A spin wave logic device and related circuit

Abstract

A spin wave logic device and related circuits. The spin wave logic device includes a channel, and a drain and source located above the channel. The source is used to generate a spin wave signal. The channel is used to transmit the spin wave signal to the drain. The drain includes a magnetic tunnel junction or a spin valve structure, and is used to exhibit different resistance states based on the spin wave signal, wherein the different resistance states are used to indicate different logical values. The spin wave logic device can detect magnon signals through tunneling magnetoresistance or giant magnetoresistance, preventing information loss after power failure and achieving effective storage of magnon information.

Description

Technical Field

[0001] The present application relates to the field of spin electronics technology, and in particular to a spin wave logic device and related circuits. Background Art

[0002] Spin waves are propagating disturbances in the order of magnetic materials. These low-lying collective excitations occur in magnetic lattices with continuous symmetry. From the perspective of equivalent quasiparticles, spin waves are called magnons (magnons for short), which are bosonic modes of the spin lattice and roughly correspond to phonon excitations of the nuclear lattice. Spin waves can also be considered as collective excited states of spin precession in magnetic material systems, and magnons are quasiparticles that quantize spin waves. Each magnon carries a Planck constant Since magnons have spin angular momentum, they can also carry and transmit spin information like electrons. However, unlike charged particles such as electrons, magnons are electrically neutral and have the advantages of no heat dissipation, low damping, and long-distance spin transmission in insulating magnetic materials. Therefore, they avoid Joule heating caused by charge flow, overcome the increasingly significant problem of device heating, and avoid the adverse effects of increased static power consumption caused by quantum tunneling. Moreover, since the intrinsic frequency of spin waves or magnons is usually in the frequency range of GHz to THz, and the amount of information transmitted and processed is large, magnon devices have potential application prospects in the field of low-power information storage and computing. The magnon transistor is the most typical spin wave logic device. By controlling the conduction and closing of the magnon channel, the two logical states of "0" and "1" can be realized, thereby realizing logical computing functions similar to semiconductor field-effect transistors.

[0003] However, existing methods for detecting information in magnon transistor devices all use the inverse spin Hall effect of heavy metal materials to convert spin signals into voltage signals for detection. However, after power is removed, the information in the magnon transistor device is lost, and the information in the magnon transistor device cannot be read again. Therefore, such magnon transistor devices are volatile. In addition, the voltage signal that can be detected by this detection method is weak, resulting in a detection blind spot. Summary of the Invention

[0004] The present application provides a spin wave logic device and related circuits that are non-volatile.

[0005] In a first aspect, embodiments of the present invention provide a spin wave logic device comprising a channel, a drain electrode, and a source electrode located above the channel. The source electrode is configured to generate a spin wave signal. The channel is configured to transmit the spin wave signal to the drain electrode. The drain electrode comprises a magnetic tunnel junction or a spin valve structure and is configured to exhibit different resistance states in response to the spin wave signal, wherein the different resistance states are configured to indicate different logical values.

[0006] The spin wave logic device provided in the above embodiment of the present invention adopts a magnetic tunnel junction or spin valve structure as the drain. The spin wave logic device can detect the magnon signal through tunneling magnetoresistance or giant magnetoresistance. Since the magnetic tunnel junction or spin valve has the function of not losing information after power failure, the effective storage of magnon information is achieved. Therefore, the spin wave logic device provided in the embodiment of the present invention is non-volatile, meets the demand for calling stored information at any time during the logic operation process, and is conducive to the design of storage and computing integrated devices and device architectures using storage and computing integrated devices. In addition, since the magnetic tunnel junction or spin valve can be miniaturized to the nanometer scale and is compatible with semiconductor processes, the embodiment of the present invention is conducive to device miniaturization.

[0007] In addition, when the source electrode is made of magnetic material, since the magnetic moment arrangement direction of the magnetic material can be parallel or perpendicular to the magnetic metal film, or any angle between parallel and perpendicular to the magnetic metal film, magnetic particles with different polarization directions can be excited. Therefore, the spin wave logic device provided by the embodiment of the present invention has strong controllability and a strong detection signal.

[0008] In another possible implementation, the drain of the spin wave logic device is a magnetic tunnel junction, and the magnetic tunnel junction includes a first magnetic layer, a non-magnetic insulating layer, and a second magnetic layer that are stacked.

[0009] In another possible implementation, the drain of the spin wave logic device is a spin valve structure, and the spin valve structure includes a first magnetic layer, a non-magnetic metal layer, and a second magnetic layer that are stacked.

[0010] In another possible implementation, the drain further includes a first metal layer and a second metal layer, the first metal layer being located between the channel and the first magnetic layer, and the second metal layer being located above the second magnetic layer, and the first and second metal layers being used to supply power. Specifically, the first metal layer may be a bottom electrode, and the second metal layer may be a top electrode. When the first and second metal layers supply power, information in the spin wave logic device can be detected.

[0011] In another possible implementation, the drain electrode further includes a pinning layer located between the second magnetic layer and the second metal layer, the pinning layer being used to fix the magnetic moment direction of the second magnetic layer. In practical applications, the pinning layer may include, but is not limited to, alloy materials such as iridium manganese (IrMn), platinum manganese (PtMn), iron manganese (FeMn), cobalt platinum (CoPt), iron platinum (FePt), and [Co / Pt] n 、[Co / Ni] n And other magnetic multilayer film materials.

