CN113782668B - Magnetization turning device based on track transfer torque and implementation method thereof - Google Patents
Magnetization turning device based on track transfer torque and implementation method thereof Download PDFInfo
- Publication number
- CN113782668B CN113782668B CN202111345093.8A CN202111345093A CN113782668B CN 113782668 B CN113782668 B CN 113782668B CN 202111345093 A CN202111345093 A CN 202111345093A CN 113782668 B CN113782668 B CN 113782668B
- Authority
- CN
- China
- Prior art keywords
- current
- heterojunction
- moment
- electrode
- source
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N52/00—Hall-effect devices
- H10N52/101—Semiconductor Hall-effect devices
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/1274—Structure or manufacture of heads, e.g. inductive with "composite" cores, i.e. cores composed in some parts of magnetic particles and in some other parts of magnetic metal layers
- G11B5/1276—Structure or manufacture of heads, e.g. inductive with "composite" cores, i.e. cores composed in some parts of magnetic particles and in some other parts of magnetic metal layers including at least one magnetic thin film
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N52/00—Hall-effect devices
- H10N52/01—Manufacture or treatment
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N52/00—Hall-effect devices
- H10N52/80—Constructional details
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Hall/Mr Elements (AREA)
- Mram Or Spin Memory Techniques (AREA)
Abstract
The invention discloses a magnetization overturning device based on track transfer torque and an implementation method thereof. Direct current write current is introduced through the source electrode and the drain electrode to generate polarization of out-of-plane orbital magnetic moment, so that an out-of-plane anti-damping moment effect is generated, and magnetization reversal of the perpendicular magnetic anisotropy free ferromagnetic layer can be realized under the out-of-plane anti-damping moment effect without additional magnetic field assistance, namely orbital transfer moment; the perpendicular magnetic anisotropy free ferromagnetic layer retains a changed magnetization state after the write current is removed, thereby having non-volatility; a direct current reading current is introduced through the source electrode and the drain electrode, and a Hall resistance of the heterojunction is obtained through the measuring electrode, so that the magnetization state of the perpendicular magnetic anisotropy free ferromagnetic layer is reflected; changing the direction of the write current to realize reverse track transfer torque so as to reversely turn the magnetization of the perpendicular magnetic anisotropy free ferromagnetic layer; the critical current required by the track transfer torque to realize magnetization reversal is smaller, so that the power consumption of the device can be greatly reduced.
Description
Technical Field
The invention relates to the field of spin electronics of condensed state physics, in particular to a perpendicular magnetic anisotropy magnetization switching device without the assistance of an external magnetic field and an implementation method thereof.
Background
Spintronics (spintronics) utilizes the freedom of the spin and magnetic moment of electrons to enable the solid-state device to be added with the spin and magnetic moment transport of electrons in addition to charge transport. Spintronics is an emerging subject and technology, and has application potential in the aspects of hard disk magnetic heads, magnetic random access memories, spin field emission transistors, spin light emitting diodes and the like. In the field of spintronics, one important finding is the Giant Magnetoresistance effect (Giant magnoresistance). The giant magnetoresistance effect refers to the phenomenon that the resistivity of a magnetic material has great change under the action of an external magnetic field. It is usually produced in a layered magnetic thin film structure. The structure, namely a magnetic tunneling junction, specifically comprises two ferromagnetic layers, which are separated by an insulator film. When the magnetization directions of the two ferromagnetic layers are the same, the carrier receives the minimum scattering related to spin, and the tunneling resistance of the system is in a low resistance state; when the magnetization directions of the two are opposite, the carrier is subjected to the largest spin-dependent scattering, and the tunneling resistance is in a high resistance state. The giant magnetoresistance effect has been successfully applied to hard disk magnetic heads, and has significant commercial value. The giant magnetoresistance effect has only used less than 10 years from physical findings (20% of the room temperature tunneling magnetoresistance effect was found in 1995) to material fabrication and mass production (> 270 Gbit/inch 2) of magnetic read head devices based on the giant magnetoresistance effect in 2005. From 1997 to date, magnetic read head products and their hard disks based on the above giant magnetoresistance effect have been widely used in network servers and desktop computers, laptop computers, digital cameras, and music players such as MP3, MP4, etc., significantly contributing to the progress of computer and information technology. Because of this, the nobel prize in 2007 awarded the discoverers of the giant magnetoresistance effect, Albert Fert and Peter Grunberg, to highlight their contributions to the scientific development of contemporary condensed-state physical and information materials.
However, to achieve the giant magnetoresistance effect, it is necessary to change the magnetization state of the free ferromagnetic layer in the magnetic thin film structure. In the past, people realize the change of the magnetization state by an external magnetic field, but the external magnetic field usually means larger power consumption, and simultaneously increases the complexity of the device, and limits the application range of the device. In 1996, Slonczewski and Berger theoretically and independently proposed a new spin-dependent effect, i.e., a current-induced magnetization switching effect, in which the magnetization direction of a ferromagnetic layer is changed, or even switched, not by an applied magnetic field, but by injecting a spin-polarized current. The technique of realizing magnetization switching by using the current effect is very important for the practical application of the giant magnetoresistance effect. Therefore, the switching of magnetization by using the current effect becomes an important issue in the field of spintronics, and the technology has important application value in the aspects of read-write magnetic heads, magnetic memory units, spin logic devices and the like.
At present, in the field of spintronics, three main current modes are used for realizing magnetization reversal by using current.
1. In the early application of giant magnetoresistance effect, the magnetization of the free ferromagnetic layer is switched by using a magnetic field generated by current, but the mode has the defects of high power consumption, difficult application in a nanoscale device, complex circuit design and the like.
2. Spin-transfer torque (STT), a new technique, achieves magnetization switching by a spin-polarized current rather than an oersted field generated by a current, as compared to switching magnetization by a magnetic field. When a current flows through the magnetic layer, the current will be polarized, forming a spin-polarized current. And current is introduced into the magnetic tunneling junction, and the spin momentum is transferred to the magnetic moment of the free layer by electrons, so that the direction of the magnetic moment of the free ferromagnetic layer is changed after the spin momentum is obtained, and the magnetization is switched. One important application scenario for implementing magnetization switching using the current effect is the read/write head. When the spin transfer torque technology is used, because current needs to be introduced into the tunneling junction when information is written and read, the read-write path is not separated, and the write current is larger, so that the insulation layer has the defects of serious joule heat accumulation, poor durability and the like.
