Spin wave waveguide structure body

Abstract

To provide a spin wave waveguide structure body capable of performing waveguide of a spin wave without changing a shape of magnetic material.SOLUTION: A spin wave waveguide structure body comprises: an insulating magnetic body membrane; and a periodic electrical conduction body membrane that is disposed on at least one of both surfaces of the insulating magnetic body membrane and is composed of an electrical conduction body membrane having a periodic structure. In the periodic structure of the periodic electrical conduction body membrane, the electrical conduction body membrane is composed of an aggregate of a plurality of small piece membranes and the small piece membranes are electrically insulated from one another. The insulation depends on the small piece membranes being separated from one another by a plurality of holes and grooves connecting the plurality of holes or existence of non-magnetic and non-electrical conductive material in at least some of the holes and the grooves. On the insulating magnetic body membrane, part having the periodic electrical conduction body membrane and part not having the electrical conduction body membrane exist. The insulating magnetic body membrane at the part not having the electrical conduction body membrane functions as a spin wave waveguide.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a spin-wave waveguide structure. [Background technology]

[0002] In recent years, the rapid increase in the amount of information on the Internet and artificial intelligence has led to the demand for continuous growth in electronic devices. Until now, performance improvements have been achieved through miniaturization and integration of electronic devices, but as miniaturization approaches the physical limit, the problem of heat generation has become more pronounced, resulting in a situation in which improvements in device performance are being hindered. This heat generation is caused by Joule heat generated when electrons move through a conductor, and it is thought that this problem can be solved if a device that processes information without moving electrons can be realized. Therefore, attention is being paid to devices using spin waves that can propagate through insulators that do not conduct electricity without the movement of electrons. However, the development of devices using spin waves has only attracted attention rapidly over the past decade, and basic components such as spin wave propagation elements and rudimentary logic elements have been steadily developed, so it can be said that as of 2023, it is still in its infancy.

[0003] Against this background, methods and structures for realizing waveguides, the most basic element of spin wave devices (spin wave circuits), have been developed. Spin wave waveguides are equivalent to electric wires (wiring) in electronic circuits and can be said to be essential. Spin waves are phase waves created by magnetization (spin) in magnetic materials. They are also called magnetostatic waves. In the explanations of this specification, spin waves are a concept that includes "magnetostatic waves."

[0004] Spin waves propagate only within magnetic materials, not in air. Therefore, by processing magnetic materials into any shape, it becomes possible to wire spin waves. Usually, a waveguide of any shape is made by etching or cutting out a magnetic material. Non-Patent Document 1 introduces an example of making a spin wave waveguide by cutting out a magnetic material into a Ψ shape, as shown in Figure 1. This makes it possible to wire spin waves at any position. However, changing the shape of a magnetic material changes the magnetization state, which changes the propagation strength of the spin wave, resulting in a problem of degraded power efficiency of spin wave devices. This change in magnetization state caused by a change in the shape of a magnetic material is a principle common to all magnetic materials, and there is no way to avoid it as long as the shape is changed.

[0005] By periodically drilling holes in a magnetic material, a periodic magnetization structure can be created. Among the spin waves propagating through a magnetic material with periodically formed holes, only spin waves of a specific frequency cannot propagate due to phase interference. This range of frequencies that cannot propagate is called a band gap. By creating an area in the periodic structure where there is no periodic structure, spin waves can propagate along that line. Non-Patent Document 2 is a paper that experimentally demonstrates this. However, since the shape of the magnetic material in Non-Patent Document 2 is changed, the propagation strength of the spin waves changes, as in the case of Non-Patent Document 1, and the power efficiency of the spin wave device is significantly degraded. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Naoki Kanazawa, Taichi Goto, Koji Sekiguchi, Alexander B. Granovsky, Caroline A. Ross, Hiroyuki Takagi, Yuichi Nakamura, Hironaga Uchida and Mitsuteru Inoue, "The role of Snell's law for a magnonic majority gate", Scientific Reports, 7, 7898 (2017 / 08 / 11). [Non-Patent Document 2] Y. Zhu, KH Chi and CS Tsai, "Magnonic crystals-based tunable microwave phase shifters", Applied Physics Letters, 105, 022411 (2014). Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, a spin wave waveguide is necessary to realize spin wave wiring. The structures of Non-Patent Document 1 and Non-Patent Document 2 are disclosed for fabricating a spin wave waveguide. However, in both the structures of Non-Patent Document 1 and Non-Patent Document 2, it is necessary to change the shape of the magnetic material by processing, and it is known that the propagation efficiency (power consumption) of the spin wave deteriorates due to the shape dependency of the magnetic material. For this reason, a structure that controls the guiding direction of the spin wave without changing the shape of the magnetic material has been required. This is the problem of modern spin wave waveguides. In the current situation, an effective structure to solve this problem has not been proposed.

