Spin-orbit torque magnetic tunnel junction and majority gate spin logic devices and cascades thereof

Abstract

Disclosed are a spin-orbit torque magnetic tunnel junction and a majority gate spin logic device and a cascade thereof, in the magnetic tunnel junction, comprising, from top to bottom, an electrode layer, an artificial antiferromagnetic reference layer, an insulating tunneling layer, a magnetized free layer, and an abnormal spin-orbit torque layer, wherein the artificial antiferromagnetic reference layer comprises, from top to bottom, a first ferromagnetic layer, a non-magnetic spacer layer, and a second ferromagnetic layer, the first ferromagnetic layer has a fixed direction of perpendicular magnetization; the electrode layer in contact with the first ferromagnetic layer has an in-plane polarization to adjust the magnetization direction of the second ferromagnetic layer, the magnetic free layer has a variable direction of perpendicular magnetization; the abnormal spin-orbit torque layer in contact with the magnetic free layer has an in-plane magnetization direction to generate an abnormal spin Hall effect to make the magnetic free layer magnetization flip, thereby changing the spin-orbit torque magnetic tunnel junction resistance state and realizing a logic function.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of magnetic tunnel junction technology based on electric field regulation of RKKY and spin-orbit torque, and particularly relates to a spin-orbit torque magnetic tunnel junction and majority gate spin logic device and cascades thereof. BACKGROUND

[0002] Traditional logic devices have encountered a series of challenges in the development process, mainly focusing on energy consumption, preparation complexity, and atomic scale physical limits. These problems restrict the performance of traditional semiconductor devices in meeting the needs of artificial intelligence. However, with the deepening of scientific research and the progress of technology, logic devices based on electron spin provide a new path to solve these challenges.

[0003] Magnetic tunnel junction (MTJ) is the core part of spin logic devices, and currently the free layer magnetization is flipped through an external magnetic field, STT effect, SOT effect, and the reference layer is flipped through SOT effect to achieve logic. Deterministic flipping through an external magnetic field is not conducive to the production of high-density large-capacity memory, and the performance and power consumption will also be affected. Although the power consumption of logic devices based on STT effect has been greatly reduced compared to CMOS devices, it is still much higher than that of logic devices based on SOT effect. However, ordinary SOT effect logic devices cannot achieve deterministic flipping of the magnetic free layer, which is the main reason for the limitation of the development of SOT effect logic devices.

[0004] The information disclosed in the background section is only used to enhance the understanding of the background of the present application, and therefore can contain information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0005] In view of the deficiencies or shortcomings of the prior art, a spin-orbit torque magnetic tunnel junction and majority gate spin logic device and cascades thereof are provided, which adopts anomalous spin Hall effect to realize flipping of the magnetic free layer, uses ferroelectric polarization electric field to regulate RKKY effect to flip the magnetization direction of the reference layer, and proposes a logic device based on MTJ that can realize Boolean logic, effectively solving the problems of energy consumption and inability to flip deterministically.

[0006] The purpose of the present application is achieved by the following technical solutions.

[0007] A spin-orbit magnetic tunnel junction includes, from top to bottom, an electrode layer, an artificial antiferromagnetic reference layer, an insulating tunneling layer, a magnetized free layer, and an anomalous spin-orbit layer. The artificial antiferromagnetic reference layer comprises, from top to bottom, a first ferromagnetic layer, a non-magnetic spacer layer, and a second ferromagnetic layer. The first ferromagnetic layer has a fixed-direction vertical magnetization. The electrode layer in contact with the first ferromagnetic layer has in-plane polarization to adjust the magnetization direction of the second ferromagnetic layer. The magnetic free layer has a variable-direction vertical magnetization. This can be achieved by applying magnetization to the electrode layer... Applying voltage modulates the polarization direction to the vertical direction, generating charge transfer and a ferroelectric polarization field in the vertical direction. This causes the artificial antiferromagnetic reference layer to flip between an antiferromagnetic coupling state and a ferromagnetic coupling state, thereby changing the magnetization direction of the second ferromagnetic layer in the artificial antiferromagnetic reference layer and realizing the logic function. The anomalous spin orbital moment layer of the contact valve with the magnetic free layer has an in-plane magnetization direction to generate an anomalous spin Hall effect, causing the magnetization of the magnetic free layer to flip, thereby changing the resistance state of the spin orbital moment magnetic tunnel junction and realizing the logic function.

[0008] In the aforementioned spin-orbit magnetic tunnel junction, by applying an in-plane current to the anomalous spin-orbit layer, an out-of-plane spin current is generated based on the anomalous spin Hall effect. After the spin current flows into the magnetic free layer, it flips the magnetization direction of the magnetic free layer to be in the same direction as the spin polarization direction, thereby realizing the switching of the spin-orbit magnetic tunnel junction between the high-resistivity state and the low-resistivity state.

[0009] In the aforementioned spin-orbit magnetic tunnel junction, the anomalous spin-orbit layer consists of magnetic point groups of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 ... , , and The magnetic materials consist of Mn2ScSbO6, Cr2S3, Fe4O5, GaFeO3, ScFeO3, FeF3, and NdFeO3.

[0010] In the aforementioned spin-orbit magnetic tunnel junction, the electrode layer is formed of insulating or semiconductor ferroelectric materials, including BaTiO3, BiFeO3, PbTiO3, SrTiO3, and HZO.

[0011] In the aforementioned spin-orbit-moment magnetic tunnel junction, the magnetized free layer includes magnetic materials that provide TMR and vertical anisotropy, and the vertical anisotropy magnetic materials include CoFe, CoCrPt, and CoFeB.

[0012] In the aforementioned spin-orbit magnetic tunnel junction, the first and second ferromagnetic layers are magnetic materials with perpendicular anisotropy and interlayer coupling strength, including Ni, CoCrPt, and (Co / Pd). m Or (Co / Pt) nwherein m, n refer to the number of repetitions of the multilayer stack; the non-magnetic spacer layer comprises Au, Cu, Ag, Re, Ru, Os, Rh.

