the spatial light modulator is possible by the reproduction method. In the spatial light modulator according to this embodiment, since the distance between the magnetic wires 1 and 1 is less than the diffraction limit of incident light, the aperture ratio (the area ratio of the light modulating region in the pixel) is substantially 100. %.

(Modification)
In the magnetic recording / reproducing method according to the fifth embodiment, it has been described that data cannot be recorded and reproduced in parallel with more than two adjacent magnetic wires, that is, three or more adjacent magnetic thin wires. However, by configuring each magnetic wire so that a current is supplied in the opposite direction between the adjacent magnetic wires, a sufficiently large magnetic field is applied to all the adjacent magnetic wires. Data can be recorded and reproduced in parallel with these magnetic wires. Hereinafter, a spatial light modulator and a pixel driving method thereof according to a modification of the fifth embodiment of the present invention will be described with reference to FIG. The same elements as those in the first to fifth embodiments (see FIGS. 1 to 10) are denoted by the same reference numerals, and description thereof is omitted.

The spatial light modulator 10J written to the pixel by the pixel driving method of the spatial light modulator according to the modification of the fifth embodiment includes four or more even numbers on the rectangular plate-like substrate 2 (not shown). Are arranged in parallel. The spatial light modulator 10J is simplified in FIG. 11, and includes only six magnetic thin wires 1. From the front in FIG. 11A (from the left in FIG. 11B), the magnetic thin wire 1 _{DMY is} sequentially arranged. , 1A ₁ , 1B ₁ , 1B ₂ , 1A ₂ , 1 _DMY , and the insulating layer 4 is omitted. In the spatial light modulator 10J according to this modification, the pulse current (scanning current Isc) is supplied by inverting the direction of every two magnetic wires 1. That is, the current Isc is supplied to the magnetic wires 1 _DMY and 1A ₁ in the forward direction, the magnetic wires 1B ₁ and 1B ₂ in the reverse direction, and the magnetic wires 1A ₂ and 1 _DMY in the forward direction.

  Each of the magnetic wires 1 can have the same configuration as the magnetic wire 1 in the spatial light modulator described in the first embodiment. However, in the spatial light modulator 10J, the fine wire length of the magnetic fine wire 1 and the interval between the magnetic fine wires 1 and 1 are the magnetic fine wire 1 (1A, 1A, 1) of the magnetic recording medium 10I (see FIG. 10) according to the fifth embodiment. 1B), the electrodes 31 and 32 are connected to both ends of the magnetic wire 1 in accordance with the direction of the supplied current Isc.

The four magnetic wires 1A ₁ , 1A ₂ , 1B ₁ , 1B ₂ excluding the two magnetic wires 1 _DMY , 1 _DMY at both ends (hereinafter referred to as both edges) in the side-by-side direction (thin wire width direction) are spaces. A pixel of the optical modulator 10J is configured, and a writing area 1w is set on the negative electrode 32 side. These four magnetic thin wires 1 arranged in parallel are arranged in the pixel array (FIG. 11A) in the region excluding the write region 1w and the vicinity of the end facing the write region 1w, that is, in the center of the thin line direction. (Represented by a dotted line). In the present embodiment, each magnetic thin line 1 is formed with a recess 1trp that is divided for each pixel length (unit length) Lb so that four pixels are continuously provided in the thin line direction. That is, the pixel array of the spatial light modulator 10J is composed of 16 pixels of 4 rows × 4 columns.

In the spatial light modulator 10J, the current Isc is supplied in the same direction and data is written in parallel. In the adjacent magnetic thin wires 1B ₁ and 1B ₂ , for example, a magnetic field application method is used for recording. In order to make the magnetic heads (the data recording unit 5, see FIG. 3) face each other, the respective write areas 1w may be shifted in the direction of the thin lines and spaced apart (not shown). The same applies to the case where an electrode or the like is provided by applying spin injection magnetization reversal. When the write areas 1w of the adjacent magnetic thin wires 1 and 1 are shifted in the direction of the thin lines, the magnetic domains generated in the write areas 1w in the respective magnetic thin lines 1 are moved to a predetermined position. It is preferable to shift by an integral multiple of one data (pixel length Lb).

On the other hand, the two magnetic thin lines 1 _DMY and 1 _{DMY on} both edges in the spatial light modulator 10J are magnetic thin lines for generating a magnetic field, and the magnetic thin lines 1A ₁ , 1A ₂ , 1B ₁ , 1B constituting the pixel. All of ₂ are provided to apply a magnetic field from both sides. Therefore, the magnetic thin wires 1 _DMY and 1 _DMY are dummies that do not store data, and can be configured in the same manner as the magnetic thin wires 1A ₁ and 1A ₂ , but the data is not written. The recess 1 trp is unnecessary (may be formed like the recess 1 trp shown in FIG. 11A).