3. Scientists further propose that spin-orbit torque (SOT) is realized by using spin-orbit coupling effect of materials to perform magnetization reversal, so as to successfully realize separation of read and write paths, and spin-orbit torque is a storage technology with higher speed, higher density and higher efficiency compared with spin-orbit torque. The Spin-Orbit torque refers to a Spin-Orbit Coupling (SOC) based on a material, and a Spin transfer torque is generated by using a Spin current induced by a charge flow, thereby achieving the purpose of regulating and controlling a magnetic memory cell. In general materials, electrons are spin degenerate; when spin-orbit coupling exists, the electrons are subjected to an equivalent magnetic field generated by the spin-orbit coupling during the motion process. Electrons with different spin directions are subjected to different equivalent magnetic field directions to generate shunt currents. When current flows, part of the current is converted into transverse net spin current, and the spin current spin polarization direction, the current direction and the spin current direction are 90 degrees. The flowing charge current generates a spin current perpendicular to the charge flow direction, i.e., the spin hall effect, thereby generating a spin-orbit torque. When the current is reversed, the spin polarization is also reversed, causing the spin-orbit moment to be reversed, resulting in an opposite effect on the magnetic moment of the free ferromagnetic layer. In some two-dimensional systems with broken symmetry (especially in the two-dimensional interface system of heterojunction, the environment around the electrons in the interface is different), the electrons do not have spin degeneracy, the equivalent Hamilton quantity of the system has an additional term related to spin-orbit coupling, and similar to the spin Hall effect, the conversion of current and spin current is also involved, so-called Rashba-Edelstein effect, and the spin-orbit moment is also generated by the effect.
In 2009, the spin-orbit torque effect was first observed in semiconductor (Ga, Mn) As and the torque was found to come from dreselhaus spin-orbit coupling effects characteristic of the sphalerite crystal structure. One year later, it was reported that the spin orbit moment caused by the interfacial Rashba effect was detected in Pt/Co/AlOx. Some heavy metals, such as Pt, have strong spin-orbit coupling by themselves, and can create a spin hall effect and thus also have a spin-orbit torque effect. In addition, the spin orbit torque is also found on the surface of the topological insulator, and the spin orbit coupling effect mainly comes from the characteristic non-energy gap dirac surface state of the topological insulator.
At present, the concept of spin orbit torque has shown great promise in the fields of magnetic memory, arithmetic, memory devices, and the like. In addition, the spin orbit torque has great application value in microwave oscillators and spin logic devices with low energy consumption. The spin orbit torque provides a new way for realizing the microwave oscillating circuit. Since the transmission frequency can be controlled by current, a spin-orbit-torque-based microwave oscillator generally has an ultra-wide frequency range. Therefore, spin orbit torque has great application potential in the fields of wireless communication and induction devices, such as space communication, high-speed radio frequency broadcasting, vehicle radar application, health safety field and the like.
Spin-orbit torque has many advantages, but its practical application still has many challenges. The most critical scientific problem is that the spin orbit torque and the perpendicular magnetic field are respectivelyIncompatibility of the switching of the anisotropy magnetization. The in-plane magnetic anisotropy material is difficult to further reduce to a nanometer scale, and is not beneficial to high-density device integration, and the magnetization reversal of the perpendicular magnetic anisotropy has the advantages of fast reversal and high integration, so the magnetization reversal of the perpendicular magnetic anisotropy is the mainstream choice for future application. At present, most researches on spin orbit torque related principles utilize anti-damping torque in a current generation plane to realize deterministic perpendicular magnetic anisotropy magnetization reversal, and at the moment, an external magnetic field parallel to the current is additionally applied to break the symmetry of a system or introduce the asymmetry of a structure to assist in reversal to realize the deterministic perpendicular magnetic anisotropy magnetization reversal. For this mechanism, the critical anti-damping torque needs to be satisfied
Here, the
Namely the reverse damping moment in the critical plane,
the ratio of the magnetic flux to the magnetic flux is,
is the perpendicular magnetic anisotropy field. The mechanism is the mainstream research direction of the current spin orbit torque, no matter the spin Hall effect of heavy metal, the Rashba-Edelstein effect of an interface or the surface state of a topological insulator, the magnetization reversal of the deterministic perpendicular magnetic anisotropy is realized through the in-plane anti-damping torque, and therefore, an external magnetic field or a complex structural design is needed to assist in the realization of the reversal.
In addition to utilizing the in-plane anti-damping torque, if the out-of-plane anti-damping torque of the spin current can be realized, the perpendicular magnetic anisotropy magnetization reversal without the assistance of an external magnetic field can be realized. However, the required symmetry conditions for realizing out-of-plane anti-damping torque are very strict, and the symmetry is not satisfactory for common spin orbit torque systems, namely heavy metals, the interfacial Rashba effect and topological insulatorsOut-of-plane anti-damping moment conditions. The specific form of the anti-damping moment satisfies
Here, the
In order to provide an anti-damping torque,
is the direction of the magnetization and is,
the polarization direction of the current spin or orbital magnetic moment. From this equation, it can be seen that to achieve the out-of-plane anti-damping moment, the out-of-plane must be achieved
. For the spin Hall effect of heavy metal, the Rashba-Edelstein effect of the interface or the surface state of a topological insulator, the spin (magnetic moment) polarization generated by the current is along the in-plane direction, i.e. the spin Hall effect is along the in-plane direction
Is in-plane, so in these systems the anti-damping moment is also in-plane. In fact, it is very difficult to achieve out-of-plane polarization by the Edelstein effect of electron spins, which is only possible in some very specific systems (e.g. topological insulators with warping effect). But the conditions for its implementation are often very harsh or require fine adjustments, making practical use difficult. Thus, the incompatibility of spin-orbit torque with perpendicular magnetic anisotropy magnetization switching presents challenges for its application.
In summary, three main current ways of realizing magnetization switching by using the current effect, namely, current-induced oersted field, spin transfer torque and spin orbit torque, face challenges in practical applications. The complexity of the device is increased by realizing magnetization switching by using an oersted field generated by current; the spin transfer torque has the problem that the read-write current paths are not separated, so that the durability of the device is poor; the spin orbit torque realizes the separation of read-write current paths, but the magnetization reversal of the perpendicular magnetic anisotropy is realized by the assistance of an external magnetic field.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a magnetization switching device based on a track transfer torque and an implementation method thereof, wherein the track transfer torque (OTT) is adopted to implement the perpendicular magnetic anisotropy magnetization switching, external magnetic field assistance or complex asymmetric structure design is not needed, and the advantages of spin-track torque read-write path separation, high efficiency and high speed switching are retained.
One object of the present invention is to propose a magnetization switching device based on a track transfer torque.
