Electrical read-write memory device based on anti-ferromagnetic neel vector 180-degree overturning, preparation method and read-write method

Abstract

The invention discloses an electric read-write memory device based on anti-ferromagnetic neel vector 180-degree overturning, a preparation method and a read-write method. The electrical read-write memory device comprises a substrate layer, an antiferromagnetic layer and a spin source layer which are sequentially stacked from bottom to top and form a heterostructure, the substrate layer is made of a single crystal substrate on which an antiferromagnetic layer can be epitaxially grown; the antiferromagnetic layer is made of a collinear antiferromagnetic material with an abnormal Hall effect or a staggered magnet with the abnormal Hall effect; the material of the spin source layer has a spin current generation capability. According to the memory, the current pulse is utilized to drive 180-degree overturning of the Nell vector, and the Nell vector before and after 180-degree overturning has a high abnormal Hall resistance state and a low abnormal Hall resistance state and can be used for storing information '0' and '1'. Not only is the connotation of the interaction of the spin current and the antiferromagnetic neel vector enriched, but also a foundation is laid for constructing a nonvolatile magnetic random access memory with high density, high read-write speed and low power consumption.

Description

Technical Field

[0001] The invention relates to an antiferromagnetic memory device capable of electrically reading and writing, and in particular to an electrical read-write memory device based on 180-degree flipping of an antiferromagnetic Née vector, a preparation method and a read-write method. The antiferromagnetic Née vector is flipped 180 degrees by using a spin-orbit torque, and the antiferromagnetic Née vector is read out by using an anomalous Hall effect. The invention belongs to the field of electronic information materials. Background Art

[0002] Spintronic devices utilize the spin freedom of electrons and have shown great potential in the development and construction of new non-volatile information storage devices with high speed, low power consumption and high density, which is in line with the development requirements of big data, cloud computing and artificial intelligence. In recent years, antiferromagnetic materials have become an important development direction for ultrafast and ultra-high density information storage due to their advantages such as no stray fields, high intrinsic frequency and resistance to external magnetic field interference, and are expected to be applied to high-frequency electronic devices to prevent electromagnetic threats. Given the characteristics of zero net magnetic moment and insensitivity to external magnetic fields, how to achieve electrical reversal and detection of antiferromagnetic Née vectors is a key scientific issue in realizing information reading and writing in antiferromagnetic magnetic storage technology. However, the current writing technology is limited to electrically driving the antiferromagnetic Née vector to flip 90 degrees or 120 degrees, and the reading technology is limited to using magnetoresistance, specifically using field-like torque in antiferromagnetic CuMnAs or antiferromagnetic Mn2Au with broken antiferromagnetic sublattice symmetry, or using damping-like torque in antiferromagnetic NiO and antiferromagnetic Fe2O3, which requires the use of eight-terminal devices that are difficult to integrate. Electrically driving the antiferromagnetic Née vector to flip 180 degrees and electrically reading it out is a technology that is closely related to the electrical operation and reading of the "0" and "1" bit states of information technology, has the potential of a two-terminal device, and is highly desired but has not yet been realized. Summary of the invention

[0003] The invention aims to provide an electrical read-write storage device and a read-write method based on 180-degree flipping of an antiferromagnetic Née vector, which utilizes a spin-orbit torque to drive the antiferromagnetic Née vector to flip 180 degrees, utilizes the anomalous Hall effect to read the antiferromagnetic Née vector, and realizes an electrically read-write storage device by 180-degree flipping of the antiferromagnetic Née vector, which not only enriches the connotation of the interaction between the spin current and the antiferromagnetic Née vector, but also lays a foundation for constructing a non-volatile magnetic random access memory with high density, high read-write speed and low power consumption.

[0004] To achieve the above object, the present invention adopts the following technical solution:

[0005] In a first aspect, the present invention provides an electrical read-write memory device, comprising: a substrate layer, an antiferromagnetic layer and a spin source layer stacked in sequence from bottom to top to form a heterostructure;

[0006] The material of the substrate layer is a single crystal substrate on which an antiferromagnetic layer can be epitaxially grown;

[0007] The material of the antiferromagnetic layer is a collinear antiferromagnetic material with an anomalous Hall effect or an interlaced magnet with an anomalous Hall effect;

[0008] The material of the spin source layer has the ability to generate spin current.