[0008] The present invention has been made in consideration of the above problems, and has an object to provide a spin-wave waveguide structure capable of guiding spin waves without changing the shape of a magnetic material. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a spin-wave waveguide structure for guiding spin waves, comprising an insulating magnetic film and a periodic conductor film made of a conductor film having a periodic structure arranged on at least one of both surfaces of the insulating magnetic film, the periodic structure of the periodic conductor film being such that the conductor film is made of an assembly of a plurality of small piece films, the small piece films being electrically insulated from adjacent small piece films, the electrical insulation of the small piece films being due to the small piece films being separated from each other by a plurality of holes and grooves connecting the plurality of holes, or due to the presence of a nonmagnetic and nonconductive material in at least a portion of the holes and grooves, the spin-wave waveguide structure having a portion on the insulating magnetic film having the periodic conductor film and a portion on the insulating magnetic film not having the conductor film, the insulating magnetic film in the portion not having the conductor film functions as a spin-wave waveguide.

[0010] Such a spin-wave waveguide structure allows for spin-wave guiding without changing the shape of the magnetic material. That is, the portion of the insulating magnetic film that does not have a conductive film can function as a spin-wave waveguide, and spin-wave guiding is possible by changing the location where the conductive film is formed, without changing the shape of the insulating magnetic film.

[0011] Here, it is preferable that the insulating magnetic film is made of magnetic garnet, and more preferably, the insulating magnetic film is made of yttrium iron garnet.

[0012] By using such a type of insulating magnetic film, good spin wave guiding can be achieved.

[0013] The conductive film may contain at least one of copper, aluminum, gold, silver, platinum, iron, a transparent conductor, a superconductor, graphene, carbon nanotubes, an organic conductive material, and a conductive magnetic material.

[0014] In the spin-wave waveguide structure of the present invention, the above-mentioned types of conductors can be used as the conductor component in addition to copper.

[0015] It is also preferable that the insulating magnetic film has a thickness of 1 mm or less.

[0016] It is also preferable that the thickness of the conductive film is 100 μm or less.

[0017] The dimensions of the components of the spin-wave waveguide structure of the present invention are preferably similar to these, allowing miniaturization.

[0018] It is also preferable that the spin-wave waveguide structure further comprises a support substrate, on which the insulating magnetic film and the periodic conductive film are disposed.

[0019] In this way, the spin-wave waveguide structure further includes a support substrate, and thus the structure can have excellent mechanical strength.

[0020] In this case, the support substrate can be at least one of a silicon substrate, a glass substrate, a garnet substrate, a dielectric substrate, a conductive substrate, an insulating substrate, a magnetic substrate, a non-magnetic substrate, a wood substrate, and a stone substrate.

[0021] In the spin-wave waveguide structure of the present invention, in addition to a silicon substrate, the above-mentioned types of substrates can be used as the support substrate.

[0022] The thickness of the supporting substrate is preferably 100 μm or more and 500 μm or less.

[0023] Considering strength and compactness, it is preferable that the thickness of the supporting substrate is within this range.