[0012] In another possible implementation, the spin wave logic device further includes a gate, which is located between the source and the drain. The gate may include a heavy metal material or a magnetic material, and the gate is used to regulate the transmission of the spin wave signal.

[0013] In yet another possible implementation, the source electrode includes a magnetic metal material or a heavy metal material.

[0014] In another possible implementation, the materials of the first magnetic layer and the second magnetic layer include at least one of the following materials: iron (Fe), cobalt (Co), nickel (Ni), cobalt iron boron (CoFeB), nickel iron (NiFe), cobalt iron (CoFe), cobalt platinum (CoPt), cobalt nickel (CoNi), cobalt terbium (CoTb), cobalt gadolinium (CoGd), [Co / Tb] n 、[Co / Gd] n .

[0015] In another possible implementation, the non-magnetic insulating layer includes at least one of the following materials: manganese oxide MgO, aluminum oxide Al2O3, aluminum nitride AlN, nickel oxide NiO, and manganese aluminum oxide MgAl2O4.

[0016] In yet another possible implementation, the non-magnetic metal layer includes at least one of the following materials: copper (Cu), aluminum (Al), and magnesium (Ag).

[0017] In yet another possible implementation, the thickness of the first magnetic layer and the second magnetic layer are both 1 nm to 10 nm.

[0018] In yet another possible implementation, the thickness of the non-magnetic insulating layer is in a range of 0.7 nm to 10 nm.

[0019] In yet another possible implementation, the thickness of the non-magnetic metal layer is in a range of 0.7 nm to 10 nm.

[0020] In another possible implementation, the source includes a ferromagnetic metal material, a ferrimagnetic metal material, or an antiferromagnetic metal material.

[0021] In another possible implementation, the source electrode includes at least one of the following materials: cobalt Co, nickel Ni, cobalt iron boron CoFeB, nickel iron NiFe, cobalt iron CoFe, cobalt platinum CoPt, cobalt nickel CoNi, [Co / Tb] n 、[Co / Gd] n , iridium manganese IrMn, platinum manganese PtMn, iron manganese FeMn.

[0022] In yet another aspect, embodiments of the present invention provide a circuit comprising one or more spin wave logic devices as described in the first aspect and any implementation of the first aspect. Specifically, the circuit provided by embodiments of the present invention may be a processing circuit, a control circuit, or other circuit. For example, it may include a central processing unit (CPU). BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic structural diagram of a magneton transistor provided by an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of a spin anomalous Hall effect or a planar Hall effect provided by an embodiment of the present invention;

[0025] Figure 3 A schematic diagram and side view of a magnetic moment reversal driven by a magnon torque provided in an embodiment of the present invention;

[0026] Figure 4 A schematic diagram of a magnetic tunnel or spin valve core structure provided by an embodiment of the present invention;

[0027] Figure 5A Schematic diagram of the structure of a spin wave logic device provided by an embodiment of the present invention

[0028] Figure 5B Schematic diagram of another spin wave logic device structure provided by an embodiment of the present invention

[0029] 5C and 5C are cross-sectional schematic diagrams of a spin wave logic device provided by an embodiment of the present invention;

[0030] Figure 6 A schematic flow chart of a method for using a spin wave logic device provided by an embodiment of the present invention;

[0031] Figure 7 A schematic diagram of a circuit structure provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0032] Before introducing a spin wave logic device provided in an embodiment of the present application, the basic concepts involved in the present application are first explained.

[0033] (1) Spin Hall effect:

[0034] Heavy metal films exhibit strong spin-orbit coupling, converting moving electrons (current) into spin signals, which can then excite magnons in magnetic insulators. For example, passing a current I through a platinum (Pt) strip can generate spin signals with opposite spin polarization directions on the top and bottom surfaces of the Pt strip. In embodiments of the present invention, spin signals may also be referred to as spin waves or spin wave signals.

[0035] (2) Spin anomalous Hall effect and planar Hall effect:

[0036] Passing a current I through a magnetic film can generate spin signals on the top and bottom surfaces of the film. Specifically, magnetic films with perpendicular magnetic anisotropy can generate spins via the planar Hall effect, while magnetic films with in-plane anisotropy can generate spins via the spin anomalous Hall effect.

[0037] (3) Magnonic torque effect:

[0038] When spin waves or magnons propagate to the magnetic film, they drive the magnetic moment arrangement of the magnetic film to change direction, thereby storing information non-volatilely in the magnetic layer.

[0039] (4) Magnetic tunnel junction (MTJ)

[0040] A magnetic tunnel junction generally refers to a sandwich structure consisting of a ferromagnetic layer, a nonmagnetic insulating layer, and a ferromagnetic layer. The top ferromagnetic layer is called the reference layer. The nonmagnetic insulating layer is also called the barrier layer. The bottom ferromagnetic layer is called the free layer. The ferromagnetic layer can also be called the magnetic layer.

[0041] (5) Spin transfer torque (STT)

[0042] In a magnetic tunnel junction, when current flows from a reference layer to a weakly magnetic free layer, a spin-polarized current is generated in the reference layer. When this spin-polarized current enters the free layer, it interacts with the magnetic material of the free layer, causing the transverse component of the spin-polarized current to be transferred. This transferred transverse component acts on the free layer in the form of a torque, forcing the magnetization direction of the free layer to approach that of the reference layer. This torque is called spin-transfer torque.

[0043] (6) Magnetic materials, also known as ferromagnetic materials

[0044] Magnetic materials can be magnetized to saturation under a very small magnetic field. The magnetic susceptibility of magnetic materials is greater than zero, and the value of its magnetic susceptibility is greater than 10 to 10 6 In a magnetic material, when the magnetic field disappears, the magnetization state (such as the magnetization direction) in the magnetic material remains unchanged.