[0009] In the above-mentioned electrical read-write storage device, the single crystal substrate is an aluminum oxide substrate Al2O3, a magnesium oxide substrate MgO, a lanthanum aluminate substrate LaAlO3, a lead magnesium niobate-lead titanate substrate Pb(Mg 1 / 3 Nb 2 / 3 ) 0.7 Ti 0.3 O3 or strontium titanate substrate SrTiO3.

[0010] In the above-mentioned electrical read-write storage device, the collinear antiferromagnetic material with anomalous Hall effect or the staggered magnetic material with anomalous Hall effect is Mn5Si3 or CrSb.

[0011] In the above-mentioned electrical read-write memory device, the thickness of the antiferromagnetic layer is 3-50 nm.

[0012] In the above-mentioned electrical read-write memory device, the material of the spin source layer is heavy metal Pt, Ta or W.

[0013] In the above-mentioned electrical read-write memory device, the thickness of the spin source layer is 1 to 20 nm.

[0014] The electrical read-write memory device further comprises a first electrode, a second electrode, a third electrode and a fourth electrode;

[0015] With the stacking direction as the vertical direction, the first electrode and the second electrode are respectively arranged on opposite sides of a first horizontal direction, the third electrode and the fourth electrode are respectively arranged on opposite sides of a second horizontal direction, and the first horizontal direction is perpendicular to the second horizontal direction.

[0016] In a second aspect, the present invention provides a method for preparing the electrical read-write memory device described in any one of the above items, comprising:

[0017] forming the antiferromagnetic layer on the surface of the substrate layer;

[0018] The spin source layer is formed on a surface of the antiferromagnetic layer away from the substrate layer.

[0019] In the above-mentioned preparation method, the forming of the antiferromagnetic layer comprises: performing a film forming process on the surface of the substrate layer;

[0020] The forming of the spin source layer includes: performing a film forming process on the surface of the antiferromagnetic layer.

[0021] In a third aspect, the present invention provides an electrical read-write method for an electrical read-write storage device as described in any one of the above, comprising:

[0022] Taking the stacking direction as the vertical direction, applying a pulse current along a first horizontal direction to the storage device, the pulse current flowing through the spin source layer generates transverse spin polarization through the spin Hall effect, and is vertically injected into the antiferromagnetic layer, generating a spin-orbit torque on the antiferromagnetic Née vector in the antiferromagnetic layer, and under the action of a magnetic field parallel to the first horizontal direction, the spin-orbit torque drives the Née vector to flip 180 degrees, thereby realizing electrical writing of the storage device;

[0023] The abnormal Hall voltage in a second horizontal direction is read, where the second horizontal direction is perpendicular to the first horizontal direction, to achieve electrical readout of the memory device.

[0024] The present invention has the following beneficial effects:

[0025] The present invention provides an electrical read-write storage device based on 180-degree flipping of the antiferromagnetic Née vector, which uses the spin-orbit torque to drive the antiferromagnetic Née vector to flip 180 degrees, and uses the anomalous Hall effect to read the antiferromagnetic Née vector. It has the following advantages: antiferromagnetic materials have the advantages of anti-magnetic field interference and fast operation speed; the ratio of the anomalous Hall coercive force to the critical write current density is more than 4 times that of the traditional ferromagnetic system, and has the advantage of low power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The schematic diagram of the principle of an electrical read-write storage device based on 180-degree flipping of the antiferromagnetic Née vector provided by an embodiment of the present invention. The marks in the figure are as follows: 1-substrate layer; 2-antiferromagnetic layer; 3-spin source layer; 4-write current positive terminal; 5-write current negative terminal; 6-read voltage positive terminal; 7-read voltage negative terminal; 8-magnetic field along the write current direction.

[0027] Figure 2 The schematic diagram of the device structure of the electrical read-write storage device based on the 180-degree flip of the antiferromagnetic Neel vector provided by the embodiment of the present invention. Figure 1 Consistent.