[0013] A majority gate spin logic device comprises four spin-orbit torque magnetic tunnel junctions, the four magnetic tunnel junctions are sequentially denoted as input MTJ1, input MTJ2, control MTJ and output MTJ, the free layer magnetization direction of the input MTJ1, the free layer magnetization direction of the input MTJ2, the free magnetization direction of the control MTJ are determined by the direction and size of the in-plane current applied to the anomalous spin-orbit torque layer, the free layer magnetization direction of the output MTJ is determined by the free layer magnetization direction of the input MTJ1, the free layer magnetization direction of the input MTJ2 and the free magnetization direction of the control MTJ; the output MTJ presents a resistance state determined by the free layer magnetization direction and the magnetization direction of the insulating tunnel layer; after the in-plane current is applied to the anomalous spin-orbit torque layer, the domain wall moves from the positions of the input MTJ1, the input MTJ2 and the control MTJ to the output MTJ4; the free layer magnetization direction is determined by the movement of the domain wall; when the control MTJ is in a high resistance state, the output MTJ and the input MTJ1 and the input MTJ2 realize "or" logic, at this time the first ferromagnetic layer and the second ferromagnetic layer of the control output MTJ flip from the antiferromagnetic coupling state to the ferromagnetic coupling state, and the output MTJ and the input MTJ1 and the input MTJ2 realize "nand" logic; when the control MTJ is in a low resistance state, the output MTJ and the output MTJ1 and the output MTJ2 realize "and" logic, at this time the first ferromagnetic layer and the second ferromagnetic layer of the control output MTJ flip from the antiferromagnetic coupling state to the ferromagnetic coupling state, and the output MTJ and the input MTJ1 and the input MTJ2 realize "nand" logic.

[0014] The majority gate spin logic device is a cross-shaped structure, and the cross-shaped structure has four branches, two of which are input branches, one is a control branch, and one is an output branch; the input MTJ1 and the input MTJ2 are respectively located at the endpoints of the two input branches, the control MTJ is located at the endpoint of the control branch, and the output MTJ is located at the endpoint of the output branch.

[0015] A kind of cascade majority gate spin logic device includes four described majority gate spin logic device, respectively, majority gate spin logic device 1, majority gate spin logic device 2, majority gate spin logic device 3, majority gate spin logic device 4, the output MTJ free layer of majority gate spin logic device 1 is cascaded with the input MTJ1 free layer of majority gate spin logic device 3 by copper wire, the output MTJ free layer of majority gate spin logic device 2 is cascaded with the input MTJ2 free layer of majority gate spin logic device 3 by copper wire, majority gate spin logic device 1, majority gate spin logic device 2, majority gate spin logic device 3 jointly constitute "Diff" output group, majority gate spin logic device 4 as "Borrow" output group;

[0016] Parallel to the film surface input current I1 is injected to the input MTJ1 of majority gate spin logic device 1 to the abnormal spin orbit moment layer;Parallel to the film surface input current I2 is injected to the input MTJ2 of majority gate spin logic device 1 to the abnormal spin orbit moment layer;Parallel to the film surface control current J1 is injected to the abnormal spin orbit moment layer of the control MTJ of majority gate spin logic device 1 to make it in low resistance state, and majority gate spin logic device 1 realizes "and" logic;

[0017] Parallel to the film surface input current I3 is injected to the input MTJ1 of majority gate spin logic device 2 to the abnormal spin orbit moment layer, and input current I3 is same in size and opposite in direction with input current I1;Parallel to the film surface input current I4 is injected to the input MTJ2 of majority gate spin logic device 2 to the abnormal spin orbit moment layer, and input current I4 is same in size and opposite in direction with input current I2;Parallel to the film surface control current J2 is injected to the abnormal spin orbit moment layer of the control MTJ of majority gate spin logic device 2 to make it in low resistance state, and control current J1 and control current J2 are same in size and same in direction, so that majority gate spin logic device 2 realizes "and" logic;

[0018] Parallel to the film surface control current J3 is injected to the abnormal orbit moment layer of the control MTJ of majority gate spin logic device 3 to make it in high resistance state, wherein, control current J3 and control current J1, control current J2 are equal in size and opposite in direction, and cascade majority gate spin logic device "exclusive or" logic;

[0019] The input current I5 parallel to the film surface is injected to the abnormal spin orbit moment layer of the input MTJ1 of the majority gate spin logic device 4, the input current I5 is same in size and opposite in direction to the input current I1; the input current I6 parallel to the film surface is injected to the abnormal spin orbit moment layer of the input MTJ2 of the majority gate spin logic device 4, the input current I6 is same in size and opposite in direction to the input current I2; the control current J4 parallel to the film surface is injected to the abnormal spin orbit moment layer of the control MTJ of the majority gate spin logic device 1 to make it in the low resistance state, the control current J4 is same in size and same in direction to the control current J1 and the control current J2, and the majority gate spin logic device 4 realizes the AND logic;

[0020] The output MTJ of the majority gate spin logic device 3 is as a Diff output end for realizing the half subtractor logic, the output MTJ of the majority gate spin logic device 4 is as a Borrow output end for realizing the half subtractor logic, the input MTJ1 of the majority gate spin logic device 1, the input MTJ1 of the majority gate spin logic device 2 and the input MTJ1 of the majority gate spin logic device 4 are collectively as the minuend input end for realizing the half subtractor logic, and the input MTJ2 of the majority gate spin logic device 1, the input MTJ2 of the majority gate spin logic device 2 and the input MTJ2 of the majority gate spin logic device 4 are collectively as the subtrahend input end for realizing the half subtractor logic.

[0021] The cascaded majority gate spin logic device is a symmetrical structure for realizing the one-bit half subtractor function.