The magnetization switching device based on the track transfer torque comprises: the device comprises a substrate, an insulating medium layer, a source drain electrode, a measuring electrode, a heterojunction, a top gate and a back gate; forming an insulating medium layer on the front surface of the substrate; forming a back gate on the back surface of the substrate; forming a source drain electrode and a pair of measuring electrodes on the insulating medium layer, wherein the source drain electrode and the pair of measuring electrodes are parallel to each other, the source drain electrode and the pair of measuring electrodes are perpendicular to each other, and the source drain electrode and the pair of measuring electrodes form a cross-shaped bottom electrode; forming a heterojunction on the bottom electrode, wherein the heterojunction comprises a two-dimensional layered second-order nonlinear Hall effect layer and a perpendicular magnetic anisotropic free ferromagnetic layer, the two-dimensional layered second-order nonlinear Hall effect layer adopts a two-dimensional layered material with a second-order nonlinear Hall effect, the two-dimensional layered material with the second-order nonlinear Hall effect has a periodic lattice potential, electrons in the two-dimensional layered second-order nonlinear Hall effect layer play a role in a quasi-particle mode, namely bloch electrons which form a bloch wave packet, and the bloch wave packet has angular momentum rotating around the bloch wave packet, so that the electrons have an extra orbital magnetic moment besides a spinning magnetic moment, the orbital magnetic moment is limited and arranged in an out-of-plane direction due to two-dimensional dimensions, and the two-dimensional layered second-order nonlinear Hall effect layer belongs to a two-dimensional system with a nonzero Belley curvature dipole moment; the heterojunction is in contact with each of the bottom electrodes; forming a top gate on the heterojunction, the top gate comprising a bottom insulating layer and a top electrode on the insulating layer; the insulating layer of the top gate is required to completely cover the heterojunction to realize packaging; the top electrode of the top gate covers the channel of the heterojunction, i.e. the top electrode covers the path of current flowing through the heterojunction; the back gate is connected to the positive electrode of the first direct-current voltage source, the negative electrode of the first direct-current voltage source is grounded, the top electrode of the top gate is connected to the positive electrode of the second direct-current voltage source, and the negative electrode of the second direct-current voltage source is grounded; the source electrode is connected to the anode of the current source, the cathode of the current source is grounded, and the drain electrode is grounded; the pair of measuring electrodes are respectively connected to the positive electrode and the negative electrode of the voltmeter;
the first DC voltage source applies a back gate voltage VBSo that a potential difference is formed between the back gate and the lower surface of the heterojunction, and a top gate voltage V is applied from a second DC voltage sourceTForming a potential difference between the top electrode of the top gate and the upper surface of the heterojunction; the carrier concentration of the heterojunction is adjusted through the field effect of the back gate and the top gate, and the non-uniform charge distribution is respectively introduced to the upper surface and the lower surface of the heterojunction, so that an out-of-plane electric field vertical to the surface of the heterojunction is caused in the heterojunction, and the voltage V is obtained through the back gateBAnd a top gate voltage VTAdjusting the carrier concentration of the heterojunction and an external surface electric field to enable the two-dimensional layered second-order nonlinear Hall effect layer to have the maximum Belleville curvature dipole moment; a current source passes through a source drain electrode to direct current write current IpThe polarization of the out-of-plane orbital magnetic moment is generated under the combined action of the Belley curvature dipole moment of the two-dimensional layered second-order nonlinear Hall effect layer and the writing current, the polarization direction of the orbital magnetic moment is related to the direction of the writing current, the polarization of the orbital magnetic moment generates an out-of-plane anti-damping moment effect, the out-of-plane anti-damping moment based on the orbital magnetic moment is called a track transfer moment, the out-of-plane anti-damping moment is simultaneously in a linear relation with the writing current and the Belley curvature dipole moment, and the generated out-of-plane anti-damping moment is maximum when the direction of the writing current is parallel to the Belley curvature dipole moment; the magnetization reversal of the perpendicular magnetic anisotropy free ferromagnetic layer can be realized without additional magnetic field assistance under the effect of the out-of-plane anti-damping moment, namely, the perpendicular magnetic anisotropy magnetization reversal based on the track transfer moment is realizedRotating; removing the write current, wherein the perpendicular magnetic anisotropy free ferromagnetic layer keeps the changed magnetization state after the write current is removed, so that the perpendicular magnetic anisotropy free ferromagnetic layer has non-volatility; the current source is connected with a direct current reading current i through the source electrode and the drain electrode, and the voltmeter is used for obtaining the Hall resistance of the heterojunction through the measuring electrode, so that the magnetization state of the perpendicular magnetic anisotropy free ferromagnetic layer is obtained; changing the direction of the write current, i.e. passing the write current-I from the current source through the source-drain electrodespThe polarization direction of the orbital magnetic moment is reversed, and the reversed orbital transfer moment is realized, so that the magnetization of the perpendicular magnetic anisotropy free ferromagnetic layer is reversed.
The nonlinear hall effect means that the measured hall voltage is proportional to the square of the drive current under the condition that time reversal symmetry is satisfied. In general, the measurement is carried out by using a standard phase-locking technology, wherein the switching frequency is
Then measuring the frequency of the alternating current of
If the non-zero Hall voltage can be measured, and the amplitude of the Hall voltage and the amplitude of the driving current satisfy the quadratic dependence relationship, the nonlinear Hall effect is realized; perpendicular magnetic anisotropy the free ferromagnetic layer employs a layered ferromagnetic material having perpendicular magnetic anisotropy.
In a two-dimensional system, the spin magnetic moments can still be aligned in-plane due to two-dimensional planar constraints, but the orbital magnetic moments are aligned in the out-of-plane direction due to dimensional constraints. The current-induced orbital magnetic moment polarization generates out-of-plane anti-damping torque, and the deterministic perpendicular magnetic anisotropy magnetization reversal can be realized without the assistance of an additional magnetic field. This out-of-plane anti-damping moment based on the orbital magnetic moment is in principle completely different from the spin-orbit moment, which is due to the polarization of the spins, and therefore this out-of-plane anti-damping moment based on the orbital magnetic moment is referred to as the orbital transfer moment by the present invention. Furthermore, fixThe orbital magnetic moment of a bloch electron in a body is closely related to the geometric phase curvature, the belief curvature, of its wave function. When particle-hole symmetry is present, the orbital magnetic moment and the bery curvature exhibit a simple proportional relationship. Achieving current-induced orbital magnetic moment polarization is equivalent to achieving current-induced bery curvature polarization. The concept of bery curvature dipole moment is just as useful to describe the polarization effect of bery curvature under current. Therefore, for a two-dimensional system with a nonzero Belgium curvature dipole moment, current-induced out-of-plane orbital magnetic moment polarization can be realized, and therefore the perpendicular magnetic anisotropy magnetization reversal based on the orbital transfer moment effect is realized. The system with non-zero Belgium curvature dipole moment D can generate macroscopic orbital magnetization under the action of an electric field E
Wherein
Is a unit vector oriented in the out-of-plane direction. Under the action of the orbital magnetization M, an out-of-plane anti-damping torque, i.e. an orbital transfer torque, can be achieved. One typical transport characteristic of the bery curvature dipole moment is the second-order nonlinear hall effect.