[0028] Figure 3 In the embodiment 1 of the present invention, in the Al2O3 (0001) substrate / colinear antiferromagnetic film Mn5Si3 (6nm) / heavy metal Pt (10nm) storage device, Figure 1 When positive and negative current pulses of different sizes are passed through the 4-5 terminals shown, the voltage changes at the 6-7 terminals are recorded using a nanovoltmeter.

[0029] Figure 4 In the second embodiment of the present invention, in a LaAlO3 (110) substrate / collinear antiferromagnetic film CrSb (40nm) / heavy metal Pt (5nm) storage device, Figure 1 When positive and negative current pulses of different sizes are passed through the 4-5 terminals shown, the voltage changes at the 6-7 terminals are recorded using a nanovoltmeter. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0031] In the following, the terms "first", "second", etc. are used only for convenience of description and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0032] In addition, in the embodiments of the present application, directional terms or positional relationships such as "up", "down", "left", "right", "horizontal" and "vertical" are based on the directional or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred system or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0033] The electrical read-write storage device based on 180-degree flipping of the antiferromagnetic Neel vector provided by the embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0034] In a first aspect, the present invention provides an electrical read-write storage device, such as Figure 1 As shown, it includes: a substrate layer 1, an antiferromagnetic layer 2 and a spin source layer 3 which are stacked in sequence from bottom to top and constitute a heterostructure; the material of the substrate layer 1 is a single crystal substrate on which the antiferromagnetic layer 2 can be epitaxially grown; the material of the antiferromagnetic layer 2 is a colinear antiferromagnetic material with an anomalous Hall effect or an interdigitated magnet with an anomalous Hall effect; the spin source layer 3 has the ability to generate spin current.

[0035] The specific implementation method of the electrical read-write storage device of the present invention is as follows: Figure 1As shown, a pulse current is introduced into the electrical read-write storage device along the 4-5 terminal, and the pulse current flowing through the heavy metal layer 3 generates transverse spin polarization through the spin Hall effect, and is vertically injected into the antiferromagnetic layer 2, generating a spin-orbit torque effect on the antiferromagnetic Née vector in the antiferromagnetic layer 2; under the action of an auxiliary magnetic field parallel to the 4-5 terminal, the spin-orbit torque drives the Née vector to flip 180 degrees; and the 180-degree flip of the Née vector is read out by reading the abnormal Hall voltage at the 6-7 terminal. The present invention utilizes the spin-orbit torque to electrically drive the antiferromagnetic Née vector to flip 180 degrees and utilizes the abnormal Hall effect to electrically read out the direction of the antiferromagnetic Née vector before and after the 180-degree flip.

[0036] According to the present invention, the single crystal substrate on which the antiferromagnetic layer can be epitaxially grown includes but is not limited to an aluminum oxide substrate Al2O3, a magnesium oxide substrate MgO, a lanthanum aluminate substrate LaAlO3, a lead magnesium niobate-lead titanate substrate Pb(Mg 1 / 3 Nb 2 / 3 ) 0.7 Ti 0.3 O3 (PMN-PT), strontium titanate substrate SrTiO3; in a specific embodiment of the present invention, the single crystal substrate on which the antiferromagnetic layer can be epitaxially grown is Al2O3 (0001) or LaAlO3 (110). The thickness of the substrate layer is not limited, such as 0.5-1 mm, 0.5 mm or 1 mm.

[0037] According to the present invention, the collinear antiferromagnetic material with anomalous Hall effect may be Mn5Si3 or CrSb; preferably, the thickness of the antiferromagnetic layer 2 is in the range of 3 to 50 nm, including but not limited to 6 to 40 nm, 6 nm or 40 nm.

[0038] According to the present invention, the material of the spin source layer 3 includes but is not limited to heavy metals Pt, Ta or W; preferably, the thickness of the spin source layer 3 ranges from 1 to 20 nm, including but not limited to 5 to 10 nm, 5 nm or 10 nm.