[0022] Compared with the prior art, the beneficial effects brought by the application are:

[0023] The application refers to a spin orbit torque magnetic tunnel junction with reference layer magnetization reversible spin, which adopts an elliptical structure, increases the shape anisotropy in the free layer, effectively improves the flipping speed, and reduces the power consumption. Since the data writing of the MTJ is realized by using the abnormal spin Hall effect, compared with the STT assisted flipping, the current density through the memory is effectively reduced, the possibility of damage of the device due to breakdown is greatly avoided, the device reliability is effectively improved, and the power consumption is reduced. The majority gate spin logic device supports the device cascade to form a logic circuit, and performs more complex logic functions such as half subtracter. The majority gate spin logic device based on the spin orbit torque can realize the directional flipping of the free layer in the MTJ without an external magnetic field, is conducive to the manufacture of low-cost, high-density and large-capacity logic devices, improves the performance, and has the functions of non-volatile storage and repeated programming. The application adjusts the polarization direction of the electrode layer by applying a voltage, controls the polarization direction to the vertical direction, generates a larger charge transfer and ferroelectric polarization electric field in the vertical direction, changes the coupling state of the artificial antiferromagnetic reference layer, and then realizes the magnetization flipping of the reference layer, effectively improves the device reliability, and reduces the power consumption. As an array of majority gate spin devices, the manufacturing process of the MTJ is compatible with the CMOS process, and is convenient for integration. Most importantly, the application can realize the functions of storage and operation in four MTJ units, thereby reducing the demand for multiple memories, reducing the area of the corresponding body and equipment, reducing the complexity of the system, improving the cost-effectiveness, and prolonging the battery life. In addition, the device design is less affected by accidental errors, and when the parameters deviate to a certain extent, the device can still work normally.

[0024] The description is only a summary of the technical scheme of the application, in order to make the technical means of the application more clear and understandable, to the extent that the person skilled in the art can implement according to the content of the description, and in order to make the application and other purposes, features and advantages more obvious and easy to understand, the following specific embodiments of the application are exemplified. BRIEF DESCRIPTION OF DRAWINGS

[0025] Various other advantages and benefits of the present application will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not meant to limit the present application. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained from these drawings without creative labor for those of ordinary skill in the art. Moreover, the same reference numerals are used to represent the same components throughout the drawings.

[0026] In the drawings:

[0027] Figure 1A structure diagram of the spin-orbit torque magnetic tunnel junction with magnetization reversible reference layer provided by the embodiment of the present application is provided;

[0028] Figure 2 A principle diagram of the magnetic tunnel junction free layer flip for injecting current to the abnormal orbit moment layer is provided;

[0029] Figure 3 A principle diagram of the magnetic tunnel junction reference layer flip for applying voltage to the electrode layer is provided;

[0030] Figure 4 A top view of the majority gate spin logic device based on the spin-orbit torque magnetic tunnel junction with magnetization reversible reference layer provided by the embodiment of the present application is provided;

[0031] Figure 5 A side structure diagram of the majority gate spin logic device based on the spin-orbit torque magnetic tunnel junction with magnetization reversible reference layer provided by the embodiment of the present application is provided;

[0032] Figure 6 A logic circuit diagram of the cascade majority gate spin logic device when implementing the half-subtractor logic is provided.

[0033] The present application will be further explained in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0034] The specific embodiments of the present application will be described below in conjunction with the accompanying drawings. Although the specific embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0035] It should be noted that certain terms are used throughout the specification and claims which have particular meanings. Those skilled in the art will understand that the same component can be referred to by different names. The specification and claims do not distinguish components based on the difference in names, but rather on the difference in functions. As mentioned throughout the specification and claims, "comprising" or "including" is an open term, which should be interpreted as "including but not limited to". The subsequent description in the specification is a preferred embodiment for implementing the present application, which is for the purpose of illustrating the general principles of the specification, and is not intended to limit the scope of the present application. The scope of protection of the present application is defined by the appended claims.

[0036] In order to facilitate the understanding of the embodiments of the present application, the following will be further explained and described with several specific embodiments as examples in conjunction with the accompanying drawings, and each drawing does not constitute a limitation to the embodiments of the present application.

[0037] For better understanding, as shown in Figures 1 to 6 A spin-orbit torque magnetic tunnel junction includes, from top to bottom, an electrode layer, an artificial antiferromagnetic reference layer, an insulating tunneling layer, a magnetized free layer, and an anomalous spin-orbit torque layer, wherein the artificial antiferromagnetic reference layer includes, from top to bottom, a first ferromagnetic layer, a non-magnetic spacer layer, and a second ferromagnetic layer, the first ferromagnetic layer has a fixed direction of perpendicular magnetization; the electrode layer in contact with the first ferromagnetic layer has an in-plane polarization to adjust the magnetization direction of the second ferromagnetic layer, the magnetized free layer has a variable direction of perpendicular magnetization, by applying a voltage to the electrode layer, the polarization direction is adjusted to the vertical direction, to generate a charge transfer and a ferroelectric polarization electric field in the vertical direction, to flip the artificial antiferromagnetic reference layer between an antiferromagnetic coupling state and a ferromagnetic coupling state, thereby changing the magnetization direction of the second ferromagnetic layer in the artificial antiferromagnetic reference layer, to realize a logic function; the anomalous spin-orbit torque layer in contact with the magnetized free layer has an in-plane magnetization direction to generate an anomalous spin Hall effect to flip the magnetization of the magnetized free layer, thereby changing the resistance state of the spin-orbit torque magnetic tunnel junction, to realize a logic function.

[0038] In a preferred embodiment of the spin-orbit torque magnetic tunnel junction, by applying an in-plane current to the anomalous spin-orbit torque layer, an out-of-plane spin current is generated according to the anomalous spin Hall effect, which flows into the magnetized free layer and flips the magnetization direction of the magnetized free layer to the same direction as the spin polarization direction, to switch the spin-orbit torque magnetic tunnel junction between a high resistance state and a low resistance state.

[0039] In a preferred embodiment of the spin-orbit torque magnetic tunnel junction, the anomalous spin-orbit torque layer is composed of a magnetic material with a magnetic point group of 1, , , and The magnetic material includes Mn2ScSbO6, Cr2S3, Fe4O5, GaFeO3, ScFeO3, FeF3, NdFeO3.