[0024] Also, a spin wave input section and an output section may be formed in the insulating magnetic film in a portion not including the conductive film.

[0025] A spin-wave waveguide structure having such an input section and an output section can easily input and output spin waves. Effect of the Invention

[0026] The spin-wave waveguide structure of the present invention is capable of guiding a spin wave without changing the shape of the magnetic material. That is, the part of the insulating magnetic film that does not have a conductive film can be made to function as a spin-wave waveguide, and the guiding of a spin wave is possible by changing the location where the conductive film is formed, without changing the shape of the insulating magnetic film. [Brief description of the drawings]

[0027] [Figure 1] 1 is a schematic top view showing an example of a spin-wave waveguide structure of the present invention. [Diagram 2] FIG. 2 is a schematic top view showing an example of a spin-wave waveguide structure of the present invention, and is an enlarged view of a portion surrounded by a dashed line A in FIG. [Diagram 3] FIG. 3 is a cross-sectional view showing an example of a spin-wave waveguide structure of the present invention, and is a cross-sectional view of a portion taken along dashed line B in FIG. [Figure 4] 1 is a cross-sectional view showing an example of an output section that can be formed in a spin-wave waveguide structure of the present invention. [Diagram 5] FIG. 1 is a diagram showing the propagation of spin waves in an embodiment. [Figure 6] 1 is a graph showing the intensity distribution of spin waves measured at the output terminals (output section and comparative output section) of the embodiment. [Figure 7] FIG. 13 is a diagram showing the propagation of spin waves in a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, the present invention will be described in detail with reference to the preferred embodiments, but the present invention is not limited thereto.

[0029] As described above, there has been a demand for a structure that controls the guiding direction of spin waves without changing the shape of a magnetic material. In response to this problem, the inventors have discovered that a specific structure enables spin wave guiding without changing the shape of a magnetic material, and have completed the present invention.

[0030] The present invention is a spin-wave waveguide structure for guiding spin waves, comprising an insulating magnetic film and a periodic conductor film made of a conductor film having a periodic structure arranged on at least one of both surfaces of the insulating magnetic film, the periodic structure of the periodic conductor film being such that the conductor film is made of an assembly of a plurality of small film pieces, the small film pieces being electrically insulated from adjacent small film pieces, the electrical insulation of the small film pieces being due to the small film pieces being separated from each other by a plurality of holes and grooves connecting the plurality of holes, or due to the presence of a nonmagnetic and nonconductive material in at least a portion of the holes and grooves, the spin-wave waveguide structure having a portion on the insulating magnetic film having the periodic conductor film and a portion on the insulating magnetic film not having the conductor film, the insulating magnetic film in the portion not having the conductor film functions as a spin-wave waveguide.

[0031] The present invention will be further described with reference to the drawings. Fig. 1 is a schematic top view showing an example of a spin-wave waveguide structure of the present invention. Fig. 2 is an enlarged view of a portion surrounded by a dashed line A in Fig. 1. Fig. 3 is a cross-sectional view of a portion surrounded by a dashed line B in Fig. 2. Fig. 4 is a cross-sectional view showing an example of an output section.

[0032] The spin-wave waveguide structure 100 shown in FIGS. 1 to 4 has an insulating magnetic film 12 and a periodic conductive film 14. The periodic conductive film 14 is disposed on at least one of both surfaces of the insulating magnetic film 12. Here, as shown in the cross-sectional view of FIG. 3, an example is shown in which the periodic conductive film 14 is formed on both surfaces of the insulating magnetic film 12. Furthermore, as shown in FIGS. 1 and 2, the periodic conductive film 14 has a periodic structure. Moreover, the periodic structure of the periodic conductive film is such that the conductive film is composed of a collection of small film pieces 14a separated by a plurality of holes 15 and grooves 16 connecting the plurality of holes 15, and the small film pieces 14a are electrically insulated from the adjacent small film pieces 14a by these holes 15 and grooves 16.