[0045] (7) Spin polarization

[0046] Under certain conditions, the spin directions of charged particles such as electrons and atomic nuclei are arranged in a certain direction, thereby generating the probability of magnetism.

[0047] Figure 1 This is a schematic diagram of the structure of a magnon transistor provided in an embodiment of the present invention. As shown in the figure, the magnon transistor includes: a source 111, a magnon channel 112, a drain 113, and a gate 114. The source 111 can be made of a heavy metal material, the magnon channel 112 can be made of a magnetic insulator material, the drain 113 can be made of a heavy metal material, and the gate 114 can be made of a heavy metal or magnetic material.

[0048] The working principle of the magnon transistor may include the following steps: applying a current I to the source (111), and exciting magnons in the channel (112) through the spin Hall effect of the heavy metal material. The magnons propagate in the channel (as shown by the waves) and eventually reach the drain (113). During the propagation of the magnons in the channel, the gate (114) regulates (including enhancing or attenuating) the magnon propagation characteristics, which is equivalent to turning the magnon transistor channel on and off. The drain (113) converts the spin signal into an electrical signal through the heavy metal inverse spin Hall effect, so that detection can be achieved at the drain (113), and the size of the signal detected by the drain represents the two states of "0" and "1", respectively, so that binary logic calculations can be performed. Figure 1 The device configuration shown can be used as a basic spin wave logic device unit. In practical applications, Figure 1 The magnon transistor shown can excite self-magnons in the channel (112) by applying a direct current I to the source (111) through the spin Hall effect of the heavy metal material, or can excite self-magnons in the channel (112) by applying a high-frequency current I to the source (111) through a microwave field.

[0049] However, Figure 1 The magnetic transistor shown detects a voltage signal through the inverse spin Hall effect of the heavy metal strip. The signal disappears after the power is turned off. Therefore, the information data cannot be read again later and is volatile. In addition, the detection end (113) needs to have a y-axis direction (attached Figure 1 ) Only longer heavy metal strips can detect sufficiently large voltage signals. Usually, the length of the strips is on the order of hundreds of microns to millimeters, which is not conducive to device miniaturization and integration.

[0050] To solve Figure 1In order to solve the above-mentioned problems of the magnon transistor shown in the figure, an embodiment of the present invention provides a spin wave logic device with a different structure. It should be noted that the spin wave logic device provided in the embodiment of the present invention can also be called a magnon transistor. The spin wave logic device provided in the embodiment of the present invention can be used as the basic unit of the spin wave logic circuit, which can realize two logical states of 0 and 1. The specific state can be detected by using the magnetoresistance effect and stored in the detection unit in a non-volatile manner. The spin wave logic device provided in the embodiment of the present invention can be used to construct low-power logic computing and storage products that meet specific scenarios. It can be used in artificial intelligence fields such as smart phones, PADs, mobile devices, and can be used to develop a new storage and computing integrated architecture. In the embodiment of the present invention, the spin wave logic device can be called a spin wave logic device unit.

[0051] For the sake of clarity, the following Figure 2 and Figure 3 Several terms of the embodiments of the present invention are exemplarily described. Figure 2 A schematic diagram of a spin anomalous Hall effect or planar Hall effect provided by an embodiment of the present invention. The source (111) is a heavy metal film or a magnetic metal material. As mentioned above, the spin Hall effect means that the heavy metal film has a strong spin-orbit coupling effect, and the moving electrons (current) can be converted into spin signals. For example: Figure 2 As shown, when a current I is passed through a platinum (Pt) strip, spins with opposite spin polarization directions are generated on the upper and lower surfaces of the Pt strip (see Figure 2). Figure 2 Arrow with a ball in the middle)

[0052] Further Figure 2 As shown in Figure 2, the spin-anomalous Hall effect and the planar Hall effect refer to the generation of spins on the upper and lower surfaces of a magnetic film when a current I is passed through the film. Specifically, magnetic films with perpendicular magnetic anisotropy can generate spin signals via the planar Hall effect, while magnetic films with in-plane anisotropy can generate spin signals via the spin-anomalous Hall effect.

[0053] Figure 3 A schematic diagram and side view of a magnon torque-driven magnetic moment reversal in an embodiment of the present invention. Channel 112 is made of a magnetic insulator material, and magnetic layer 104 is made of a magnetic metal film. The magnon torque effect occurs when spin waves or magnons propagate through the magnetic film, driving the magnetic moment arrangement of the film to change direction, thereby non-volatilely storing information in magnetic layer 104.