The substrate is made of conductive material, such as silicon substrate doped with heavy electrons.
The top electrode, the back gate electrode, the source drain electrode and the measuring electrode of the top gate are all made of conductive metal, such as gold.
The two-dimensional layered second-order nonlinear Hall effect layer adopts double-layer tungsten ditelluride WTE2Strain double-layer graphene, single-layer tungsten ditelluride WSe with uniaxial strain2And Weyl semimetal (TaIrTe tantalum iridium tellurium with thickness of 50-100 nm) with broken symmetry of space inversion4Or molybdenum ditelluride MoTe with the thickness of 4-8 nm2) One of (1); the vertical magnetic anisotropy layered ferromagnetic layer adopts a thin Fe-Ge-Te-Fe layer3GeTe2(thickness 4-10 nm), chromium ditelluride CrTe2(thickness 2-8 nm) and chromium triiodide CrI3(thickness 2-8 nm and odd number layer).
Write current IpA critical current I greater than that in the heterojunction is required to enable magnetization switching of perpendicular magnetic anisotropycIn different embodiments, IcThe values are different, typically in the order of mA. The read current I is much smaller than the critical current IcIs usually taken
Magnitude.
Another object of the present invention is to provide a method for implementing a magnetization switching device based on a track transfer torque.
The invention discloses a method for realizing a magnetization switching device based on track transfer torque, which comprises the following steps:
1) preparing a device:
a) providing a substrate, and forming an insulating medium layer on the front surface of the substrate;
b) forming a back gate on the back surface of the substrate;
c) forming a source-drain electrode and a pair of measuring electrodes on the insulating medium layer by utilizing a photoetching technology and a film coating technology (including electron beam evaporation or magnetron sputtering and the like), wherein the source-drain electrode is parallel to the measuring electrode, the measuring electrodes are parallel to each other, the source-drain electrode is perpendicular to the measuring electrodes, and the source-drain electrode and the measuring electrodes form a cross-shaped bottom electrode;
d) obtaining a heterojunction formed by a two-dimensional layered second-order nonlinear Hall effect layer and a perpendicular magnetic anisotropy free ferromagnetic layer by using a single crystal growth method, a mechanical stripping method and a dry transfer method, and transferring the heterojunction onto a bottom electrode; the two-dimensional layered second-order nonlinear Hall effect layer is a two-dimensional layered material with a second-order nonlinear Hall effect, the two-dimensional layered material with the second-order nonlinear Hall effect has a periodic lattice potential, electrons in the two-dimensional layered second-order nonlinear Hall effect layer play a role in a quasi-particle mode, namely bloch electrons, the bloch electrons form a bloch wave packet, and the bloch wave packet has angular momentum rotating around the bloch wave packet, so that the electrons have an extra orbital magnetic moment besides a spinning magnetic moment, the orbital magnetic moment is limited and arranged in an out-of-plane direction due to two-dimensional dimensions, and the two-dimensional layered second-order nonlinear Hall effect layer belongs to a two-dimensional system with a nonzero Belley curvature dipole moment; the heterojunction is in contact with each of the bottom electrodes;
e) forming a top gate on the heterojunction by transfer, photolithography and coating techniques, the top gate comprising a bottom insulating layer and a top electrode on the insulating layer; the insulating layer of the top gate is required to completely cover the heterojunction to realize packaging; the top electrode of the top gate covers the channel of the heterojunction, i.e. the top electrode covers the path of current flowing through the heterojunction;
f) the back gate is connected to the positive electrode of the first direct-current voltage source, the negative electrode of the first direct-current voltage source is grounded, the top gate is connected to the positive electrode of the second direct-current voltage source, and the negative electrode of the second direct-current voltage source is grounded; the source electrode is connected to the anode of the current source, the cathode of the current source is grounded, and the drain electrode is grounded; the pair of measuring electrodes are respectively connected to the positive electrode and the negative electrode of the voltmeter;
2) the first DC voltage source applies a back gate voltage VBSo that a potential difference is formed between the back gate and the lower surface of the heterojunction, and a top gate voltage is applied by the second direct current voltage source so that a potential difference is formed between the top electrode of the top gate and the upper surface of the heterojunction; the carrier concentration of the heterojunction is adjusted through the field effect of the back gate and the top gate, and non-uniform charge distribution is respectively introduced to the upper surface and the lower surface of the heterojunction, so that an out-of-plane electric field perpendicular to the surface of the heterojunction is caused on the surface of the heterojunction; through the back gate voltage VBAnd a top gate voltage VTAdjusting the carrier concentration of the heterojunction and an external surface electric field to enable the two-dimensional layered second-order nonlinear Hall effect layer to have the maximum Belleville curvature dipole moment;
3) a current source passes through a source drain electrode to direct current write current IpThe polarization of the track magnetic moment is generated under the combined action of the Belley curvature dipole moment of the two-dimensional layered second-order nonlinear Hall effect layer and the writing current, the polarization direction of the track magnetic moment is related to the direction of the writing current, the polarization of the track magnetic moment generates an out-of-plane anti-damping moment effect, the out-of-plane anti-damping moment based on the track magnetic moment is called a track transfer moment, the out-of-plane anti-damping moment is simultaneously in a linear relation with the writing current and the Belley curvature dipole moment, and when the direction of the writing current is parallel to the Belley curvature dipole momentThe out-of-plane anti-damping moment generated is maximum; the magnetization reversal of the perpendicular magnetic anisotropy free ferromagnetic layer can be realized without the assistance of an additional magnetic field under the effect of the out-of-plane anti-damping moment, namely, the perpendicular magnetic anisotropy magnetization reversal based on the track transfer moment is realized;
4) removing the write current, wherein the perpendicular magnetic anisotropy free ferromagnetic layer keeps the changed magnetization state after the write current is removed, so that the perpendicular magnetic anisotropy free ferromagnetic layer has non-volatility;
5) the current source is connected with a direct current reading current i through the source electrode and the drain electrode, and the voltmeter is used for obtaining the Hall resistance of the heterojunction through the measuring electrode, so that the magnetization state of the perpendicular magnetic anisotropy free ferromagnetic layer is obtained;
6) the direction of the write current is changed to reverse the polarization direction of the orbital magnetic moment, thereby realizing a reverse orbital transfer moment and reversing the magnetization of the perpendicular magnetic anisotropy free ferromagnetic layer.