[0040] In a preferred embodiment of the spin-orbit torque magnetic tunnel junction, the electrode layer is formed of an insulating or semiconductive ferroelectric material, the semiconductive ferroelectric material includes BaTiO3, BiFeO3, PbTiO3, SrTiO3, HZO.

[0041] In a preferred embodiment of the spin-orbit torque magnetic tunnel junction, the magnetized free layer includes a magnetic material that provides TMR and perpendicular anisotropy, the magnetic material with perpendicular anisotropy includes CoFe, CoCrPt, CoFeB.

[0042] In the preferred embodiment of the spin-orbit torque magnetic tunnel junction, the first ferromagnetic layer and the second ferromagnetic layer are perpendicular anisotropic magnetic materials with interlayer coupling strength, which include Ni, CoCrPt, (Co / Pd) m or (Co / Pt) n wherein m, n refer to the number of repetitions of the multilayer stack; the non-magnetic spacer layer includes Au, Cu, Ag, Re, Ru, Os, Rh.

[0043] A majority gate spin logic device includes four spin-orbit torque magnetic tunnel junctions, which are sequentially denoted as input MTJ1, input MTJ2, control MTJ and output MTJ. The free layer magnetization direction of the input MTJ1, the free layer magnetization direction of the input MTJ2, and the free magnetization direction of the control MTJ are determined by the direction and magnitude of the in-plane current applied to the anomalous spin-orbit torque layer. The free layer magnetization direction of the output MTJ is determined by the free layer magnetization direction of the input MTJ1, the free layer magnetization direction of the input MTJ2, and the free magnetization direction of the control MTJ. The resistance state of the output MTJ is determined by the free layer magnetization direction and the magnetization direction of the insulating tunneling layer. After the in-plane current is applied to the anomalous spin-orbit torque layer, the domain wall moves from the positions of the input MTJ1, the input MTJ2 and the control MTJ to the output MTJ4. The free layer magnetization direction is determined by the movement of the domain wall. When the control MTJ is in a high resistance state, the output MTJ and the input MTJ1 and the input MTJ2 implement an OR logic. At this time, the first ferromagnetic layer and the second ferromagnetic layer of the output MTJ are flipped from the antiferromagnetic coupling state to the ferromagnetic coupling state. The output MTJ and the input MTJ1 and the input MTJ2 implement an OR NOT logic. When the control MTJ is in a low resistance state, the output MTJ and the output MTJ1 and the output MTJ2 implement an AND logic. At this time, the first ferromagnetic layer and the second ferromagnetic layer of the output MTJ are flipped from the antiferromagnetic coupling state to the ferromagnetic coupling state. The output MTJ and the input MTJ1 and the input MTJ2 implement an AND NOT logic.

[0044] In the preferred embodiment of the majority gate spin logic device, it is a cross-shaped structure, which has four branches. Two branches are input branches, one branch is a control branch, and one branch is an output branch. The input MTJ1 and the input MTJ2 are respectively located at the end points of the two input branches. The control MTJ is located at the end point of the control branch. The output MTJ is located at the end point of the output branch.

[0045] A kind of cascade majority gate spin logic device includes four described majority gate spin logic device, respectively, majority gate spin logic device 1, majority gate spin logic device 2, majority gate spin logic device 3, majority gate spin logic device 4, the output MTJ free layer of majority gate spin logic device 1 is cascaded with the input MTJ1 free layer of majority gate spin logic device 3 by copper wire, the output MTJ free layer of majority gate spin logic device 2 is cascaded with the input MTJ2 free layer of majority gate spin logic device 3 by copper wire, majority gate spin logic device 1, majority gate spin logic device 2, majority gate spin logic device 3 jointly constitute "Diff" output group, majority gate spin logic device as "Borrow" output group;

[0046] Parallel to the film surface input current I1 is injected to the input MTJ1 of majority gate spin logic device 1 to the abnormal spin orbit moment layer;Parallel to the film surface input current I2 is injected to the input MTJ2 of majority gate spin logic device 1 to the abnormal spin orbit moment layer;Parallel to the film surface control current J1 is injected to the abnormal spin orbit moment layer of the control MTJ of majority gate spin logic device 1 to make it in low resistance state, and majority gate spin logic device 1 realizes "and" logic;

[0047] Parallel to the film surface input current I3 is injected to the input MTJ1 of majority gate spin logic device 2 to the abnormal spin orbit moment layer, and input current I3 is same in size and opposite in direction with input current I1;Parallel to the film surface input current I4 is injected to the input MTJ2 of majority gate spin logic device 2 to the abnormal spin orbit moment layer, and input current I4 is same in size and opposite in direction with input current I2;Parallel to the film surface control current J2 is injected to the abnormal spin orbit moment layer of the control MTJ of majority gate spin logic device 2 to make it in low resistance state, and control current J1 is same in size and same in direction with control current J2, so that majority gate spin logic device 2 realizes "and" logic;

[0048] Parallel to the film surface control current J3 is injected to the abnormal orbit moment layer of the control MTJ of majority gate spin logic device 3 to make it in high resistance state, wherein, control current J3 is equal in size and opposite in direction with control current J1, control current J2, and cascade majority gate spin logic device "exclusive or" logic;

[0049] An input current I5 parallel to the film plane is injected to the abnormal spin orbit torque layer of the input MTJ1 of the majority gate spin logic device 4, the input current I5 is the same as the input current I1 in size and opposite in direction; an input current I6 parallel to the film plane is injected to the abnormal spin orbit torque layer of the input MTJ2 of the majority gate spin logic device 4, the input current I6 is the same as the input current I2 in size and opposite in direction; a control current J4 parallel to the film plane is injected to the abnormal spin orbit torque layer of the control MTJ of the majority gate spin logic device 1 to make it in a low resistance state, the control current J4 is the same as the control current J1 and the control current J2 in size and same in direction, and the majority gate spin logic device 4 realizes the "and" logic;

[0050] The output MTJ of the majority gate spin logic device 3 is used as a "Diff" output terminal for realizing the half subtracter logic, the output MTJ of the majority gate spin logic device 4 is used as a "Borrow" output terminal for realizing the half subtracter logic, the input MTJ1 of the majority gate spin logic device 1, the input MTJ1 of the majority gate spin logic device 2 and the input MTJ1 of the majority gate spin logic device 4 are used as the minuend input terminals for realizing the half subtracter logic, and the input MTJ2 of the majority gate spin logic device 1, the input MTJ2 of the majority gate spin logic device 2 and the input MTJ2 of the majority gate spin logic device 4 are used as the subtrahend input terminals for realizing the half subtracter logic.