[0033] As shown in Fig. 1, the spin-wave waveguide structure 100 has a portion having a periodic conductor film 14 on the insulating magnetic film 12, and a portion having no conductor film on the insulating magnetic film. The insulating magnetic film 12 in the portion having no conductor film functions as a spin-wave waveguide. In Fig. 1, the spin-wave guiding direction 21 is indicated by a dashed line. The portion of the insulating magnetic film 12 that functions as a spin-wave waveguide needs to have no conductor film, regardless of periodicity.

[0034] With such a structure, a spin-wave waveguide structure capable of guiding spin waves can be obtained without changing the shape of the magnetic material (insulating magnetic film 12).

[0035] 1 is an example in which a spin wave input section 22 and an output section 24 are formed in the insulating magnetic film 12 in a portion not including a conductive film. A spin wave waveguide structure having such an input section 22 and an output section 24 can easily input and output a spin wave.

[0036] In the example of FIG. 1, a portion not having a conductive film, i.e., a spin-wave waveguide, is formed between the input section 22 and the output section 24, and the spin-wave waveguide is bent between the input section 22 and the output section 24. The bending angles α and β are 120° in FIG. 1, but other angles are also possible. For example, it is possible to fabricate a waveguide that is bent at a right angle by setting the bending angles α and β to 90°. The bending angles α and β can also be less than 90°, and it is also possible to place the output terminal so as to return to the side of the input terminal, for example, at 10°. Note that FIG. 1 shows an example in which an output section is also provided in the portion having the periodic conductive film 14 (the portion that is not a spin-wave waveguide) as the comparison output section 26, but as described later, spin waves are hardly propagated in this comparison output section 26.

[0037] The spin-wave waveguide structure 100 shown in FIG. 1 has an insulating magnetic film 12 in all regions including the input section 22 and the output section 24. The insulating magnetic film 12 is made of a magnetic material, and is preferably made of magnetic garnet, and is particularly preferably made of yttrium iron garnet (commonly known as YIG). Magnetic materials such as YIG are inherently ones through which spin waves propagate, and spin waves propagate in the xy plane in FIG. 1. If the insulating magnetic film 12 in FIG. 1 does not have any conductive film 14, the spin waves would propagate without restriction, but the structure shown in FIG. 1 makes it possible to restrict the propagation of the spin waves to a path that functions as a spin-wave guide.

[0038] YIG is a magnetic material, an insulator, and a magnetic insulator. YIG is Y3Fe5O 12 The material may be based on this, with the Y and Fe portions substituted with other elements. What is important about the material for the insulating magnetic film 12 of the present invention is that it is a magnetic material and an insulator, and magnetic garnets are particularly preferred. Among these, YIG is particularly known for its small damping constant, and a small damping constant results in little dissipation of spin waves, allowing for good spin wave propagation. The damping constant of the material forming the insulating magnetic material is 1×10 -3 Below, 1×10-7 The above is preferred.

[0039] In the spin-wave waveguide structure 100 of the present invention, the thickness of the insulating magnetic film 12 can be set to 1 mm or less. Such a thickness is sufficient, and the spin-wave waveguide structure can be made compact. There is no particular lower limit to the thickness of the insulating magnetic film 12, but for example, it can be set to 0.01 μm or more for reasons such as ease of processing.

[0040] In the spin-wave waveguide structure 100 of the present invention, the periodic conductive film 14 may be made of any conductive material, including at least one of copper, aluminum, gold, silver, platinum, iron, transparent conductors, superconductors, graphene, carbon nanotubes, organic conductive materials, and conductive magnetic materials. Among these, copper is particularly preferred.