[0039] According to the present invention, the electrical read-write storage device of the present invention also includes a first electrode, a second electrode, a third electrode and a fourth electrode; with the stacking direction as the vertical direction, the first electrode and the second electrode are respectively arranged on opposite sides of the first horizontal direction (that is, the first electrode and the second electrode are respectively arranged on opposite sides of the 4-5 end), the third electrode and the fourth electrode are respectively arranged on opposite sides of the second horizontal direction, and the first horizontal direction is perpendicular to the second horizontal direction (that is, the third electrode and the fourth electrode are respectively arranged on opposite sides of the 6-7 end).

[0040] Preferably, if Figure 2As shown, the electrical read-write storage device is cross-shaped, the first electrode and the second electrode are respectively arranged on opposite sides of one cross side, and the third electrode and the fourth electrode are respectively arranged on opposite sides of another cross side. Among them, the first electrode and the second electrode are used to pass a pulse write current; the third electrode and the fourth electrode are used to read the anomalous Hall voltage. Specifically, the substrate layer, the antiferromagnetic layer and the spin source layer, which are stacked from bottom to top and constitute a heterostructure, can be a four-terminal cross bar, such as a four-terminal cross bar with a specification of 4μm (voltage end) × 6μm (current end); the first electrode, the second electrode, the third electrode and the fourth electrode are respectively connected to the four ends of the four-terminal cross bar.

[0041] The materials of the first electrode, the second electrode, the third electrode and the fourth electrode are not limited. Preferably, the first electrode, the second electrode, the third electrode and the fourth electrode are all Ti / Au composite electrodes, wherein the thickness of the Ti metal layer is 10 nm and the thickness of the Au layer is 70 nm.

[0042] In a second aspect, the present invention provides a method for preparing an electrical read-write memory device, comprising: forming an antiferromagnetic layer 2 on the surface of a substrate layer 1; and forming a spin source layer 3 on the surface of the antiferromagnetic layer 2 away from the substrate layer 1.

[0043] According to the present invention, forming the antiferromagnetic layer 2 includes: performing film forming treatment on the surface of the substrate layer 1, and the film forming treatment method can be specifically coating, which can be selected according to the film material, such as using magnetron sputtering to deposit Mn5Si3 or CrSb. For example, the material of the antiferromagnetic layer 2 is Mn5Si3, and the Mn5Si3 film is deposited by co-sputtering of Mn target and Si target; specifically, the deposition conditions are as follows: The Mn5Si3 film was deposited on the Al2O3 (0001) substrate at a speed of 500 ℃. The background vacuum before sputtering the Mn5Si3 film in the chamber was 5×10 -8 Torr, the argon pressure during sputtering is 3mtorr; after the Mn5Si3 film is deposited, the temperature is raised to 600℃ and annealed for 2 hours. The material of the antiferromagnetic layer 2 is CrSb, and the CrSb film is deposited by co-sputtering of Cr target and Sb target; specifically, the deposition conditions are as follows: The CrSb film was deposited on the LaAlO3(110) substrate at a speed of 1000 Å. The background vacuum before sputtering the CrSb film in the chamber was 7×10 -8 Torr, the argon pressure during sputtering is 3mtorr; after the film is deposited, the temperature is raised to 470°C for annealing for 30 minutes. The formation of the spin source layer 3 includes: performing a film forming process on the surface of the antiferromagnetic layer 2, and the film forming process can be specifically a coating process, which can be selected according to the film material, such as using magnetron sputtering to deposit heavy metal Pt; specifically, the deposition conditions are as follows: the background vacuum before the cavity sputtering the Pt film is 5×10 -8Torr, and the argon pressure during sputtering is 3mtorr.

[0044] In a third aspect, the present invention provides an electrical read-write method for an electrical read-write storage device, comprising: taking the stacking direction as the vertical direction, applying a first horizontal direction (such as Figure 1 The pulse current flowing through the spin source layer 3 generates transverse spin polarization through the spin Hall effect, and is vertically injected into the antiferromagnetic layer 2, generating a spin-orbit torque on the antiferromagnetic Née vector in the antiferromagnetic layer 2, parallel to the first horizontal direction (such as Figure 1 Under the auxiliary magnetic field of the magnetic field 8 along the writing current direction, the spin-orbit torque drives the Née vector to flip 180 degrees, realizing the electrical writing of the storage device; reading the second horizontal direction (such as Figure 1 The abnormal Hall voltage at the middle 6-7 terminal) is generated in the second horizontal direction and is perpendicular to the first horizontal direction, thereby realizing electrical readout of the memory device.