In step d) of step 1), a two-dimensional layered source material block with a second-order nonlinear hall effect and a perpendicular magnetic anisotropy free ferromagnetic source material block with a second-order nonlinear hall effect are respectively grown in a tube furnace by using a single crystal growth method (such as chemical vapor deposition, seed crystal temperature reduction, chemical vapor transport and the like), then a two-dimensional layered thin layer material with a second-order nonlinear hall effect and a perpendicular magnetic anisotropy free ferromagnetic thin layer material are respectively stripped from the two-dimensional layered source material block with the second-order nonlinear hall effect and the perpendicular magnetic anisotropy free ferromagnetic source material block with the perpendicular magnetic anisotropy by using a mechanical stripping method, the two-dimensional layered thin layer material with the second-order nonlinear hall effect is transferred to a first transition insulating layer on a first transition substrate to form a two-dimensional layered second-order nonlinear hall effect layer, and the perpendicular magnetic anisotropy free ferromagnetic thin layer material is transferred to a second transition insulating layer on a second transition substrate to form a perpendicular magnetic anisotropy free ferromagnetic thin layer A magnetic layer; and obtaining a heterojunction formed by the two-dimensional layered second-order nonlinear Hall effect layer and the perpendicular magnetic anisotropy free ferromagnetic layer by using a dry transfer method.
In step 2), the magnitude of Belgium curvature dipole moment is measuredThe second-order nonlinear Hall effect in the quantum heterojunction is determined, and the frequency is introduced through the source and drain electrodes
With a fixed amplitude of the alternating current ofacMeasuring the frequency by measuring electrodes of
Reading the second order frequency Hall voltage, and reading the amplitude V of the second order frequency Hall voltageacWhen adjusting the top gate voltage VTAnd back gate voltage VBSo that the amplitude V of the second order frequency Hall voltageacAt maximum, the dipole moment corresponding to the Belleville curvature is largest. Frequency of
17-100 Hz, usually 17.777 Hz to avoid mains interference. Amplitude I of the alternating currentacTaking 0.1 mA-0.5 mA. Top gate voltage VTAnd back gate voltage VBusually-10V-10V.
In step 3), the current I is writtenpGreater than critical current I capable of realizing magnetization reversal of perpendicular magnetic anisotropy in heterojunctioncIn different embodiments, IcThe values are different, typically in the order of mA.
The invention has the advantages that:
the present invention provides a new principle to achieve magnetization switching of perpendicular magnetic anisotropy, i.e. the track transfer torque. The current three main flow modes, namely the Oersted effect of current, spin transfer torque and spin orbit torque, realize magnetization reversal based on the electron spin degree of freedom, and the orbit transfer torque is based on the electron orbit magnetic moment degree of freedom; the track transfer torque can simultaneously realize simple device structure, separable read-write paths (combined with magnetic tunnel junctions) and no need of auxiliary turnover of an external magnetic field, namely, the advantages of the three main flow modes are absorbed and the defects are avoided; the track transfer torque realizes the magnetization reversal of the perpendicular magnetic anisotropy and has the advantages of high efficiency, high speed and high integration; in addition, due to perpendicular magnetic anisotropy based on track transfer torqueThe sexual magnetization reversal utilizes the out-of-plane anti-damping moment, and the out-of-critical-plane anti-damping moment is satisfied
Here, the
Namely the critical out-of-plane anti-damping moment,
is the Gilbert damping parameter, which is typically of the order of 0.01, satisfies the critical in-plane anti-damping moment described above
Therefore, theoretically, the critical current required by the track transfer torque to realize magnetization reversal is smaller than that of the three main flow modes, so that the power consumption of the device can be greatly reduced.
Drawings
FIG. 1 is a schematic diagram of one embodiment of a track transfer torque based magnetization switching device of the present invention;
FIG. 2 is a schematic diagram of a manufacturing process of one embodiment of the magnetization switching device based on track transfer torque of the present invention.
Detailed Description
The invention will be further elucidated by means of specific embodiments in the following with reference to the drawing.
As shown in fig. 1, the magnetization switching device based on the track transfer torque of the present embodiment includes: the device comprises a substrate 1, an insulating medium layer 2, a source drain electrode, a measuring electrode, a heterojunction, a top gate and a back gate; wherein, an insulating medium layer 2 is formed on the front surface of the substrate; forming a back gate on the back surface of the substrate; forming a source drain electrode and a pair of measuring electrodes on the insulating medium layer, wherein the source drain electrode and the measuring electrode are parallel to each other, the measuring electrodes are parallel to each other, the source drain electrode and the measuring electrode are perpendicular to each other, and the source drain electrode and the pair of measuring electrodes form a cross-shaped bottom electrode 3; forming a heterojunction on the bottom electrode, wherein the heterojunction comprises a two-dimensional layered second-order nonlinear Hall effect layer 4 and a perpendicular magnetic anisotropy free ferromagnetic layer 5, the two-dimensional layered second-order nonlinear Hall effect layer adopts a two-dimensional layered material with a second-order nonlinear Hall effect, the two-dimensional layered material with the second-order nonlinear Hall effect has a periodic lattice potential, electrons in the two-dimensional layered second-order nonlinear Hall effect layer play a role in a quasi-particle mode, namely Bloch electrons, and the Bloch electrons form a Bloch wave packet; the bloch wave packet has angular momentum rotating around itself, so that the electron has an extra orbital magnetic moment in addition to the spin magnetic moment; the two-dimensional layered second-order nonlinear Hall effect layer belongs to a two-dimensional system with nonzero Belgium curvature dipole moment; the heterojunction is in contact with each of the bottom electrodes; forming a top gate over the heterojunction, the top gate comprising a bottom insulating layer 6 and a top electrode 7 on the insulating layer; the insulating layer of the top gate is required to completely cover the heterojunction to realize packaging; the top electrode of the top gate covers the channel of the heterojunction, i.e. the top electrode covers the path of current flowing through the heterojunction; the back gate is connected to the positive electrode of the first direct-current voltage source, the negative electrode of the first direct-current voltage source is grounded, the top electrode of the top gate is connected to the positive electrode of the second direct-current voltage source, and the negative electrode of the second direct-current voltage source is grounded; the source electrode is connected to the anode of the current source, the cathode of the current source is grounded, and the drain electrode is grounded; the pair of measuring electrodes are respectively connected to the positive electrode and the negative electrode of the voltmeter.
In the embodiment, the substrate is a silicon substrate doped with heavy electrons; the insulating medium layer is made of SiO with thickness of 285 nm2(ii) a The source electrode, the drain electrode and the measuring electrode adopt Ti/Au with the thickness of 2nm/8 nm; the top electrode and the back gate electrode of the top gate adopt Ti/Au with the thickness of 5/45 nm; the insulating layer in the top gate adopts h-BN (the thickness is 20-30 nm); MoTe is adopted as the two-dimensional layered second-order nonlinear Hall effect layer2(thickness 4-8 nm); the perpendicular magnetic anisotropy laminated ferromagnetic layer adopts thin layer Fe3GeTe2(thickness 4-10 nm).