[0054] Figure 4 Schematic diagram of the core structure of a magnetic tunnel junction or spin valve provided by an embodiment of the present invention. Figure 4As shown, a magnetic tunnel junction or a spin valve may include three layers of material: a first magnetic layer 204, a second magnetic layer 206, and a layer 205 located directly between the first magnetic layer 204 and the second magnetic layer 206. When the structure is the core structure of a magnetic tunnel junction, the layer 205 is an insulating barrier layer. Specifically, the layer 205 may be a non-magnetic insulating layer. When the structure is the core structure of a spin valve, the layer 205 may be a non-magnetic metal layer. Figure 4 Briefly describe the principle of magnetic tunnel junction storage information. Figure 4 As shown, Figure 4 The middle arrow represents the direction of the magnetic moment of the magnetic layer. By controlling the relative orientation of the magnetic moments of the first magnetic layer 204 and the second magnetic layer 206, different resistance states can be achieved. For example, when the magnetic moments of the first magnetic layer 204 and the second magnetic layer 206 are arranged in parallel and in the same direction, the magnetic tunnel junction exhibits a low resistance state, which can be used to indicate a logical value of "0"; when the magnetic moments of the first magnetic layer 204 and the second magnetic layer 206 are arranged in parallel and in opposite directions, the magnetic tunnel junction exhibits a high resistance state, which can be used to indicate a logical value of "1". In this way, information can be stored non-volatilely in the magnetic tunnel junction. It should be noted that the core structure of the spin valve is similar to that of the magnetic tunnel junction. And its principle of storing information is similar to that of the magnetic tunnel junction. In practical applications, in the spin valve, layer 205 can be a non-magnetic conductive metal layer.

[0055] Some technical terms and background of the embodiments of the present invention are introduced above. The spin wave logic device provided by the embodiments of the present invention will be described in detail below. Figure 5A 、 Figure 5B and Figure 5C A schematic diagram of the structure of a spin wave logic device provided by an embodiment of the present invention.

[0056] Figure 5A A schematic structural diagram of a spin wave logic device provided by an embodiment of the present invention is shown in FIG. Figure 5A As shown, the spin wave logic device 200 may include a source 211 , a channel 212 , a drain 213 , a gate 214 , and corresponding wires for implementing current input and voltage detection.

[0057] The source electrode 211 may be a magnetic metal or heavy metal material. Specifically, in one embodiment, the source electrode 211 may be a magnetic metal film material, including ferromagnetic, ferrimagnetic, or antiferromagnetic metal film materials. Ferromagnetic films include, but are not limited to, metals or alloys such as iron (Fe), cobalt (Co), nickel (Ni), cobalt-iron-boron (CoFeB), nickel-iron (NiFe), cobalt-iron (CoFe), cobalt-platinum (CoPt), cobalt-nickel (CoNi), and multilayer films thereof. Ferrimagnetic films include cobalt-terbium (CoTb), cobalt-gadolinium (CoGd) alloys, and [Co / Tb] n 、[Co / Gd] nMultilayer films, etc. Antiferromagnetic films include alloy materials such as iridium manganese IrMn, platinum manganese PtMn, and iron manganese FeMn. When the source 211 is made of a magnetic metal film material, the source 211 needs to have in-plane magnetic anisotropy, perpendicular magnetic anisotropy, or magnetic anisotropy between the two. When the source 211 is a magnetic metal film, the thickness of the source 211 along the z-axis direction can be 0.5 nanometers (nm) to 100 nm. Preferably, the thickness of the source 211 can be in the range of 0.5 nm to 10 nm, and the magnetic metal film of this thickness can generate sufficient current density, thereby generating enough magnetons. In addition, the width of the source 211 along the y-axis can be 1 nm to 100 μm, and the length along the x-axis direction can be 1 nm to 10 micrometers (μm).

[0058] In another case, the source 211 may also be made of non-magnetic strong spin-orbit coupling thin film materials, including but not limited to heavy metal materials. For example, platinum Pt, tungsten W, tantalum Ta and their alloys may be used, and topological insulators and semi-metal materials such as Bi may also be used. 1-x Se x 、Bi 1-x Te x 、W 1-x Te x 、Mo 1-x Te x In practical applications, when the source electrode 211 is made of a non-magnetic, strong spin-orbit coupling thin film material such as a heavy metal material, the thickness of the source electrode 211 along the z-axis can be 0.5 nm to 100 nm. Preferably, the thickness of the source electrode 211 can be in the range of 0.5 nm to 10 nm to generate sufficient current density and thus generate a sufficient number of magnons. In addition, the width of the source electrode 211 along the y-axis can be 1 nm to 100 μm, and the length of the source electrode 211 along the x-axis can be 1 nm to 10 μm.

[0059] The channel 212 may be made of a magnetic insulator material. When a voltage is applied to the source 211, magnons are generated. The magnons are transmitted in the channel 212. The material of the channel 112 may be a magnetic insulator film. Specifically, the material of the channel 212 may include, but is not limited to, yttrium iron oxide YFeO3, yttrium iron garnet (YIG), chromium oxide (Cr2O3), iron oxide (Fe2O3), ferromagnetic oxide (Fe3O4), nickel oxide (NiO), cobalt oxide (CoO), bismuth iron oxide (BiFeO3) and other ferrimagnetic or antiferromagnetic insulators and other magnetic insulator materials. In practical applications, the thickness of the channel 212 along the z-axis direction may be 0.5nm to 100nm, and the width along the y-axis may be 1nm to 20μm. The length of the channel 212 along the x-axis direction can be determined according to actual conditions, for example, it can be 1nm to 20μm. In the embodiment of the present invention, since the channel 212 is used to transmit magnons, the channel 212 may also be referred to as a magnon channel.