The spatial light modulator 10J according to the present embodiment further includes a data recording section (magnetizing means) 5 (see FIG. 3) and a scanning current source (current supply means) 7. The scanning current source 7 is configured to supply a pulse current to each of all the magnetic wires 1 in a predetermined direction. In FIG. 11A, one scanning current source 7 is connected in parallel to two adjacent magnetic thin wires 1 and 1 to which the current Isc is supplied in the same direction, but this is not restrictive. The data recording unit 5 is provided so as to oppose the respective write areas 1w of the magnetic fine wires 1 except for the dummy magnetic fine wires 1 _DMY and 1 _DMY on both edges (not shown in FIG. 11A).

(Pixel driving method of spatial light modulator)
The pixel driving method of the spatial light modulator according to the modification of the fifth embodiment of the present invention includes selecting a predetermined number (four in this case) of magnetic thin wires 1 adjacent to each other in the selection step, and The magnetic recording according to the fifth embodiment except that in the magnetic domain moving step, current (peak current of pulse current) is also supplied to the magnetic wires 1 _DMY and 1 _DMY on both sides of the selected set of magnetic wires 1. The playback method is the same. Thus, in the magnetic domain movement step (peak time of the pulse current), as shown in FIG. 11 (b), including dummy magnetic wire 1 _DMY, magnetic field H _A of the direction of rotation each magnetic thin wire 1 in the axial, H _B is generated. Specifically, the magnetic wires 1 _DMY , 1A ₁ , 1A ₂ , 1 _DMY to which the current Isc is supplied in the forward direction are surrounded by the magnetic field _HA , and the magnetic wires 1B ₁ and 1B are supplied with the current Isc in the reverse direction. _A magnetic field H _B is generated around ₂ and a magnetic field H _A is generated around the magnetic wires 1A ₂ and 1 _DMY .

At this time, the magnetic thin wire 1A ₁ has a magnetic field _HA from the magnetic thin wire 1 _DMY on the left side (hereinafter the same in FIG. 11B) downward, and a magnetic field H _B from the right magnetic thin wire 1B ₁ downward. Applied. Therefore, a large synthetic magnetic field H _{syn obtained} by synthesizing the magnetic fields H _A and H _B is applied downward to the magnetic wire 1A ₁ . Similarly, the magnetic wire 1B _1, downward magnetic field H _A from the magnetic wire 1A ₁ left, downward magnetic field H _B from the right side of the magnetic wire 1B _2, respectively applied magnetic field H _A, is H _B Synthesis The synthesized magnetic field H _syn applied is applied downward. Magnetic fields H _B and _HA are applied upward to the magnetic thin wires 1B ₂ and 1A ₂ from the left and right, respectively, and a combined magnetic field H _syn obtained by combining the magnetic fields H _B and _HA is applied upward.

In this way, by supplying the current Isc at the same time by changing the direction for every two magnetic wires 1, the adjacent magnetic wires 1, 1 are reversed in the opposite direction with respect to three or more adjacent magnetic wires 1. Since the current Isc flows, the magnetic fields H _A and H _B are applied in the same direction from both sides and synthesized without canceling each other. Therefore, according to the pixel driving method of the spatial light modulator according to the modification of the fifth embodiment, similarly to the magnetic recording / reproducing method according to the fifth embodiment, a magnetic field is generated between the magnetic thin wires 1 that move the magnetic domains in parallel. Since they are applied to each other, the peak current (scanning current Isc) of the pulse current supplied to each magnetic wire 1 can be reduced. In particular, in the present modification, magnetic fields H _A and H _B are applied to the magnetic thin wire 1 from both sides and synthesized, so that the magnetic field (synthetic magnetic field H) applied to the magnetic thin wire 1 without increasing the scanning current Isc. _syn ) can be made large enough. Further, by making the magnetic thin wires 1 and 1 on both edges dummy for storing no data, a magnetic field is applied to both of the other magnetic thin wires 1 from both sides, resulting in a composite magnetic field having the same magnitude. The magnetic domain can be moved by the scanning current Isc.

The pixel driving method of the spatial light modulator according to the modification of the fifth embodiment can be applied to the magnetic recording / reproducing method as in the fifth embodiment. A magnetic recording medium on which data is recorded and reproduced by the magnetic recording / reproducing method according to the present modification is the fifth embodiment of the magnetic thin wire 1 (1A ₁ , 1B ₁ , 1B ₂ , 1A ₂ ) shown in FIG. The reproduction region 1r may be set similarly to the form (see FIG. 10 (a)), and the magnetic wires 1 may be formed concentrically. In such a magnetic recording medium, the two outermost and innermost wires are dummy magnetic wires 1 _DMY and 1 _DMY .