The invention discloses a method for realizing a magnetization switching device based on track transfer torque, which comprises the following steps:
1) device preparation, as shown in fig. 2:
a) providing a substrate 1 of silicon material, and forming an insulating medium layer 2 on the front surface of the substrate;
b) forming a back gate on the back surface of the substrate;
c) forming a source-drain electrode and a pair of measuring electrodes on the insulating medium layer by using standard electron beam exposure and electron beam coating technologies, wherein the source-drain electrode is parallel to the measuring electrode, the measuring electrode is parallel to the source-drain electrode, the source-drain electrode is perpendicular to the measuring electrode, and the source-drain electrode and the pair of measuring electrodes form a cross-shaped bottom electrode 3 as shown in fig. 2 (a);
d) respectively growing a two-dimensional layered source material block with a second-order nonlinear Hall effect and a perpendicular magnetic anisotropy free ferromagnetic source material block in a tube furnace by using a chemical vapor deposition method, respectively stripping the two-dimensional layered source material block with the second-order nonlinear Hall effect and the perpendicular magnetic anisotropy free ferromagnetic source material block with the second-order nonlinear Hall effect by using a polydimethylsiloxane 8 (PDMS) assisted mechanical stripping method to respectively obtain a two-dimensional layered thin layer material with the second-order nonlinear Hall effect and a perpendicular magnetic anisotropy free ferromagnetic thin layer material, as shown in FIG. 2 (b), specifically, placing the source material block to be stripped on a piece of PDMS, repeatedly using another piece of PDMS for carrying out adhesion to obtain the thin layer material, forming a first transition insulating layer on a first transition substrate (the material is silicon), and forming a second insulating layer on a second transition substrate, then transferring the two-dimensional layered thin-layer material with the second-order nonlinear Hall effect and the perpendicular magnetic anisotropy free ferromagnetic thin-layer material to a first transition insulating layer and a second transition insulating layer respectively to form a two-dimensional layered second-order nonlinear Hall effect layer and a perpendicular magnetic anisotropy free ferromagnetic material thin layer respectively; adhering a vertical magnetic anisotropy free ferromagnetic material thin layer and a two-dimensional layered second-order nonlinear hall effect layer from the second transition insulating layer and the first transition insulating layer in sequence by using a Polycarbonate (PC) film 9 by using a dry transfer method to form a heterojunction, and transferring the heterojunction onto the bottom electrode, as shown in fig. 2 (c) and 2 (d); the two-dimensional layered second-order nonlinear Hall effect layer is a two-dimensional layered material with a second-order nonlinear Hall effect, the two-dimensional layered material with the second-order nonlinear Hall effect has a periodic lattice potential, electrons in the two-dimensional layered material act in a quasi-particle form, namely bloch electrons, and the bloch electrons form a bloch wave packet; the Bloch wave packet has angular momentum rotating around the Bloch wave packet, so that electrons have an extra orbital magnetic moment besides a spinning magnetic moment, the orbital magnetic moment is limited to be arranged in an out-of-plane direction due to two-dimensional dimensions, and the out-of-plane direction is perpendicular to the surface of the two-dimensional layered second-order nonlinear Hall effect layer and is perpendicular to the surface upwards or downwards; the two-dimensional layered second-order nonlinear Hall effect layer belongs to a two-dimensional system with nonzero Belgium curvature dipole moment; the heterojunction is in contact with each of the bottom electrodes;
e) forming a top gate insulating layer 6 on the heterojunction by using a dry transfer technique; the insulating layer of the top gate is required to completely cover the heterojunction to realize packaging; forming a top electrode 7 of the top gate on the insulating layer using standard electron beam exposure and electron beam coating techniques, as shown in fig. 2 (e); the top electrode of the top gate covers the channel of the heterojunction, i.e. the top electrode covers the path of current flowing through the heterojunction;
f) the back gate is connected to the positive electrode of the first direct-current voltage source, the negative electrode of the first direct-current voltage source is grounded, the top electrode of the top gate is connected to the positive electrode of the second direct-current voltage source, and the negative electrode of the second direct-current voltage source is grounded; the source electrode is connected to the anode of the current source, the cathode of the current source is grounded, and the drain electrode is grounded; the pair of measuring electrodes are respectively connected to the positive electrode and the negative electrode of the voltmeter;
2) the first DC voltage source applies a back gate voltage VB(range-6V-6V) so that a potential difference is formed between the back gate and the lower surface of the heterojunction, and the second DC voltage source applies a top gate voltage VT(in the range-6V) such that a potential difference is formed between the top electrode of the top gate and the upper surface of the heterojunction; the heterojunction is a metal system and has strong electrostatic shielding, so that the top gate can only effectively adjust the upper surface of the heterojunction, and the back gate can only effectively adjust the lower surface of the heterojunction; the carrier concentration of the heterojunction is adjusted through the field effect of the back gate and the top gate, and non-uniform charge distribution is respectively introduced to the upper surface and the lower surface of the heterojunction, so that an out-of-plane electric field perpendicular to the surface of the heterojunction is caused on the surface of the heterojunction; by carrying on the backGrid voltage VBAnd a top gate voltage VTAdjusting the carrier concentration of the heterojunction and an external surface electric field to enable the two-dimensional layered second-order nonlinear Hall effect layer to have the maximum Belleville curvature dipole moment; the size of the Belgium curvature dipole moment is determined by measuring the second-order nonlinear Hall effect in the heterojunction, and the frequency is introduced through the source and drain electrodes
17.777 Hz alternating current with fixed amplitude Iac=0.1 mA, measured at a frequency of measurement by measuring electrodes
Reading the second-order frequency Hall voltage and reading the amplitude V thereofacWhen adjusting the top gate voltage VTAnd back gate voltage VBSo that VacAt maximum, i.e., the dipole moment corresponding to the Belleville curvature is maximum;
3) a current source passes through a source drain electrode to direct current write current Ip=8-10 mA, write current IpGreater than critical current I capable of realizing magnetization reversal of perpendicular magnetic anisotropy in heterojunctionc(ii) a Polarization of the track magnetic moment is generated under the combined action of the Belley curvature dipole moment of the two-dimensional layered second-order nonlinear Hall effect layer and the writing current, and the polarization direction of the track magnetic moment is related to the direction of the writing current, namely the direction of the current is opposite to the polarization direction of the track magnetic moment, and the direction is changed from upward to downward or from downward to upward; the polarization of the track magnetic moment generates an out-of-plane anti-damping moment effect, the out-of-plane anti-damping moment based on the track magnetic moment is called a track transfer moment, the out-of-plane anti-damping moment has a linear relation with the write current and the Belley curvature dipole moment, and when the direction of the write current is parallel to the Belley curvature dipole moment, the generated out-of-plane anti-damping moment is maximum; the magnetization reversal of the perpendicular magnetic anisotropy free ferromagnetic layer can be realized without the assistance of an additional magnetic field under the effect of the out-of-plane anti-damping moment, namely, the perpendicular magnetic anisotropy magnetization reversal based on the track transfer moment is realized;
4) removing the write current, wherein the perpendicular magnetic anisotropy free ferromagnetic layer keeps the changed magnetization state after the write current is removed, so that the perpendicular magnetic anisotropy free ferromagnetic layer has non-volatility;
5) a current source leads in direct current reading current i =10 through a source drain electrode
The voltmeter obtains the Hall resistance of the heterojunction through the measuring electrode, so that the magnetization state of the perpendicular magnetic anisotropy free ferromagnetic layer is obtained;
6) the direction of the write current is changed to reverse the polarization direction of the orbital magnetic moment, thereby realizing a reverse orbital transfer moment and reversing the magnetization of the perpendicular magnetic anisotropy free ferromagnetic layer.