[0051] In the preferred embodiment of the cascade majority gate spin logic device, a symmetric structure is used to realize the one-bit half subtracter function.

[0052] In one embodiment, the spin orbit torque magnetic tunnel junction adopts an elliptical structure, and the magnetization of the reference layer can be flipped.

[0053] In one embodiment, Figure 1 The spin orbit torque magnetic tunnel junction provided by the application comprises, from top to bottom, an electrode layer 70, an artificial antiferromagnetic reference layer 60, 50, 40, an insulating tunnel layer 30, a magnetized free layer 20 and an abnormal spin orbit torque layer 10. The artificial antiferromagnetic reference layer is composed of a first ferromagnetic layer 60, a non-magnetic spacer layer 50 and a second ferromagnetic layer 40. The magnetic free layer has a direction-variable perpendicular magnetization. The first ferromagnetic layer 60 of the artificial antiferromagnetic reference layer has a direction-fixed perpendicular magnetization.

[0054] Figure 2The principle diagram for injecting current to the anomalous orbital moment layer to realize the flipping of the free layer of the magnetic tunnel junction is shown in FIG. 1. The working principle is as follows: the first ferromagnetic layer 60 and the second ferromagnetic layer 40 are in an anti-ferromagnetic coupling state, an external magnetic field is applied to make the magnetization state of the first ferromagnetic layer 60 be in the Z direction, and the magnetization state of the second ferromagnetic layer 40 be in the -Z direction, an external magnetic field is applied to make the magnetization direction of the magnetic free layer 20 be in the -Z direction, the magnetization direction of the magnetic free layer 20 and the magnetization direction of the second ferromagnetic layer 40 are in an anti-parallel arrangement, a bias voltage is applied between one of the third electrode 83 and the fourth electrode 84 and the second electrode 82, based on the basic principle of the spin valve or the magnetic tunnel junction, a low resistance is measured to be in a low resistance state (0 state), and the magnetization direction of the spin orbital moment layer 10 is in the X direction. An in-plane current J flowing through the anomalous spin orbital moment layer 10 is applied between the third electrode 83 and the fourth electrode 84. When the charge current J and the magnetization direction of the magnetic moment M are in the same direction, according to the anomalous spin Hall effect, a spin-polarized current is generated, which is perpendicular to the film surface , the spin-polarized current flows from the anomalous spin orbital moment layer 10 to the magnetic free layer 20, the magnetization direction of the magnetic free layer 20 is flipped to the Z direction, the magnetization direction of the magnetic free layer 20 and the magnetization direction of the magnetic fixed layer 40 are in a parallel arrangement, a bias voltage is applied between one of the third electrode 83 and the fourth electrode 84 and the second electrode 82, based on the basic principle of the spin valve or the magnetic tunnel junction, a high resistance is measured to be in a high resistance state (1 state).

[0055] Figure 3 The principle diagram for applying a voltage to the electrode layer to realize the flipping of the reference layer of the magnetic tunnel junction is shown in FIG. 2. The working principle is as follows: the initial electrode layer 70 is in an in-plane polarization state, at this time, the coupling coefficient of the first ferromagnetic layer 60 and the second ferromagnetic layer 40 is negative, and the first ferromagnetic layer 60 and the second ferromagnetic layer 40 are in an anti-ferromagnetic coupling state, the magnetization state of the first ferromagnetic layer 60 is fixed in the Z direction, the magnetization state of the second ferromagnetic layer 40 is in the -Z direction, an external magnetic field is applied to make the magnetization direction of the magnetic free layer 20 be in the -Z direction, the magnetization direction of the magnetic free layer 20 and the magnetization direction of the second ferromagnetic layer 40 are in an anti-parallel arrangement, a bias voltage is applied between one of the third electrode 83 and the fourth electrode 84 and the second electrode 82, based on the basic principle of the spin valve or the magnetic tunnel junction, a high resistance is measured to be in a high resistance state (1 state), a voltage is applied to the electrode layer 70 through the first electrode 81, the polarization direction of the electrode layer single layer is adjusted to the vertical direction, so as to generate a large charge transfer and ferroelectric polarization electric field in the vertical direction, so that the first ferromagnetic layer 60 and the second ferromagnetic layer 40 are flipped from the anti-ferromagnetic coupling state to the ferromagnetic coupling state, at this time, the magnetization state of the second ferromagnetic layer 40 is changed to the -Z direction, the magnetization direction of the magnetic free layer 20 and the magnetization direction of the second ferromagnetic layer 40 are in a parallel arrangement, a bias voltage is applied between one of the third electrode 83 and the fourth electrode 84 and the second electrode 82, based on the basic principle of the spin valve or the magnetic tunnel junction, a low resistance is measured to be in a low resistance state (0 state).