In the pixel driving method or magnetic recording / reproducing method of the spatial light modulator according to the modification of the fifth embodiment, data is recorded in parallel on all the magnetic wires 1 (except for the dummy magnetic wires 1 _DMY and 1 _DMY ). There is no need to replay. Specifically, recording and reproduction may be performed in parallel only on the adjacent n magnetic thin wires 1, and at this time, the adjacent number of the n magnetic thin wires 1 and the magnetic thin wires 1 and 1 on both outer sides thereof are measured. A pulse current is simultaneously supplied to (n + 2) lines. At this time, the magnetic thin wires 1 and 1 on both outer sides are dummies for generating a magnetic field, and the magnetic field is only on one side so that the shift is not performed when data is already recorded (a magnetic domain is generated). In this state, the current Isc is adjusted to a current density that does not move the domain wall. Or it is good also as a magnetic recording medium provided with the dummy magnetic wire _1DMY for every n (one per (n + 1)).

  In this modification, the number of pairs of magnetic thin wires 1 that can record and reproduce data in parallel is at least two (n ≧ 2), and two magnetic thin wires are provided on both sides as a dummy. Since it is necessary to supply a pulse current to 1 as well, since the total amount of current to be used increases with two, it is preferable to use four or more.

  As described above, according to the magnetic recording / reproducing method and the spatial light modulator according to the fifth embodiment of the present invention and the modification thereof, the recording / reproducing of data is performed using the magnetic thin line on which data is recorded as the magnetic field applying unit. The current used at the time can be reduced, and the deterioration of the magnetic wire of the magnetic recording medium or the spatial light modulator can be suppressed.

  As described above, the magnetic recording medium device, the magnetic recording / reproducing method, and the form for implementing the spatial light modulator according to the present invention have been described, but the present invention is not limited to these embodiments, and claims Various modifications are possible within the range shown in.

10,10A~10I magnetic recording medium 10J spatial light modulator 1 magnetic wire 1A, 1B magnetic wire _{1A 1, 1A 2, 1B 1} , 1B 2 magnetic wire 1 _DMY magnetic wire 1trp recess 1r reproducing area 1w writing area 20,20A Magnetic recording medium device 2 Substrate 31, 31B electrode, positive electrode 32, 32B, 32C electrode, negative electrode 4 Insulating layer 50, 50A Magnetic recording / reproducing device 5 Data recording unit (magnetizing means)
6 Data reproduction unit (magnetic detection means)
7 Scanning current source (current supply means)
80, 80A coil (magnetic field applying means)
8,8A conductor _{8B, 8B 1, 8B 2,} 8B 3, 8C, 8D A, 8D B wire (magnetic field applying means)
9 Coil power supply (magnetic field generating current source)

Claims (11)