[0041] As shown in FIG. 1 and FIG. 2, the small piece film 14a is preferably in the shape of a triangle with rounded edges (particularly made of copper). The periodic conductive film 14 is a periodic structure in which the small piece films 14a are periodically arranged. The adjacent small piece films 14a are not in contact with each other and are electrically insulated from each other. If no material is formed between the adjacent small piece films 14a (holes 15 and grooves 16), the material is air, and the adjacent small piece films 14a are electrically insulated from each other. Since it is only necessary to insulate the small piece films 14a from each other, the material between the adjacent small piece films 14a is not particularly limited as long as it is a nonmagnetic and nonconductive material. In other words, the electrical insulation between the small piece films 14a can also be achieved by the presence of a nonmagnetic and nonconductive material in at least a part of the holes 15 and grooves 16. Examples of the material between the adjacent small piece films 14a include glass, silicon, silicone, and plastic. The nonmagnetic and nonconductive material may fill all of the holes 15 and the grooves 16, or may be present only in parts of the holes 15 and the grooves 16. Figures 1 to 3 show a case where nothing is particularly formed between adjacent small piece films 14a.

[0042] The periodic conductive film 14 consisting of a large number of small pieces of film 14a can have the following dimensions. As shown in FIG. 2 and FIG. 3, the size of the hole 15 is d, the width of the straight groove 16 connecting the holes 15 is g, and the center distance between the two holes 15 is a. Since the adjacent holes 15 are connected by the straight groove 16, the small pieces of film 14a are not in contact with each other and are isolated. The size of the structure (d, g, a, the thickness of the conductive film, and the thickness of the insulating magnetic film 12) varies depending on the frequency and wavelength of the spin wave and the physical properties of the magnetic material constituting the insulating magnetic film 12. When the insulating magnetic film 12 is YIG and has a thickness of 10 μm, and the material of the periodic conductive film 14 is copper, the constants d, g, and a can be more specifically set to 250 μm, 1 μm, and 450 μm, respectively.

[0043] The periodic conductive film 14 preferably has a thickness of 100 μm or less. Such a thickness is sufficient for the periodic conductive film 14, and allows miniaturization. There is no particular lower limit to the thickness of the periodic conductive film 14, but it may be set to 0.001 μm or more, for example, for reasons of ease of processing.

[0044] As a more specific example, the periodic structure of the spin-wave waveguide structure 100 can be such that both the upper and lower surfaces are covered with 2 μm thick copper (conductor) having periodic holes 15 and grooves 16, as shown in Figures 1 to 3.

[0045] Spin wave guidance is possible even if the periodic conductive film 14 is formed on only one side of the insulating magnetic film 12. However, it is preferable that the periodic conductive film 14 exists on both sides at the same time. This is because it is easier to control the guidance of spin waves. When the periodic conductive film 14 exists on both sides of the insulating magnetic film 12, it is preferable that the periodic conductive films 14 exist symmetrically on both sides with the insulating magnetic film 12 as the boundary.

[0046] The entire device of the spin-wave waveguide structure 100 of the present invention may be formed on a support substrate. That is, the spin-wave waveguide structure 100 may further include a support substrate (not shown), on which the insulating magnetic film 12 and the periodic conductive film 14 are disposed. By further including a support substrate, the spin-wave waveguide structure 100 can have excellent mechanical strength. The support substrate is preferably at least one of a silicon substrate, a glass substrate, a garnet substrate, a dielectric substrate, a conductive substrate, an insulating substrate, a magnetic substrate, a non-magnetic substrate, a wood substrate, and a stone substrate. The thickness of the support substrate may be 100 μm or more and 500 μm or less. More specific preferred examples of the support substrate include a silicon substrate, a glass substrate, and a garnet substrate each having a thickness of several hundreds μm.

[0047] As shown in FIG. 1 and FIG. 4, the conductor film 23 of the input section and the conductor film 25 of the output section can be formed on the upper part of the magnetic film 12 of the input section 22 (input terminal) and the output section 24 (output terminal), respectively. The conductor film 23 of the input section and the conductor film 25 of the output section can be, for example, a gold film having a thickness of 30 nm. This gold film suppresses extra reflected spin waves generated at the ends of the input terminal and the output terminal. These films are provided to make it easier to confirm the performance of the spin wave guide periodic structure, and are well-known structures that appear in Non-Patent Document 1. The conductor film 23 of the input section and the conductor film 25 of the output section can be made of at least one of gold, copper, aluminum, silver, platinum, iron, transparent conductor, superconductor, graphene, carbon nanotube, organic conductive material, and conductive magnetic material.