[0056] Figure 4 A top view of a majority gate spin logic device based on a spin orbit torque magnetic tunnel junction with a reference layer magnetization that can be flipped, Figure 5 A side view of a majority gate spin logic device based on a spin orbit torque magnetic tunnel junction with a reference layer magnetization that can be flipped. The majority gate spin logic device includes four spin orbit torque magnetic tunnel junctions that can be directionally flipped, and the four magnetic tunnel junctions are sequentially labeled as input MTJ1, input MTJ2, control MTJ, and output MTJ. The input MTJ1 includes electrode layers 71, an artificial anti-ferromagnetic reference layer 61, 51, 41, an insulating tunneling layer 31, a magnetization free layer 21, and an anomalous spin orbit torque layer 11 arranged in sequence, and the artificial anti-ferromagnetic reference layer is composed of a first ferromagnetic layer 61, a non-magnetic spacer layer 51, and a second ferromagnetic layer 41. The input MTJ2 includes electrode layers 72, an artificial anti-ferromagnetic reference layer 62, 52, 42, an insulating tunneling layer 32, a magnetization free layer 21, and an anomalous spin orbit torque layer 12 arranged in sequence, and the artificial anti-ferromagnetic reference layer is composed of a first ferromagnetic layer 62, a non-magnetic spacer layer 52, and a second ferromagnetic layer 42. The control MTJ includes electrode layers 73, an artificial anti-ferromagnetic reference layer 63, 53, 43, an insulating tunneling layer 33, a magnetization free layer 21, and an anomalous spin orbit torque layer 13 arranged in sequence, and the artificial anti-ferromagnetic reference layer is composed of a first ferromagnetic layer 63, a non-magnetic spacer layer 53, and a second ferromagnetic layer 43. The output MTJ includes electrode layers 74, an artificial anti-ferromagnetic reference layer 64, 54, 44, an insulating tunneling layer 34, a magnetization free layer 21, and an anomalous spin orbit torque layer 14 arranged in sequence, and the artificial anti-ferromagnetic reference layer is composed of a first ferromagnetic layer 64, a non-magnetic spacer layer 54, and a second ferromagnetic layer 44. The input MTJ2, the control MTJ, and the output MTJ are all spin orbit torque magnetic tunnel junctions with a reference layer magnetization that can be flipped.

[0057] The device structure is a cross-shaped four branches, two of which are input branches, one is a control branch, and one is an output branch. The input MTJ1 and the input MTJ2 are respectively located at the end points of the two input branches, the control MTJ is located at the end point of the control branch, and the output MTJ is located at the end point of the output branch.

[0058] The principle of implementing logic by the majority gate spin device based on the spin orbit torque magnetic tunnel junction with a reference layer magnetization that can be flipped is as follows:

[0059] The initial polarization states of the electrode layer 71 in the input MTJ1, the electrode layer 72 in the input MTJ2, the electrode layer 73 in the control MTJ, and the electrode layer 74 in the output MTJ are uniformly determined as in-plane polarization.

[0060] The initial coupling states between the first ferromagnetic layer 41 and the second ferromagnetic layer 61 in the input MTJ 1, the first ferromagnetic layer 42 and the second feromagnetic layer 62 in the input MTJ 2, the first ferromagnetic layer 43 and the second ferromagnetic layer 63 in the control MTJ, and the first ferromagnetic layer 44 and the second ferromagnetic layer 64 in the output MTJ are uniformly determined as anti-ferromagnetic coupling.

[0061] The initial magnetization states of the second ferromagnetic layer 41 in the input MTJ 1, the second ferromagnetic layer 42 in the input MTJ 2, the second ferromagnetic layer 43 in the control MTJ, and the second ferromagnetic layer 44 in the output MTJ are uniformly determined as the +z direction, and the magnetization states of the first ferromagnetic layer 61 in the input MTJ 1, the first ferromagnetic layer 62 in the input MTJ 2, the first ferromagnetic layer 63 in the control MTJ, and the first ferromagnetic layer 64 in the output MTJ are fixed as the -z direction.

[0062] The current parallel to the film surface is injected into the abnormal spin orbit torque layer 13 of the control MTJ, so that the magnetization direction of the magnetization free layer 23 of the control MTJ is the z direction. At this time, the second ferromagnetic layer 43 and the magnetization direction of the magnetization free layer 23 are in parallel arrangement, which shows a low resistance state (0 state) with low resistance; the current parallel to the film surface is injected into the abnormal spin orbit torque layers 11 and 12 of the input MTJ, so that the magnetization directions of the magnetization free layers 21 and 22 are changed. At this time, through the domain wall motion, according to the majority logic, the magnetization state of the magnetization free layer 24 of the output MTJ is determined by the magnetization free layer 21 of the input MTJ 1, the magnetization free layer 22 of the input MTJ 2, and the magnetization free layer 23 of the control MTJ, that is, the "and" logic can be realized. At this time, the voltage is applied to the electrode layer 74 of the output MTJ through the external signal source, so that the polarization direction of the electrode layer 74 is adjusted to the vertical direction, thereby generating a larger charge transfer and ferroelectric polarization electric field in the vertical direction, so that the coupling state between the first ferromagnetic layer 64 and the second ferromagnetic layer 44 changes from the anti-ferromagnetic coupling state to the ferromagnetic coupling state. Since the magnetization direction of the first ferromagnetic layer is fixed as the z direction, the magnetization direction of the second ferromagnetic layer will be flipped from the -z direction to the z direction, that is, the logic output opposite to the "and" logic can be realized, which is the "NAND" logic.

[0063] The current parallel to the film surface is injected into the control MTJ's abnormal spin orbit torque layer 13, so that the magnetization free layer 20 of the control MTJ is magnetized in the -z direction, at this time, the second ferromagnetic layer 43 and the magnetization direction of the magnetization free layer 23 are anti-parallel arranged, which shows the high resistance state (1 state) with high resistance; The current parallel to the film surface is injected into the input MTJ's abnormal spin orbit torque layer 11, 12, the magnetization direction of the magnetization free layer 21, 22 is changed, at this time, through the domain wall motion, according to the majority logic, the magnetization state of the output MTJ magnetization free layer 24 is determined by the magnetization free layer 21 of the input MTJ1, the magnetization free layer 22 of the input MTJ2, and the magnetization free layer 23 of the control MTJ, that is, the "or" logic can be realized. At this time, the voltage is applied to the electrode layer 74 of the output MTJ through the external signal source, so that the polarization direction of the electrode layer 74 is adjusted to the vertical direction, so that a larger charge transfer and ferroelectric polarization electric field are generated in the vertical direction, and the coupling state between the first ferromagnetic layer 64 and the second ferromagnetic layer 44 is changed from the anti-ferromagnetic coupling state to the ferromagnetic coupling state, and since the magnetization direction of the first ferromagnetic layer is fixed in the z direction, the magnetization direction of the second ferromagnetic layer will be flipped from the -z direction to the z direction, that is, the logic output opposite to the "and" logic is realized, which is "or not" logic.