[0060] The gate 214 may be a heavy metal or a magnetic material. Specifically, the gate 214 may include but is not limited to heavy metals such as Pt, Ta, W, and their alloys, or may include magnetic film materials, for example, ferromagnetic, ferrimagnetic, or antiferromagnetic metal film materials. Ferromagnetic film materials include but are not limited to metals or alloys such as iron (Fe), cobalt (Co), nickel (Ni), cobalt-iron-boron (CoFeB), nickel-iron (NiFe), cobalt-iron (CoFe), cobalt-platinum (CoPt), and cobalt-nickel (CoNi), as well as multilayer films composed thereof. Ferrimagnetic film materials may include cobalt-terbium (CoTb), cobalt-gadolinium (CoGd) alloys, and [Co / Tb] n 、[Co / Gd] n Multilayer films and other materials. Antiferromagnetic thin film materials may include alloy materials such as iridium manganese (IrMn), platinum manganese (PtMn), and iron manganese (FeMn). In practical applications, the gate 214 may have a thickness along the z-axis of 0.5 nm to 100 nm, a width along the y-axis of 1 nm to 100 μm, and a length along the x-axis of 1 nm to 10 μm.

[0061] The drain 213 may include a magnetic tunnel junction core structure or a spin valve core structure. The drain 213 may include at least a first magnetic layer 204, a non-magnetic insulating layer or a non-magnetic metal layer 205, and a second magnetic layer 206. Among them, the first magnetic layer 204 can serve as a free magnetic layer of a magnetic tunnel junction or a spin valve. The second magnetic layer 206 can serve as a reference magnetic layer of a magnetic tunnel junction or a spin valve. The non-magnetic insulating layer or the non-magnetic metal layer 205 is sandwiched between the first magnetic layer 204 and the second magnetic layer 206. The first magnetic layer 204, the non-magnetic insulating layer or the non-magnetic metal layer 205, and the second magnetic layer 206 form a sandwich structure. The description of the core structure of the magnetic tunnel junction or the spin valve and the information stored therein can be found in the aforementioned Figure 4In the embodiment of the present invention, unless otherwise specified, the non-magnetic metal layer 205 refers to a non-magnetic conductive metal layer.

[0062] In practical applications, magnetic tunnel junctions or spin valves can be limited to Figure 5A The core structure in . Specifically, Figure 5B As shown, Figure 5B A schematic structural diagram of another spin wave logic device provided in an embodiment of the present invention. Figure 5C Schematic cross-sectional view of a spin wave logic device 200 provided in an embodiment of the present invention. Figure 5B As shown, Figure 5B The spin wave logic device 200 shown in FIG. Figure 5A On the basis of the device shown, the drain 213 may further include a pinning layer 207. The pinning layer 207 may include an antiferromagnetic material to fix the magnetic moment direction of the reference magnetic layer 206. Optionally, the drain 213 may further include a first metal layer 203 and a second metal layer 208. The first metal layer 203 may be the bottom conductive electrode (which may be referred to as the bottom electrode) of the magnetic tunnel junction or the spin valve structure. The second metal layer 208 may be the top conductive electrode (which may be referred to as the top electrode) of the magnetic tunnel junction or the spin valve structure. In the embodiment of the present invention, since the first metal layer 203 and the second metal layer 208 play a conductive role, they may also be referred to as the first conductive metal layer 203 and the second conductive metal layer 208.

[0063] In the embodiment of the invention shown in FIG5B , layers 203 to 208 may form a magnetic tunnel junction or a spin valve, wherein the core structure of the magnetic tunnel junction or the spin valve includes a first magnetic layer 204 , a non-magnetic insulating layer or a non-magnetic metal layer 205 , and a second magnetic layer 206 .

[0064] In practical applications, for Figure 5A 、 Figure 5B In the spin wave logic device shown, the materials of the first magnetic layer 204 and the second magnetic layer 206 can be magnetic metal materials, for example, ferromagnetic or ferrimagnetic metal film materials. Specifically, the materials of the first magnetic layer 204 and the second magnetic layer 206 can include, but are not limited to, metals or alloys such as iron (Fe), cobalt (Co), nickel (Ni), cobalt-iron-boron (CoFeB), nickel-iron (NiFe), cobalt-iron (CoFe), cobalt-platinum (CoPt), cobalt-nickel (CoNi), and multilayer films thereof. Ferrimagnetic metal films can include cobalt-terbium (CoTb), cobalt-gadolinium (CoGd) alloys, and [Co / Tb] n 、[Co / Gd] nIn practical applications, the thickness of the first magnetic layer 204 and the second magnetic layer 206 along the z-axis is 1 nm to 10 nm. In practical applications, the first magnetic layer 204 and the second magnetic layer 206 have perpendicular magnetic anisotropy (magnetic moments are represented by arrows, and the magnetic moments are perpendicular to the film). It is understood that the first magnetic layer 204 and the second magnetic layer 206 may also include in-plane magnetic anisotropy, and may also include a magnetic moment arrangement with any angle between perpendicular magnetic anisotropy and in-plane magnetic anisotropy.

[0065] The non-magnetic insulating layer or non-magnetic metal layer 205 includes, but is not limited to, oxide insulators such as manganese oxide (MgO), aluminum oxide (Al2O3), aluminum nitride (AlN), nickel oxide (NiO), and aluminum manganese oxide (MgAl2O4), as well as metals such as copper (Cu), aluminum (Al), and magnesium (Ag), and alloys thereof. In practical applications, the thickness of the non-magnetic insulating layer or non-magnetic metal layer 205 along the z-axis can be 0.7 nm to 10 nm.

[0066] The pinning layer 207 may be an antiferromagnetic material with exchange bias or a magnetic material with large coercivity. The pinning layer 207 is used to fix the magnetic moment direction of the second magnetic layer 206. Specifically, the material of the pinning layer 207 may include, but is not limited to, alloy materials such as iridium manganese (IrMn), platinum manganese (PtMn), iron manganese (FeMn), cobalt platinum (CoPt), iron platinum (FePt), and [Co / Pt] n 、[Co / Ni] n In practical applications, the thickness of the pinning layer 207 along the z-axis direction can be 1 nm to 10 nm.