[0045] In the present invention, according to the antiferromagnetic Neel temperature of each layer of material in the electrical read-write memory device of the present invention, a suitable temperature is selected to read and write the electrical memory device. For example, in one embodiment of the present invention, the temperature of the electrical read-write memory device is reduced to 180K and an auxiliary magnetic field is applied, because the antiferromagnetic Neel temperature of Mn5Si3 is below room temperature; in another specific embodiment of the present invention, the temperature of the electrical read-write memory device is maintained at room temperature and an auxiliary magnetic field is applied, because the antiferromagnetic Neel temperature of CrSb is above room temperature. In the present invention, room temperature refers to 10 to 30°C, preferably 15 to 30°C, and more preferably 20 to 25°C.

[0046] The present invention is based on the electrical read-write storage device of 180-degree flipping of the antiferromagnetic Née vector. The current pulse drives the 180-degree flipping of the Née vector. The Née vector before and after the 180-degree flipping has two abnormal Hall resistance states, one high and one low, which can be used to store information "0" and "1". The write current pulse flows through the spin source layer to generate a spin current. The spin current acts on the Née vector of the antiferromagnetic layer to generate a spin-orbit torque, driving the 180-degree flipping of the Née vector, thereby realizing the electrical writing of the memory. The read current pulse flows through the antiferromagnetic layer, and uses the abnormal Hall effect to generate a potential difference in the lateral direction. The Née vector brings a high and a low lateral potential difference before and after the 180-degree flipping, thereby realizing the electrical reading of the memory. In a specific embodiment of the present invention, when the absolute value of the pulse current reaches 30 mA or more, a change in the Hall voltage occurs, which means that the 180-degree flipping of the antiferromagnetic Née vector is formed. The present invention realizes an electrically readable and writable storage device by 180-degree flipping of the antiferromagnetic Née vector, which not only enriches the connotation of the interaction between the spin current and the antiferromagnetic Née vector, but also lays a foundation for constructing a non-volatile magnetic random access memory with high density, high read and write speed and low power consumption.

[0047] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0048] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial channels.

[0049] Example 1: Al2O3(0001) / Mn5Si3(6nm) / Pt(10nm) electrical read / write storage device based on 180-degree flipping of antiferromagnetic Néel vector.

[0050] The Mn5Si3 (6nm) / Pt (10nm) heterojunction sample was deposited on Al2O3 (0001) substrate (0.5mm) by magnetron sputtering.

[0051] At 465℃, Mn target and Si target were co-sputtered to produce The Mn5Si3 film was deposited on the Al2O3 (0001) substrate at a speed of 500 nm. The background vacuum before sputtering the Mn5Si3 film in the chamber was 5×10 -8 Torr, and the argon pressure during sputtering was 3mtorr. After the Mn5Si3 film was deposited, the temperature was raised to 600℃ for annealing for 2 hours. After cooling to room temperature, 10nm Pt was deposited. The background vacuum before sputtering the Pt film in the chamber was 5×10 -8 Torr, and the argon pressure during sputtering is 3mtorr.

[0052] The Mn5Si3(6nm) / Pt(10nm) heterojunction sample was processed into a 4μm×6μm four-terminal cross bar by using the micro-nano processing technology of ultraviolet exposure and argon ion etching. Then, Ti(10nm) / Au(70nm) electrodes were prepared and connected to the four-terminal cross bar by using the micro-nano processing technology of ultraviolet exposure, electron beam evaporation and peeling to form an electrical read-write storage device.

[0053] During the test, an ultrasonic aluminum wire bonding machine is used to connect the 4-5 current terminal and 6-7 voltage terminal of the electrical read-write storage device to an ammeter and a nanovoltmeter.

[0054] The electrical read-write storage device is placed in a low-temperature sample chamber, and the low-temperature sample chamber is placed in a magnetic field along the 4-5 ends applied by an electromagnet.