Finally, it is noted that the disclosed embodiments are intended to aid in further understanding of the invention, but those skilled in the art will appreciate that: various substitutions and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the invention should not be limited to the embodiments disclosed, but the scope of the invention is defined by the appended claims.
Claims (10)
1. A track transfer torque based magnetization switching device, comprising: the device comprises a substrate, an insulating medium layer, a source drain electrode, a measuring electrode, a heterojunction, a top gate and a back gate; forming an insulating medium layer on the front surface of the substrate; forming a back gate on the back surface of the substrate; forming a source-drain electrode and a pair of measuring electrodes on the insulating medium layer, wherein the source-drain electrode is aligned with the source-drain electrode, and the pair of measuring electrodes is aligned with each other; forming a heterojunction on the bottom electrode, wherein the heterojunction comprises a two-dimensional layered second-order nonlinear Hall effect layer and a perpendicular magnetic anisotropic free ferromagnetic layer, the two-dimensional layered second-order nonlinear Hall effect layer adopts a two-dimensional layered material with a second-order nonlinear Hall effect, the two-dimensional layered material with the second-order nonlinear Hall effect has a periodic lattice potential, electrons in the two-dimensional layered second-order nonlinear Hall effect layer play a role in a quasi-particle mode, namely bloch electrons which form a bloch wave packet, and the bloch wave packet has angular momentum rotating around the bloch wave packet, so that the electrons have an extra orbital magnetic moment besides a spinning magnetic moment, the orbital magnetic moment is limited and arranged in an out-of-plane direction due to two-dimensional dimensions, and the two-dimensional layered second-order nonlinear Hall effect layer belongs to a two-dimensional system with a nonzero Belley curvature dipole moment; the heterojunction is in contact with each of the bottom electrodes; forming a top gate on the heterojunction, the top gate comprising a bottom insulating layer and a top electrode on the insulating layer; the insulating layer of the top gate is required to completely cover the heterojunction to realize packaging; the top electrode of the top gate covers the channel of the heterojunction, i.e. the top electrode covers the path of current flowing through the heterojunction; the back gate is connected to the positive electrode of the first direct-current voltage source, the negative electrode of the first direct-current voltage source is grounded, the top electrode of the top gate is connected to the positive electrode of the second direct-current voltage source, and the negative electrode of the second direct-current voltage source is grounded; the source electrode is connected to the anode of the current source, the cathode of the current source is grounded, and the drain electrode is grounded; the pair of measuring electrodes are respectively connected to the positive electrode and the negative electrode of the voltmeter;
the first DC voltage source applies a back gate voltage VBSo that a potential difference is formed between the back gate and the lower surface of the heterojunction, and a top gate voltage V is applied from a second DC voltage sourceTForming a potential difference between the top electrode of the top gate and the upper surface of the heterojunction; the carrier concentration of the heterojunction is adjusted through the field effect of the back gate and the top gate, and the non-uniform charge distribution is respectively introduced to the upper surface and the lower surface of the heterojunction, so that an out-of-plane electric field vertical to the surface of the heterojunction is caused in the heterojunction, and the voltage V is obtained through the back gateBAnd a top gate voltage VTAdjusting the carrier concentration of the heterojunction and an external surface electric field to enable the two-dimensional layered second-order nonlinear Hall effect layer to have the maximum Belleville curvature dipole moment; a current source passes through a source drain electrode to direct current write current IpThe polarization of the out-of-plane orbital magnetic moment is generated under the combined action of the Belley curvature dipole moment of the two-dimensional layered second-order nonlinear Hall effect layer and the writing current, the polarization direction of the orbital magnetic moment is related to the direction of the writing current, the polarization of the orbital magnetic moment generates an out-of-plane anti-damping moment effect, the out-of-plane anti-damping moment based on the orbital magnetic moment is called an orbital transfer moment, and the out-of-plane anti-damping moment is called an orbital transfer momentMeanwhile, the linear relation is formed between the write current and the Belleville curvature dipole moment, and when the direction of the write current is parallel to the Belleville curvature dipole moment, the generated out-of-plane anti-damping moment is the largest; the magnetization reversal of the perpendicular magnetic anisotropy free ferromagnetic layer can be realized without the assistance of an additional magnetic field under the effect of the out-of-plane anti-damping moment, namely, the perpendicular magnetic anisotropy magnetization reversal based on the track transfer moment is realized; removing the write current, wherein the perpendicular magnetic anisotropy free ferromagnetic layer keeps the changed magnetization state after the write current is removed, so that the perpendicular magnetic anisotropy free ferromagnetic layer has non-volatility; the current source is connected with a direct current reading current i through the source electrode and the drain electrode, and the voltmeter is used for obtaining the Hall resistance of the heterojunction through the measuring electrode, so that the magnetization state of the perpendicular magnetic anisotropy free ferromagnetic layer is obtained; changing the direction of the write current, i.e. passing the write current-I from the current source through the source-drain electrodespThe polarization direction of the orbital magnetic moment is reversed, and the reversed orbital transfer moment is realized, so that the magnetization of the perpendicular magnetic anisotropy free ferromagnetic layer is reversed.
2. A track transfer torque based magnetization switching device according to claim 1, characterized in that the substrate is of an electrically conductive material.
3. The track transfer torque-based magnetization switching device according to claim 1, wherein the top electrode, the back gate electrode, the source and drain electrodes, and the measurement electrode of the top gate are made of conductive metal.
4. The track-transfer-torque-based magnetization switching device according to claim 1, wherein the two-dimensional layered second-order nonlinear hall effect layer employs a double-layer tungsten ditelluride WTe2Strain double-layer graphene, single-layer tungsten ditelluride WSe with uniaxial strain2And spatially inverting one of the symmetry-breaking peril semimetals; the vertical magnetic anisotropy layered ferromagnetic layer adopts a thin iron-germanium-tellurium (Fe)3GeTe2Chromium ditelluride CrTe2And chromium triiodide CrI3One kind of (1).
5. A track transfer torque based magnetization switching device according to claim 1, characterized in that the write current is larger than the critical current in the heterojunction enabling a perpendicular magnetic anisotropy magnetization switching.