Provided with a magnetic thin line formed by forming a magnetic film having perpendicular magnetic anisotropy into a thin line shape, binary data is recorded continuously in the thin line direction of the magnetic thin line in one of two different magnetization directions. A magnetic recording medium device for recording or reproducing binary data on a magnetic recording medium,
Magnetizing means for magnetizing a designated area provided at a predesignated position in the magnetic wire in one of the two magnetization directions based on binary data, and a magnetic detecting means for detecting the magnetization direction in the designated area And at least one of
Current supply means for supplying a pulse current for intermittently moving in the direction of the thin wire to the magnetic thin wire, a magnetic wall separating the magnetic domains formed in the magnetic thin wire;
Magnetic field applying means for applying a magnetic field of a magnitude that does not change the magnetization direction of the magnetic wire to the magnetic wire in the vertical direction or the direction of the wire width of the magnetic wire;
The magnetic recording medium device, wherein the magnetic field applying means applies the magnetic field to a magnetic wire to which the pulse current is supplied at least during a peak period of the pulse current.   The magnetic recording medium device according to claim 1, wherein the magnetic field applying unit includes one or more coils and a magnetic field generation current supply unit that supplies a current that generates the magnetic field to the coils.   The magnetic field applying means supplies a conductive wire formed in parallel to the magnetic wire via an insulating film to at least one of the upper and lower sides of the magnetic wire of the magnetic recording medium, and a current for generating the magnetic field to the conductive wire The magnetic recording medium device according to claim 1, further comprising a magnetic field generating current supply unit configured to operate. The conducting wire is provided for each magnetic wire of the magnetic recording medium and connected in series to the magnetic wire,
4. The magnetic recording medium device according to claim 3, wherein the current supply means is the magnetic field generation current supply means. A plurality of magnetic thin wires formed by forming magnetic films having perpendicular magnetic anisotropy in the shape of thin wires are arranged side by side, and binary data is made continuous in the thin wire direction of the magnetic thin wires in one of two different magnetization directions. A magnetic recording medium device for recording or reproducing binary data on a magnetic recording medium to be recorded,
Magnetizing means for magnetizing a designated area provided at a predesignated position in the magnetic wire in one of the two magnetization directions based on binary data, and a magnetic detecting means for detecting the magnetization direction in the designated area And at least one of
A current supply means for supplying a pulse current for intermittently moving a domain wall separating the magnetic domains formed in the magnetic thin wire in the direction of the thin wire, in each of the magnetic thin wires;
The current supply means supplies the pulse current in one direction to one of the magnetic thin wires to be operated by the magnetizing means or the magnetic detection means, and at the same time, applies the pulse current to one or both of the adjacent magnetic thin wires. And the pulse current is not supplied in the same direction between the two adjacent magnetic thin wires. A magnetic recording medium device for recording or reproducing data in parallel with respect to adjacent n (n is an even number of 2 or more) magnetic thin wires in the magnetic recording medium,
The current supply means supplies the pulse current to the n magnetic wires and the two adjacent magnetic wires at the same time and with the direction reversed for every two adjacent magnetic wires. The magnetic recording medium device according to claim 5. Provided with a magnetic thin line formed by forming a magnetic film having perpendicular magnetic anisotropy into a thin line shape, binary data is recorded continuously in the thin line direction of the magnetic thin line in one of two different magnetization directions. A magnetic recording / reproducing method for recording or reproducing binary data on a magnetic recording medium comprising:
By supplying a pulse current in which the magnetic domain formed in the magnetic thin line moves intermittently together with the domain wall that divides the magnetic domain, the magnetic thin line is formed in the magnetic thin line at the time of current supply in the pulse current. A magnetic domain moving step is performed in which the magnetic domain is moved a distance corresponding to the length of one of the data in the direction of the thin line,
When the current in the pulse current is stopped, a magnetizing step of magnetizing a designated area provided at a position designated in advance in the magnetic wire in one of the two magnetization directions based on binary data, or in the designated area Perform a magnetic detection process to detect the magnetization direction,
The magnetizing step or the magnetic detection step, and the magnetic domain movement step are alternately repeated, and data is sequentially recorded or reproduced with respect to the magnetic wire,
A magnetic recording / reproducing method, wherein at least in the magnetic domain moving step, a magnetic field having a magnitude that does not change the magnetization direction of the magnetic wire is applied to the magnetic wire in the vertical direction or the width direction of the magnetic wire. A plurality of magnetic thin wires formed by forming magnetic films having perpendicular magnetic anisotropy in the shape of thin wires are arranged side by side, and binary data is made continuous in the thin wire direction of the magnetic thin wires in one of two different magnetization directions. A magnetic recording / reproducing method for recording / reproducing binary data on / from a magnetic recording medium to be recorded,
Performing a selection step of selecting one or more magnetic wires from the magnetic recording medium;
By supplying to the selected magnetic thin wire a pulse current in which the magnetic domain formed in the magnetic thin wire moves intermittently together with the domain wall that divides the magnetic domain, the magnetic thin wire is formed at the time of current supply in the pulse current. A magnetic domain moving step is performed in which the magnetic domain is moved a distance corresponding to the length of one of the data in the direction of the thin line,
A magnetization step of magnetizing a designated region provided at a position designated in advance in each of the selected magnetic thin wires in one of the two magnetization directions based on binary data when the current in the pulse current is stopped; or Performing a magnetic detection step of detecting the magnetization direction in the designated region;
The magnetizing step or the magnetic detection step, and the magnetic domain movement step are alternately repeated, and data is sequentially recorded or reproduced with respect to the selected magnetic wire,
The pulse current is supplied to one of the selected magnetic wires in one direction, and at the same time, the pulse current is supplied to one or both of the magnetic wires adjacent to the one magnetic wire, and the pulse current is supplied to both the adjacent wires. The magnetic recording / reproducing method is characterized in that the magnetic thin wires are not supplied in the same direction. The selection step selects n (n is an even number of 2 or more) adjacent magnetic fine wires from the magnetic recording medium,
The magnetic domain moving step is characterized in that the pulse current is supplied to the n magnetic wires and the two adjacent magnetic wires at the same time, with the direction reversed for every two adjacent magnetic wires. The magnetic recording / reproducing method according to claim 8. A magnetic recording medium device according to any one of claims 1 to 6 and the magnetic recording medium,
A spatial light modulator comprising a plurality of magnetic thin wires arranged in parallel on the magnetic recording medium as a pixel array in which pixels are two-dimensionally arranged.   7. A spatial light modulator comprising a plurality of magnetic thin wires formed by forming magnetic films having perpendicular magnetic anisotropy in the form of thin wires in parallel to form a pixel array in which pixels are arranged in a matrix. 10. A spatial light modulator that uses the magnetic recording / reproducing method according to claim 9 to make each pixel of the pixel array have one of two different magnetization directions based on binary data input to the pixel. Pixel driving method.