[0067] In practical applications, the drain electrode 213 may be cylindrical with a diameter of 5 nm to 10 μm or an elliptical column with a major axis of 5 nm to 10 μm, a minor axis of 5 nm to 10 μm, and a major-to-minor axis ratio of 1.0 to 5.0.

[0068] The first metal layer 203 and the second metal layer 208 may be non-magnetic metal layers. The materials of the first metal layer 203 and the second metal layer 208 may include conductive metal materials or alloy materials. The first metal layer 203 and the second metal layer 208 are used to power the magnetic tunnel junction (including at least the first magnetic layer 204, the non-magnetic insulating layer or non-magnetic metal layer 205, and the second magnetic layer 206). The thickness of the first metal layer 203 and the second metal layer 208 along the z-axis direction may be 1nm-5nm. The area of ​​the first metal layer 203 and the second metal layer 208 is not less than the cross-sectional area of ​​the magnetic tunnel junction or the spin valve core structure.

[0069] The spin wave logic device provided by the above embodiment of the present invention adopts a magnetic tunnel junction or spin valve structure at the drain. Since the magnetic tunnel junction or spin valve has the function of not losing information after power failure, the spin wave logic device provided by the embodiment of the present invention is non-volatile, meets the demand for calling stored information at any time during the logic operation process, and is conducive to the design of storage and computing integrated devices and device architectures using storage and computing integrated devices. Moreover, since the magnetic tunnel junction or spin valve can be miniaturized to the nanoscale and compatible with semiconductor processes, the embodiment of the present invention is conducive to device miniaturization. In addition, when the source electrode adopts a magnetic material, since the magnetic moment arrangement direction of the magnetic material can be parallel or perpendicular to the magnetic metal film, or can be parallel or perpendicular to the magnetic metal film at any angle between the two, it can excite magnetic particles with different polarization directions, so that the spin wave logic device provided by the embodiment of the present invention is highly controllable.

[0070] Figure 6 A flowchart of a method for using a spin wave logic device provided by an embodiment of the present invention. The method can be Figure 5A or Figure 5B The spin wave logic device 200 shown in FIG. Figure 5B For example, combined with Figure 6 The method for using the spin wave logic device provided by the embodiment of the present invention is described in detail. Figure 6 As shown, the method of use may include the following steps.

[0071] In step 602, the spin wave logic device receives input information. In practical applications, the input information can be input into the spin wave logic device by applying a current to the source 211. In practical applications, the current density of the current applied at the source 211 can be in the range of 10 5 A / cm 2 to 10 8 A / cm 2 .

[0072] In step 604, the spin wave logic device converts the received electrical signal into a magnon signal. In an embodiment of the present invention, the source 211 can be a magnetic metal material or a heavy metal material, and the channel 212 can be a magnetic insulator material. When a current is applied to the source 211, spin accumulation will occur at the interface between the source 211 and the channel 212, so that magnons can be excited in the channel (212) through the interaction of the accumulated spin signals. Specifically, in the case where the source 211 is a magnetic material, the input electrical signal can be converted into a magnon signal through the spin anomalous Hall effect or the planar Hall effect of the magnetic material. In the case where the source 211 is a heavy metal material, the input electrical signal can be converted into a magnon signal through the spin Hall effect of the non-magnetic strong spin-orbit coupling material.

[0073] In the case where the source 211 is a magnetic metal material (or called a magnetic metal layer), after a current is applied to the magnetic metal layer (i.e., the source 211), due to the spin anomalous Hall effect or the planar Hall effect of the magnetic thin film material, spin accumulation (such as Figure 5B Because the number of spin accumulations generated on the upper and lower surfaces of the magnetic metal layer (i.e., the source 211) is different, a large number of magnons are excited in the magnetic insulator layer (i.e., the magnon channel 212) through the interaction between the spin accumulations that can pass through the upper and lower surfaces of the source 211.

[0074] In the case where the source 211 is a heavy metal material (or called a heavy metal layer), for example, the source 211 is a non-magnetic heavy metal thin film material with strong spin-orbit coupling. After the current is passed through the source 211, the current can be converted into spin accumulation (such as spin Hall effect, topological surface state, etc.) at the interface between the heavy metal layer (i.e., source 211) and the magnetic insulator layer (i.e., magnetic subchannel 212) through spin-orbit coupling (such as spin Hall effect, topological surface state, etc.). Figure 5B Furthermore, a large number of magnons are excited in the magnetic insulator layer (ie, the magnon channel 212 ) through the exchange and interaction of spin accumulation.

[0075] In step 606, the spin wave logic device realizes logic operations based on magnons by regulating the transmission of magnons. Specifically, the magnons generated in step 604 can propagate in the magnon channel 212 (e.g., Figure 5B ), and finally reaches the drain 213. During the propagation of the magnon in the magnon channel 212, the propagation characteristics of the magnon are regulated by the gate 214. Specifically, a voltage can be applied or an electric field can be introduced at the gate 214. Since the gate 214 can be a heavy metal material or a magnetic material, spins or magnons will be generated after the voltage is applied at the gate 214. The spins or magnons generated at the gate 214 interact with the magnons transmitted in the magnon channel 212, thereby realizing the regulation of the transmission pass rate of the magnons transmitted in the magnon channel 212, and realizing the function of enhancing or attenuating the propagation of the magnons. For example, the magnon-magnon interaction or the magnon-spin interaction can be used to enhance, keep almost unchanged or attenuate the magnons, thereby realizing the regulation of the transmission pass rate of the magnons transmitted in the magnon channel 212.