[0064] Figure 6 The logic circuit diagram for realizing the "half subtracter" logic by using the cascade majority gate spin logic device.

[0065] Table 1 is the magnetization direction of the second ferromagnetic layer and the free layer of each MTJ in the "half subtracter" function

[0066]

[0067] Table 1

[0068] As shown in Table 1, the cascade majority gate spin logic device provided by the application realizes the "half subtracter" function, which includes four majority gate spin logic devices, which are respectively denoted as majority gate spin logic device 1, majority gate spin logic device 2, majority gate spin logic device 3 and majority gate spin logic device 4.

[0069] The control current parallel to the film surface is injected into the control MTJ's abnormal orbit torque layer of the majority gate spin logic device 1 and the control MTJ's abnormal orbit torque layer of the majority gate spin logic device 2, so that they are all in the low resistance state (0 state), and the majority gate spin logic device 1 and the majority gate spin logic device 2 realize the "and" logic

[0070] The control current is injected into the anomalous orbital moment layer of the control MTJ of the majority gate spin logic device 3 in parallel to the film surface to make it in high resistance state (1 state), the output MTJ of the majority gate spin logic device 1 and the input MTJ1 of the spin majority gate logic device 3 are cascaded through copper wire, the output MTJ of the majority gate spin logic device 2 and the input MTJ2 of the spin majority gate logic device 3 are cascaded through copper wire, as the "Diff" group.

[0071] The control current is injected into the anomalous orbital moment layer of the control MTJ of the majority gate spin logic device 4 in parallel to the film surface to make it in low resistance state (0 state), the majority gate spin logic device 4 realizes "and" logic, as the "Borrow" group.

[0072] The output MTJ of the majority gate spin logic device 3 is as the "Diff" output end to realize half subtractor logic, the output MTJ of the majority gate spin logic device 4 is as the "Borrow" output end to realize half subtractor logic, the input MTJ1 of the majority gate spin logic device 1, the input MTJ1 of the majority gate spin logic device 2 and the input MTJ1 of the majority gate spin device 4 are collectively as the minuend input end to realize half subtractor logic, the input MTJ2 of the majority gate spin logic device 1, the input MTJ2 of the majority gate spin logic device 2 and the input MTJ2 of the majority gate spin device 4 are collectively as the subtrahend input end to realize half subtractor logic.

[0073] The basic principles of the present application are described above in combination with specific embodiments, however, it should be pointed out that the advantages, advantages, effects and the like mentioned in the present application are only examples and not limitations, and these advantages, advantages, effects and the like cannot be considered as the must-have of each embodiment of the present application. In addition, the above disclosed specific details are only for the purpose of example and understanding, and are not limited to the above specific details to realize the present application.

[0074] The above description has been given for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof.

Claims

1. A spin-orbit torque magnetic tunnel junction, comprising: The application relates to a spintronic device, which comprises, from top to bottom, an electrode layer, an artificial antiferromagnetic reference layer, an insulating tunnel layer, a magnetic free layer and an abnormal spin-orbit torque layer, wherein the artificial antiferromagnetic reference layer comprises, from top to bottom, a first ferromagnetic layer, a non-magnetic spacer layer and a second ferromagnetic layer, the first ferromagnetic layer has a fixed direction of perpendicular magnetization; the electrode layer in contact with the first ferromagnetic layer has an in-plane polarization to adjust the magnetization direction of the second ferromagnetic layer, the magnetic free layer has a variable direction of perpendicular magnetization, the polarization direction is adjusted to the vertical direction by applying a voltage to the electrode layer, to generate a charge transfer and a ferroelectric polarization electric field in the vertical direction, so that the artificial antiferromagnetic reference layer is switched between an antiferromagnetic coupling state and a ferromagnetic coupling state, thereby changing the magnetization direction of the second ferromagnetic layer in the artificial antiferromagnetic reference layer, realizing a logic function; the abnormal spin-orbit torque layer in contact with the magnetic free layer has an in-plane magnetization direction to generate an abnormal spin Hall effect, so that the magnetization of the magnetic free layer is flipped, thereby changing the spin-orbit torque magnetic tunnel junction resistance state, realizing a logic function.

2. The spin-orbit torque magnetic tunnel junction of claim 1, wherein, By applying an in-plane current to the abnormal spin-orbit torque layer, an out-of-plane spin current is generated according to the abnormal spin Hall effect, the spin current flows into the magnetic free layer, and the magnetization direction of the magnetic free layer is flipped to the same direction as the spin polarization direction, realizing switching of the spin-orbit torque magnetic tunnel junction between a high resistance state and a low resistance state.

3. The spin-orbit torque magnetic tunnel junction of claim 2, wherein, The anomalous spin-orbit moment layer is composed of magnetic materials with a magnetic point group of 1, , , and , including Mn2ScSbO6, Cr2S3, Fe4O5, GaFeO3, ScFeO3, FeF3, NdFeO3.

4. The spin-orbit torque magnetic tunnel junction of claim 1, wherein, The electrode layer is formed of an insulating or semiconductor ferroelectric material, and the semiconductor ferroelectric material includes BaTiO3, BiFeO3, PbTiO3, SrTiO3 and HZO.

5. The spin-orbit torque magnetic tunnel junction of claim 1, wherein, The magnetic free layer comprises a magnetic material providing TMR and perpendicular anisotropy, and the magnetic material with perpendicular anisotropy includes CoFe, CoCrPt and CoFeB.

6. The spin-orbit torque magnetic tunnel junction of claim 1, wherein, The first ferromagnetic layer and the second ferromagnetic layer are magnetic materials with interlayer coupling strength and perpendicular anisotropy, which include Ni, CoCrPt, (Co / Pd) m or (Co / Pt) n wherein m, n refer to the number of repetitions of the multilayer stack; the non-magnetic spacer layer includes Au, Cu, Ag, Re, Ru, Os, Rh.