[0048] The dimensions of the input section 22 and the output section 24 are arbitrary, but D1 in Figures 1 and 4 can be set to 2 mm, D2 to 2 mm, and D3 to 0.3 mm. The dimensions of the comparative output section 26 and its conductive film 27 are also similar. EXAMPLES

[0049] The present invention will be described in more detail below by showing examples and comparative examples of the present invention, but the present invention is not limited to these examples.

[0050] [Example] A spin-wave waveguide structure according to the present invention, as shown in Figs. 1 to 4, was fabricated. The material of the insulating magnetic film 12 was YIG, and the material of the periodic conductive films 14 arranged on both sides of the insulating magnetic film 12 was copper. The periodic conductive films 14 on both sides of the insulating magnetic film 12 were symmetrical with respect to the insulating magnetic film 12. The conductive film 23 of the input section 22, the conductive film 25 of the output section 24, and the conductive film 27 of the comparative output section 26 were all gold films. The physical properties of each material are as follows: [Physical properties of YIG] Dielectric constant: 15.3 (dimensionless) Saturation magnetization: 1735G Gyromagnetic constant (=magnetic rotation ratio): 2.8MHz / Oe Damping constant: 1×10 -5 (dimensionless) A bias magnetic field was applied to the YIG. Bias magnetic field: applied uniformly to the YIG in the z direction. Magnitude is 2335 Oe. [Physical properties of gold] Conductivity: 4.561×10 7 S / m [Physical properties of copper] Conductivity: 5.96 x 10 7 S / m

[0051] The insulating magnetic film 12 had a thickness of 10 μm, and the periodic conductive film 14 had a thickness of 2 μm. The holes 15 and grooves 16 in the periodic conductive film 14 had a constant d of 250 μm, g of 1 μm, and a of 450 μm. The dimensions of the input section 22, the output section 24, and the comparative output section 26 were D1, D2, and D3, respectively, of 2 mm, 2 mm, and 0.3 mm. The gold films on the input section 22, the output section 24, and the comparative output section 26 had a thickness of 30 nm. The width of the portion (spin-wave waveguide) that did not have a conductive film formed between the input section 22 and the output section 24 was 6 mm, and the bending angles α and β were 120°.

[0052] A spin wave was input to the input section 22 of the spin-wave waveguide structure 100.

[0053] To show the state of spin waves propagating through the above structure, microstrip antennas were installed at the input and output terminals, and the magnetic field signals generated by the spin waves were converted into electrical signals. The results are shown in Figure 5. The shade of color indicates the spin wave intensity. The observed frequency is 1.8 GHz.

[0054] 6 shows the intensity distribution of the spin waves measured in the output section 24 and the comparative output section 26. The average value in the output section 24 was 50 A / m, and the average value in the comparative output section 26 was 15 A / m. It can be said that the spin waves were controlled to flow in the output section 24.

[0055] [Comparative Example] For comparison, Figure 7 shows the state of spin waves when there is no periodic structure formed by the periodic conductive film 14. This is a structure in which there is no copper above or below the YIG. There is YIG, and there is also gold film at the input / output terminals. All dimensions are the same. The bias magnetic field applied to the YIG and the frequency of the spin waves observed are also the same as in the example.

[0056] In the absence of a periodic structure, the spin waves input from the input section 22 of the input terminal have the largest straight-line component, increasing the intensity of the output section 26. At the same time, the spin waves spread during propagation, so they are reflected at the ends of the YIG and spread throughout the entire YIG.