[0055] The temperature of the electrical read-write memory device is lowered to 180K, and an auxiliary magnetic field of 0.2kOe or -0.2kOe is applied along the 4-5 end.

[0056] like Figure 3 As shown, a pulse write current with a pulse width of 1 ms, which changes from +46 mA to -46 mA and then to +46 mA, is passed to the 4-5 current terminal. After waiting for 10 seconds, a 2 mA DC read current is passed to the 4-5 current terminal, and the Hall voltage at the 6-7 voltage terminal is recorded. It can be seen that when the absolute value of the pulse current reaches more than 30 mA, a change in the Hall voltage occurs, which means that a 180-degree flip of the antiferromagnetic Née vector is formed. For auxiliary magnetic fields of opposite polarities of 0.2 kOe and -0.2 kOe, the polarity of the 180-degree flip of the antiferromagnetic Née vector induced by the positive and negative pulse currents is opposite, which meets the basic symmetry requirements of the spin-orbit torque flipping magnetic moment. The ratio of the anomalous Hall coercive force to the critical write current density of the electrical read-write storage device of this example is 4 mTcm 2 MA -1 , while the ratio of the anomalous Hall coercivity to the critical writing current density of the traditional ferromagnetic system is about 1 mT cm 2 MA -1 about.

[0057] The mechanism of the pulse writing current driving the antiferromagnetic Née vector to flip 180 degrees is as follows: the pulse current flowing through the Pt layer generates transverse spin polarization through the spin Hall effect, and is vertically injected into the antiferromagnetic Mn5Si3, generating a spin-orbit torque on the Née vector of the antiferromagnetic Mn5Si3. The spin-orbit torque induces the Née vector of Mn5Si3 to produce a slight deflection in the direction of the transverse spin polarization, thereby generating an antiferromagnetic exchange torque under the action of the antiferromagnetic exchange field, driving the Née vector to rotate. The auxiliary field can apply Zeeman energy to the tiny net magnetic moment generated by the Dzyaloshinskii-Moriya interaction of the antiferromagnetic Mn5Si3, thereby breaking the symmetry of the 180-degree flip of the Née vector of Mn5Si3 and achieving a decisive 180-degree flip of the Née vector.

[0058] Example 2: CrSb (40nm) / Pt (5nm) electrical read-write storage device based on 180-degree flipping of the antiferromagnetic Neel vector.

[0059] CrSb (40 nm) / Pt (5 nm) heterojunction samples were deposited on LaAlO3 (110) substrates (0.5 mm) by magnetron sputtering.

[0060] At 350℃, Cr target and Sb target were co-sputtered to The CrSb film was deposited on the LaAlO3(110) substrate at a speed of 1000 rpm. The background vacuum before sputtering the CrSb film was 7×10 -8Torr, and the argon pressure during sputtering was 3mtorr. After the film was deposited, the temperature was raised to 470℃ for annealing for 30 minutes. After cooling to room temperature, 5nm Pt was deposited. The background vacuum before sputtering the Pt film in the chamber was 5×10 -8 Torr, and the argon pressure during sputtering is 3mtorr.

[0061] The CrSb (40 nm) / Pt (5 nm) heterojunction sample is processed into a 4 μm×6 μm four-terminal cross stripe by using a micro-nano processing technology of ultraviolet exposure and argon ion etching to become the electrical read-write storage device.

[0062] During the test, an ultrasonic aluminum wire bonding machine is used to connect the 4-5 current terminal and the 6-7 voltage terminal of the electrical read-write storage device to an ammeter and a nanovoltmeter.

[0063] The electrical read-write storage device is placed in the sample cavity, and the sample cavity is placed in the magnetic field along the 4-5 end applied by the electromagnet.

[0064] Apply an auxiliary magnetic field of 0.8 kOe or -0.8 kOe along the 4-5 ends of the electrical read-write memory device at room temperature.