[0076] The process of magnons propagating and being regulated in the magnon channel 212 is equivalent to realizing the conduction and closing of the spin wave logic device channel. In practical applications, when the pass rate of magnons in the magnon channel 212 is high, it can be used to indicate a logical value of "1"; when the pass rate of magnons in the magnon channel 212 is low, it can be used to indicate a logical value of "0". It is understandable that the low pass rate of magnons in the magnon channel 212 can also be used to indicate "1", and the high pass rate of magnons in the magnon channel 212 can be used to indicate "1", and there is no limitation here. In practical applications, the current density applied to the gate 214 can range from 10 5 A / cm 2 to 10 8 A / cm 2 , or the voltage applied to the gate 214 can range from 0.5V to 12V.

[0077] In step 608, the spin wave logic device stores the magnon signal in the magnetic tunnel junction or spin valve. Specifically, the spin wave logic device stores the information in the magnetic tunnel junction or spin valve in a non-volatile manner by changing the magnetic moment direction of the magnetic layer of the magnetic tunnel junction or spin valve through the magnon torque effect. Figure 5B As shown, when the magnons are transferred from the magnon channel 212 to the bottom of the drain 213 through the control of the gate 214, since the drain 213 adopts a magnetic tunnel junction or spin valve structure, the magnons can pass through the first metal layer 203 and drive the magnetic moment of the first magnetic layer 204 to change direction through the magnon torque effect, so that the magnetic moment direction of the first magnetic layer 204 and the magnetic moment direction of the second magnetic layer 206 become parallel or antiparallel in the same direction. As mentioned above, when the magnetic moment direction of the first magnetic layer 204 and the magnetic moment direction of the second magnetic layer 206 are parallel in the same direction, the magnetoresistance is low, showing a low resistance state. When the magnetic moment direction of the first magnetic layer 204 and the magnetic moment direction of the second magnetic layer 206 are antiparallel, the magnetoresistance is high, showing a high resistance state. Therefore, by measuring the magnetoresistance, the "0" and "1" states of the magnon transistor can be detected. For example, the low resistance state can be used to indicate a logical "1", and the high resistance state can be used to indicate a logical "0". Furthermore, after power is turned off, the low resistance state and the high resistance state of the magnetic tunnel junction or the spin valve still exist, thereby enabling non-volatile storage of information in the drain 213 for continued use in subsequent operations.

[0078] In step 610, the spin wave logic device converts the magnon information into an electrical signal through the magnetoresistance effect, and obtains the logic operation result by reading the electrical signal output by the spin wave logic device. In practical applications, the first metal layer 203 and the second metal layer 208 can be used as upper and lower conductive electrodes. For example, the first metal layer 203 is used as the bottom electrode and the second metal layer 208 is used as the top electrode. By loading a detection current (for example, a direct current), the two states of "0" and "1" can be detected by magnetoresistance measurement, and the two logical states of the magnon transistor on and off can be read. Moreover, since the logical state can be stored non-volatilely in a magnetic tunnel junction or a spin valve (including a first magnetic layer 204, a non-magnetic insulating layer or a non-magnetic metal layer 205, and a second magnetic layer 206), it can be used for subsequent operations. In practical applications, the detection current density applied to the first metal layer 203 and the second metal layer 208 can be 10A / cm 2 to 10 4 A / cm 2 , the detection voltage range can be from 1mV to 1000mV.

[0079] from Figure 6 As can be seen from the illustrated embodiments, the drain of the spin wave logic device provided by the embodiment of the present invention utilizes tunneling magnetoresistance or giant magnetoresistance to detect magnon signals, which is beneficial to the miniaturization of the device and improves the information reading speed. Since the logic output information (for example, logic "1" and logic "0") of the spin wave logic device provided by the embodiment of the present invention is non-volatile and can be used for subsequent operations at any time, it is beneficial to reduce the power consumption of the device. In addition, the source of the spin wave logic device provided by the embodiment of the present invention can be made of magnetic material, and the spin anomalous Hall effect and the planar Hall effect are used to excite magnons, which can excite magnons with different polarization directions, and the device is highly controllable.

[0080] The spin wave logic device provided by the present application has a drain (i.e., the detection end) integrated with a magnetic tunnel junction or a spin valve structure, so that the magnon signal can be detected by using tunneling magnetoresistance or giant magnetoresistance. In addition, the magnetic moments of the upper and lower magnetic layers of the magnetic tunnel junction or spin valve are in-plane magnetic moment arrangements or perpendicular magnetic moment arrangements. Furthermore, the spin wave logic device provided by the embodiment of the present invention can integrate a magnetic metal or magnetic alloy film at the source (i.e., the magnon generating end) and use the spin anomalous Hall effect or the planar Hall effect to excite magnons. The magnetic moment arrangement of the magnetic metal or magnetic alloy film can be an in-plane magnetic moment arrangement, a perpendicular magnetic moment arrangement, or a non-perpendicular magnetic moment arrangement or other angle arrangement of the magnetic metal or magnetic alloy film. In the magnetic tunnel junction or spin valve structure integrated with the drain of the spin wave logic device, the magnetic moments of the first magnetic layer and the second magnetic layer can be both in-plane magnetic moment arrangements or both perpendicular magnetic moment arrangements. It is understandable that the above magnetic moment arrangements can be arbitrarily combined. In practical applications, a voltage can be applied to the source and the current can be detected at the drain. The magnitude of the current (or resistance) can be used to determine whether the device is on or off. For example, when the current flowing through the spin wave logic device is low, its resistance is high, indicating a high-resistance state, and the spin wave logic device can be determined to be off. When the current flowing through the spin wave logic device is high, its resistance is low, indicating a low-resistance state, and the spin wave logic device can be determined to be on.