7. A majority gate spin logic device, comprising: It comprises four spin-orbit torque magnetic tunnel junctions as claimed in any one of claims 1-6, the four magnetic tunnel junctions are sequentially recorded as input MTJ1, input MTJ2, control MTJ and output MTJ, the free layer magnetization direction of the input MTJ1, the free layer magnetization direction of the input MTJ2, the free magnetization direction of the control MTJ are determined by the direction and size of the in-plane current applied to the anomalous spin-orbit torque layer, and the free layer magnetization direction of the output MTJ is determined by the free layer magnetization direction of the input MTJ1, the free layer magnetization direction of the input MTJ2 and the free magnetization direction of the control MTJ; the resistance state of the output MTJ is determined by the free layer magnetization direction and the magnetization direction of the insulating tunnel layer; after the in-plane current is applied to the anomalous spin-orbit torque layer, the domain wall moves from the positions of the input MTJ1, the input MTJ2 and the control MTJ to the output MTJ; the free layer magnetization direction is determined by the movement of the domain wall, when the control MTJ is in a high resistance state, the output MTJ and the input MTJ1 and the input MTJ2 realize "or" logic, at this time the first ferromagnetic layer and the second ferromagnetic layer of the control output MTJ are flipped from the antiferromagnetic coupling state to the ferromagnetic coupling state, and the output MTJ and the input MTJ1 and the input MTJ2 realize "or not" logic; when the control MTJ is in a low resistance state, the output MTJ and the input MTJ1 and the input MTJ2 realize "and" logic, at this time the first ferromagnetic layer and the second ferromagnetic layer of the control output MTJ are flipped from the antiferromagnetic coupling state to the ferromagnetic coupling state, and the output MTJ and the input MTJ1 and the input MTJ2 realize "and not" logic.

8. The majority gate spin logic device of claim 7, wherein, It is a cross-shaped structure, and the cross-shaped structure has four branches, two of which are input branches, one is a control branch, and one is an output branch; The input MTJ1 and the input MTJ2 are respectively located at the endpoints of the two input branches, the control MTJ is located at the endpoint of the control branch, and the output MTJ is located at the endpoint of the output branch.

9. A cascaded majority gate spin logic device, comprising: It comprises four majority gate spin logic devices as claimed in claim 7 or 8, which are recorded as majority gate spin logic device 1, majority gate spin logic device 2, majority gate spin logic device 3 and majority gate spin logic device 4, respectively, the output MTJ free layer of the majority gate spin logic device 1 and the input MTJ1 free layer of the majority gate spin logic device 3 are cascaded through copper wires, the output MTJ free layer of the majority gate spin logic device 2 and the input MTJ2 free layer of the majority gate spin logic device 3 are cascaded through copper wires, and the majority gate spin logic device 1, the majority gate spin logic device 2 and the majority gate spin logic device 3 jointly constitute a "Diff" output group, and the majority gate spin logic device 4 serves as a "Borrow" output group. The input current I1 parallel to the film plane is injected into the abnormal spin orbit torque layer of the input MTJ1 of the majority gate spin logic device 1; the input current I2 parallel to the film plane is injected into the abnormal spin orbit torque layer of the input MTJ2 of the majority gate spin logic device 1; the control current J1 parallel to the film plane is injected into the abnormal spin orbit torque layer of the control MTJ of the majority gate spin logic device 1 to make it in a low resistance state, and the majority gate spin logic device 1 realizes the "and" logic; The input current I3 parallel to the film plane is injected into the abnormal spin orbit torque layer of the input MTJ1 of the majority gate spin logic device 2, the input current I3 is the same size as the input current I1 and opposite in direction; the input current I4 parallel to the film plane is injected into the abnormal spin orbit torque layer of the input MTJ2 of the majority gate spin logic device 2, the input current I4 is the same size as the input current I2 and opposite in direction; the control current J2 parallel to the film plane is injected into the abnormal spin orbit torque layer of the control MTJ of the majority gate spin logic device 2 to make it in a low resistance state, the control current J1 and the control current J2 are the same size and the same direction, so that the majority gate spin logic device 2 realizes the "and" logic; The control current J3 parallel to the film plane is injected into the abnormal spin orbit torque layer of the control MTJ of the majority gate spin logic device 3 to make it in a high resistance state, wherein the control current J3 is the same size as the control current J1 and the control current J2 and opposite in direction, and the cascade majority gate spin logic device realizes the "exclusive or" logic; The input current I5 parallel to the film plane is injected into the abnormal spin orbit torque layer of the input MTJ1 of the majority gate spin logic device 4, the input current I5 is the same size as the input current I1 and opposite in direction; the input current I6 parallel to the film plane is injected into the abnormal spin orbit torque layer of the input MTJ2 of the majority gate spin logic device 4, the input current I6 is the same size as the input current I2 and opposite in direction; the control current J4 parallel to the film plane is injected into the abnormal spin orbit torque layer of the control MTJ of the majority gate spin logic device 1 to make it in a low resistance state, the control current J4 is the same size as the control current J1 and the control current J2 and the same direction, and the majority gate spin logic device 4 realizes the "and" logic; The output MTJ of the majority gate spin logic device 3 is used as a "Diff" output terminal for realizing the half subtractor logic, the output MTJ of the majority gate spin logic device 4 is used as a "Borrow" output terminal for realizing the half subtractor logic, the input MTJ1 of the majority gate spin logic device 1, the input MTJ1 of the majority gate spin logic device 2 and the input MTJ1 of the majority gate spin logic device 4 are used as the minuend input terminals for realizing the half subtractor logic, and the input MTJ2 of the majority gate spin logic device 1, the input MTJ2 of the majority gate spin logic device 2 and the input MTJ2 of the majority gate spin logic device 4 are used as the subtrahend input terminals for realizing the half subtractor logic.

10. The cascaded majority gate spin logic device of claim 9, wherein, It is a symmetric structure for realizing the one-bit half subtractor function.

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