[0057] [Evaluation of Examples and Comparative Examples] In the structure of the comparative example, the direction of travel of the spin wave cannot be restricted, but the periodic structure of the embodiment restricts and controls the direction of travel of the spin wave, and the spin wave can be transmitted to the output section 24. This makes it possible to increase the strength of the output section 24. That is, this embodiment shows that the guide of the spin wave can be performed by the periodic structure. It is desirable that both the copper on the upper part of the YIG and the copper on the lower part are present at the same time. However, the guide of the spin wave can be performed even if only one of them is present. However, the output ratio of the output section 24 and the comparative output section 26 is better in the embodiment having the copper film on both sides as shown above than in the case of only one side. In the embodiment, the bending angle of the waveguide was 120°, but as mentioned above, it is also possible to fabricate a waveguide with other angles. In addition, although the embodiment has one waveguide, the structure of the present invention can be applied to the case where one waveguide is divided into three or many, as in Non-Patent Document 1. [Industrial Applicability]

[0058] Spin wave devices, which are expected to become the next generation of computing, require a technology to wire spin waves. Since spin waves propagate through magnetic materials, conventional spin wave wiring has been achieved by forming magnetic materials into wire-like shapes. This imitates the shape of electrical wiring in electronic devices. However, when the shape of the magnetic material in spin wave devices is changed, like that of an electric wire in electrical wiring, the magnetic properties unique to the magnetic material, called shape magnetic anisotropy, change, causing the propagation properties of the spin waves to change and the propagation efficiency to deteriorate significantly. This invention solves this problem by creating a periodic structure of a conductor on or under the magnetic material, or both, without changing the shape of the magnetic material. This method is expected to become the standard for spin wave wiring in spin wave devices in the near future.

[0059] The spin-wave waveguide structure of the present invention has the following ripple effects in related fields.

[0060] (1) Computer This will have a ripple effect on all fields that currently use computers and on devices that use CPUs and other computing elements. It will be particularly useful in situations where computers are needed on the millimeter or micrometer scale. Examples include sensors and microchips that are being installed in mobile devices, wearable devices, and home appliances.

[0061] (2) High frequency, wireless and communications fields Like microwaves, spin waves are waves that respond on the order of GHz, but by converting them into waves that propagate through magnetic materials, the wavelength can be shortened by more than 100 times. In terms of device (element) size, this means that the entire chip can be made 100 times smaller. Until now, there has not been much progress in miniaturizing analog high-frequency devices, and they are still far from being portable. Therefore, the realization of spin wave devices is expected to lead to the miniaturization of high-frequency devices.

[0062] The present specification includes the following aspects. [1]: A spin-wave waveguide structure for guiding spin waves, comprising: an insulating magnetic film; and a periodic conductor film, the periodic conductor film being made of a conductor film having a periodic structure arranged on at least one of both surfaces of the insulating magnetic film; the periodic structure of the periodic conductor film is such that the conductor film is made of an assembly of a plurality of small film pieces, the small film pieces being electrically insulated from adjacent small film pieces, the electrical insulation of the small film pieces being due to the small film pieces being separated from each other by a plurality of holes and grooves connecting the plurality of holes, or due to the presence of a nonmagnetic and nonconductive material in at least some of the holes and grooves; the spin-wave waveguide structure has a portion on the insulating magnetic film having the periodic conductor film and a portion on the insulating magnetic film not having the conductor film, and the insulating magnetic film in the portion not having the conductor film functions as a spin-wave waveguide. [2]: The spin-wave waveguide structure according to the above [1], wherein the insulating magnetic film is made of magnetic garnet. [3]: The spin-wave waveguide structure according to [2], wherein the insulating magnetic film is made of yttrium iron garnet. [4]: The spin-wave waveguide structure according to any one of [1] to [3] above, wherein the conductive film comprises at least one of copper, aluminum, gold, silver, platinum, iron, a transparent conductor, a superconductor, graphene, a carbon nanotube, an organic conductive material, and a conductive magnetic material. [5]: The spin-wave waveguide structure according to any one of [1] to [4] above, wherein the insulating magnetic film has a thickness of 1 mm or less. [6]: The spin-wave waveguide structure according to any one of [1] to [5] above, wherein the conductive film has a thickness of 100 μm or less. [7]: The spin-wave waveguide structure further comprises a support substrate; The spin-wave waveguide structure according to any one of [1] to [6] above, wherein the insulating magnetic film and the periodic conductive film are disposed on the supporting substrate. [8]: The spin-wave waveguide structure according to [7], wherein the supporting substrate is at least one of a silicon substrate, a glass substrate, a garnet substrate, a dielectric substrate, a conductive substrate, an insulating substrate, a magnetic substrate, a non-magnetic substrate, a wood substrate, and a stone substrate. [9]: The spin-wave waveguide structure according to [7] or [8] above, wherein the thickness of the support substrate is 100 μm or more and 500 μm or less.