[0081] In one possible implementation, spin wave logic devices can be used to form different circuits, such as Figure 7As shown, the circuit 700 may include at least one spin wave logic device 200 mentioned above, and the circuit 700 may be an integrated circuit or a chip, etc. The spin wave logic device 200 may be a magnetic transistor. The spin wave logic device 200 may be used in the circuit 700 to implement functions such as detection, rectification, amplification, switching, voltage regulation, and signal modulation. In practical applications, multiple spin wave logic devices 200 may be integrated to implement a processing circuit, such as a CPU or other circuit. The embodiment of the present application does not limit the device in which the circuit 700 is located, such as the circuit 700 may be a circuit in a processor. The processor may include a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), an artificial intelligence (AI) chip, a system on chip (SoC) or a complex programmable logic device (CPLD), a graphics processing unit (GPU), etc. Furthermore, in practical applications, the spin wave logic device 200 can be integrated with other devices to realize other functional circuits, which is not limited here.

[0082] It should be noted that the embodiments provided in this application are merely illustrative. Those skilled in the art will clearly understand that, for the convenience and brevity of description, in the above embodiments, the descriptions of each embodiment have their own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The features disclosed in the embodiments, claims, and drawings of the present invention may exist independently or in combination. The features described in the embodiment of the present invention in the form of hardware may be executed by software, and vice versa. This is not limited here.

Claims

1. A spin wave logic device, characterized in that: include: a channel and a drain and a source located above the channel; The source is used to generate a spin wave signal; The channel is used to transmit the spin wave signal to the drain, the material of the channel is a magnetic insulator material, and the channel is used to transmit magnons; The drain includes a magnetic tunnel junction or a spin valve structure, and is configured to exhibit different resistance states according to the spin wave signal, wherein the different resistance states are configured to indicate different logical values; The spin wave logic device further includes a gate, which is located between the source and the drain and includes a heavy metal material or a magnetic material. The gate is used to regulate the transmission of the spin wave signal.

2. The spin wave logic device according to claim 1, wherein: The magnetic tunnel junction includes a first magnetic layer, a non-magnetic insulating layer, and a second magnetic layer which are stacked.

3. The spin wave logic device according to claim 1, wherein: The spin valve structure includes a first magnetic layer, a non-magnetic metal layer and a second magnetic layer which are stacked.

4. The spin wave logic device according to claim 2, wherein: The drain further comprises: a first metal layer located between the channel and the first magnetic layer; a second metal layer, located on the second magnetic layer; Wherein, the first metal layer and the second metal layer are used for power supply.

5. The spin wave logic device according to claim 4, characterized in that The drain further comprises: The pinning layer is located between the second magnetic layer and the second metal layer and is used to fix the magnetic moment direction of the second magnetic layer.

6. The spin wave logic device according to any one of claims 1 to 5, characterized in that: The source electrode includes a magnetic metal material or a heavy metal material.

7. The spin wave logic device according to any one of claims 2 to 5, characterized in that: The materials of the first magnetic layer and the second magnetic layer include at least one of the following materials: iron (Fe), cobalt (Co), nickel (Ni), cobalt iron boron (CoFeB), nickel iron (NiFe), cobalt iron (CoFe), cobalt platinum (CoPt), cobalt nickel (CoNi), cobalt terbium (CoTb), cobalt gadolinium (CoGd), [Co / Tb] n 、[Co / Gd] n .

8. The spin wave logic device according to claim 2, wherein: The non-magnetic insulating layer includes at least one of the following materials: manganese oxide MgO, aluminum oxide Al2O3, aluminum nitride AlN, nickel oxide NiO, and aluminum manganese oxide MgAl2O4.

9. The spin wave logic device according to claim 3, characterized in that The non-magnetic metal layer includes at least one of the following materials: copper (Cu), aluminum (Al), and magnesium (Ag).

10. The spin wave logic device according to any one of claims 2 to 5, characterized in that: The thickness of the first magnetic layer and the second magnetic layer are both 1 nm to 10 nm.

11. The spin wave logic device according to claim 2, wherein: The thickness of the non-magnetic insulating layer is comprised between 0.7 nm and 10 nm.

12. The spin wave logic device according to claim 3, wherein: The thickness of the non-magnetic metal layer is comprised between 0.7 nm and 10 nm.

13. The spin wave logic device according to any one of claims 1 to 5, 8, 9, 11, and 12, characterized in that: The source electrode includes a ferromagnetic metal material, a ferrimagnetic metal material or an antiferromagnetic metal material.

14. The spin wave logic device according to any one of claims 1 to 5, 8, 9, 11, and 12, characterized in that: The source electrode includes at least one of the following materials: cobalt Co, nickel Ni, cobalt iron boron CoFeB, nickel iron NiFe, cobalt iron CoFe, cobalt platinum CoPt, cobalt nickel CoNi, [Co / Tb] n 、[Co / Gd] n , iridium manganese IrMn, platinum manganese PtMn, iron manganese FeMn.

15. A circuit, characterized in that: Comprising one or more spin wave logic devices according to any one of claims 1 to 14.

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