[0065] The experimental results are as follows Figure 4 As shown. As in Example 1, a pulse write current with a pulse width of 1 ms, which varies from +46 mA to -46 mA and then to +46 mA, is passed through the 4-5 current terminal. After waiting for 10 seconds, a 2 mA DC read current is passed through the 4-5 current terminal, and the Hall voltage at the 6-7 voltage terminal is recorded. It can be seen that when the absolute value of the pulse current reaches more than 30 mA, a change in the Hall voltage occurs, which means that a 180-degree flip of the antiferromagnetic Née vector is formed. For auxiliary magnetic fields of opposite polarities of 0.8 kOe and -0.8 kOe, the polarities of the 180-degree flip of the antiferromagnetic Née vector induced by the positive and negative pulse currents are opposite, which meets the basic symmetry requirements of the spin-orbit torque flipping magnetic moment. The ratio of the anomalous Hall coercive force to the critical write current density of the electrical read-write storage device of this example is 5 mT cm 2 MA -1 , while the ratio of the anomalous Hall coercivity to the critical writing current density of the traditional ferromagnetic system is about 1 mT cm 2 MA -1 about.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electrical read-write storage device, characterized in that: include: A substrate layer, an antiferromagnetic layer and a spin source layer are stacked in sequence from bottom to top to form a heterostructure; The material of the substrate layer is a single crystal substrate on which an antiferromagnetic layer can be epitaxially grown; The material of the antiferromagnetic layer is a collinear antiferromagnetic material with an anomalous Hall effect or an interlaced magnet with an anomalous Hall effect; The material of the spin source layer has the ability to generate spin current.

2. The electrical read-write storage device according to claim 1, characterized in that: The single crystal substrate is an aluminum oxide substrate Al2O3, a magnesium oxide substrate MgO, a lanthanum aluminate substrate LaAlO3, a lead magnesium niobate-lead titanate substrate Pb(Mg 1 / 3 Nb 2 / 3 ) 0.7 Ti 0.3 O3 or strontium titanate substrate SrTiO3.

3. The electrical read-write storage device according to claim 1 or 2, characterized in that: The collinear antiferromagnetic material with anomalous Hall effect or the staggered magnet material with anomalous Hall effect is Mn5Si3 or CrSb.

4. The electrical read-write storage device according to any one of claims 1 to 3, characterized in that: The thickness of the antiferromagnetic layer is 3-50 nm.

5. The electrical read-write storage device according to any one of claims 1 to 4, characterized in that: The spin source layer is made of heavy metal Pt, Ta or W.

6. The electrical read-write storage device according to any one of claims 1 to 5, characterized in that: The thickness of the spin source layer is 1-20 nm.

7. The electrical read-write storage device according to any one of claims 1 to 6, characterized in that: Also includes a first electrode, a second electrode, a third electrode and a fourth electrode; With the stacking direction as the vertical direction, the first electrode and the second electrode are respectively arranged on opposite sides of a first horizontal direction, the third electrode and the fourth electrode are respectively arranged on opposite sides of a second horizontal direction, and the first horizontal direction is perpendicular to the second horizontal direction.

8. The method for preparing the electrical read-write memory device according to any one of claims 1 to 7, characterized in that: include: forming the antiferromagnetic layer on the surface of the substrate layer; The spin source layer is formed on a side of the antiferromagnetic layer away from the substrate layer.

9. The method for preparing an electrical read-write memory device according to claim 8, characterized in that: The forming of the antiferromagnetic layer comprises: performing film forming treatment on the surface of the substrate layer; The forming of the spin source layer includes: performing a film forming process on the surface of the antiferromagnetic layer.

10. The electrical read-write method of the electrical read-write storage device according to any one of claims 1 to 7, comprising: Taking the stacking direction as the vertical direction, applying a pulse current along a first horizontal direction to the storage device, the pulse current flowing through the spin source layer generates transverse spin polarization through the spin Hall effect, and is vertically injected into the antiferromagnetic layer, generating a spin-orbit torque on the antiferromagnetic Née vector in the antiferromagnetic layer, and under the action of a magnetic field parallel to the first horizontal direction, the spin-orbit torque drives the Née vector to flip 180 degrees, thereby realizing electrical writing of the storage device; The abnormal Hall voltage in a second horizontal direction is read, where the second horizontal direction is perpendicular to the first horizontal direction, to achieve electrical readout of the memory device.

Images