[10] : The spin-wave waveguide structure according to any one of [1] to [9] above, wherein a spin-wave input section and an output section are formed in the insulating magnetic film in a portion not having the conductive film.

[0063] The present invention is not limited to the above-described embodiment. The above-described embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included in the technical scope of the present invention. [Explanation of symbols]

[0064] 12...insulating magnetic film, 14...periodic conductive film, 14a...small piece film, 15...hole, 16...groove, 100...spin wave guide structure, 21...Spin wave guiding direction, 22...input portion; 23...conductive film of input portion; 24... output portion; 25... conductive film of output portion; 26...comparison output section, 27...conductive film of comparison output section.

Claims

1. A spin-wave guiding structure for guiding a spin wave, comprising: An insulating magnetic film; a periodic conductive film formed of a conductive film having a periodic structure, the periodic conductive film being disposed on at least one of both surfaces of the insulating magnetic film; having The periodic structure of the periodic conductive film is such that the conductive film is composed of a collection of a plurality of small film pieces, and the small film pieces are electrically insulated from each other from adjacent small film pieces; The electrical insulation of the small film pieces is due to the small film pieces being separated from each other by a plurality of holes and grooves connecting the plurality of holes, or due to the presence of a non-magnetic and non-conductive material in at least a portion of the holes and grooves; a portion having the periodic conductive film on the insulating magnetic film; a portion on the insulating magnetic film that does not have the conductive film; a magnetic insulating film in a portion not including the conductive film, the magnetic insulating film functioning as a spin-wave waveguide.

2. 2. The spin-wave waveguide structure according to claim 1, wherein the insulating magnetic film is made of a magnetic garnet.

3. 3. The spin-wave waveguide structure according to claim 2, wherein the insulating magnetic film is made of yttrium iron garnet.

4. 2. The spin-wave waveguide structure according to claim 1, wherein the conductive film contains at least one of copper, aluminum, gold, silver, platinum, iron, a transparent conductor, a superconductor, graphene, a carbon nanotube, an organic conductive material, and a conductive magnetic material.

5. 2. The spin-wave waveguide structure according to claim 1, wherein the insulating magnetic film has a thickness of 1 mm or less.

6. 2. The spin-wave waveguide structure according to claim 1, wherein the conductive film has a thickness of 100 μm or less.

7. The spin-wave waveguide structure further comprises a support substrate, 7. The spin-wave waveguide structure according to claim 1, wherein the insulating magnetic film and the periodic conductive film are disposed on a supporting substrate.

8. 8. The spin-wave waveguide structure according to claim 7, wherein the support substrate is at least one of a silicon substrate, a glass substrate, a garnet substrate, a dielectric substrate, a conductive substrate, an insulating substrate, a magnetic substrate, a non-magnetic substrate, a wood substrate, and a stone substrate.

9. 8. The spin-wave waveguide structure according to claim 7, wherein the thickness of the support substrate is 100 μm or more and 500 μm or less.

10. 2. The spin-wave waveguide structure according to claim 1, wherein an input section and an output section for spin waves are formed in the insulating magnetic film in a portion not having the conductive film.

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