6. The track transfer torque based magnetization switching device according to claim 1, wherein the read current is much smaller than a critical current in a heterojunction that enables perpendicular magnetic anisotropy magnetization switching.
7. A method for implementing a magnetization switching device based on a track transfer torque according to claim 1, characterized in that it comprises the following steps:
1) preparing a device:
a) providing a substrate, and forming an insulating medium layer on the front surface of the substrate;
b) forming a back gate on the back surface of the substrate;
c) forming a source-drain electrode and a pair of measuring electrodes on the insulating medium layer by utilizing a photoetching technology and a film coating technology, wherein the source-drain electrode is aligned with the source-drain electrode, and the pair of measuring electrodes is aligned with each other;
d) obtaining a heterojunction formed by a two-dimensional layered second-order nonlinear Hall effect layer and a perpendicular magnetic anisotropy free ferromagnetic layer by using a single crystal growth method, a mechanical stripping method and a dry transfer method, and transferring the heterojunction onto a bottom electrode; the two-dimensional layered second-order nonlinear Hall effect layer is a two-dimensional layered material with a second-order nonlinear Hall effect, the two-dimensional layered material with the second-order nonlinear Hall effect has a periodic lattice potential, electrons in the two-dimensional layered second-order nonlinear Hall effect layer play a role in a quasi-particle mode, namely bloch electrons, the bloch electrons form a bloch wave packet, and the bloch wave packet has angular momentum rotating around the bloch wave packet, so that the electrons have an extra orbital magnetic moment besides a spinning magnetic moment, the orbital magnetic moment is limited and arranged in an out-of-plane direction due to two-dimensional dimensions, and the two-dimensional layered second-order nonlinear Hall effect layer belongs to a two-dimensional system with a nonzero Belley curvature dipole moment; the heterojunction is in contact with each of the bottom electrodes;
e) forming a top gate on the heterojunction by transfer, photolithography and coating techniques, the top gate comprising a bottom insulating layer and a top electrode on the insulating layer; the insulating layer of the top gate is required to completely cover the heterojunction to realize packaging; the top electrode of the top gate covers the channel of the heterojunction, i.e. the top electrode covers the path of current flowing through the heterojunction;
f) the back gate is connected to the positive electrode of the first direct-current voltage source, the negative electrode of the first direct-current voltage source is grounded, the top gate is connected to the positive electrode of the second direct-current voltage source, and the negative electrode of the second direct-current voltage source is grounded; the source electrode is connected to the anode of the current source, the cathode of the current source is grounded, and the drain electrode is grounded; the pair of measuring electrodes are respectively connected to the positive electrode and the negative electrode of the voltmeter;
2) the first DC voltage source applies a back gate voltage VBSo that a potential difference is formed between the back gate and the lower surface of the heterojunction, and a top gate voltage is applied by the second direct current voltage source so that a potential difference is formed between the top electrode of the top gate and the upper surface of the heterojunction; the carrier concentration of the heterojunction is adjusted through the field effect of the back gate and the top gate, and non-uniform charge distribution is respectively introduced to the upper surface and the lower surface of the heterojunction, so that an out-of-plane electric field perpendicular to the surface of the heterojunction is caused on the surface of the heterojunction; through the back gate voltage VBAnd a top gate voltage VTAdjusting the carrier concentration of the heterojunction and an external surface electric field to enable the two-dimensional layered second-order nonlinear Hall effect layer to have the maximum Belleville curvature dipole moment;
3) a current source passes through a source drain electrode to direct current write current IpThe polarization of the track magnetic moment is generated under the combined action of the Belley curvature dipole moment of the two-dimensional layered second-order nonlinear Hall effect layer and the writing current, the polarization direction of the track magnetic moment is related to the direction of the writing current, the polarization of the track magnetic moment generates an out-of-plane anti-damping moment effect, the out-of-plane anti-damping moment based on the track magnetic moment is called a track transfer moment, the out-of-plane anti-damping moment is simultaneously in a linear relation with the writing current and the Belley curvature dipole moment, and when the direction of the writing current is parallel to the Belley curvature dipole moment, the generated out-of-plane anti-damping moment is maximum; out-of-plane anti-damping moment effectThe magnetization reversal of the perpendicular magnetic anisotropy free ferromagnetic layer can be realized without the assistance of an additional magnetic field, namely, the perpendicular magnetic anisotropy magnetization reversal based on the track transfer torque is realized;
4) removing the write current, wherein the perpendicular magnetic anisotropy free ferromagnetic layer keeps the changed magnetization state after the write current is removed, so that the perpendicular magnetic anisotropy free ferromagnetic layer has non-volatility;
5) the current source is connected with a direct current reading current i through the source electrode and the drain electrode, and the voltmeter is used for obtaining the Hall resistance of the heterojunction through the measuring electrode, so that the magnetization state of the perpendicular magnetic anisotropy free ferromagnetic layer is obtained;
6) the direction of the write current is changed to reverse the polarization direction of the orbital magnetic moment, thereby realizing a reverse orbital transfer moment and reversing the magnetization of the perpendicular magnetic anisotropy free ferromagnetic layer.
8. The method of claim 7, wherein in step d) of step 1), two-dimensional layered source material blocks with second-order nonlinear Hall effect and perpendicular magnetic anisotropy free ferromagnetic source material blocks are respectively grown in a tubular furnace by a single crystal growth method, then, a two-dimensional layered thin-layer material with a second-order nonlinear Hall effect and a perpendicular magnetic anisotropy free ferromagnetic thin-layer material are respectively peeled from the two-dimensional layered source material block with the second-order nonlinear Hall effect and the perpendicular magnetic anisotropy free ferromagnetic source material block by a mechanical peeling method, the two-dimensional layered thin-layer material with the second-order nonlinear Hall effect is transferred to a first transition insulating layer on a first transition substrate to form a two-dimensional layered second-order nonlinear Hall effect layer, and the perpendicular magnetic anisotropy free ferromagnetic thin-layer material is transferred to a second transition insulating layer on a second transition substrate to form a perpendicular magnetic anisotropy free ferromagnetic layer; and obtaining a heterojunction formed by the two-dimensional layered second-order nonlinear Hall effect layer and the perpendicular magnetic anisotropy free ferromagnetic layer by using a dry transfer method.
9. The implementation method of claim 7, whichCharacterized in that in the step 2), the size of the Belgium curvature dipole moment is determined by measuring the second-order nonlinear Hall effect in the heterojunction, alternating current with the frequency of omega is introduced through the source-drain electrode, the second-order frequency Hall voltage with the frequency of 2 omega is measured through the measuring electrode, and the amplitude V of the second-order frequency Hall voltage is readacWhen adjusting the top gate voltage VTAnd back gate voltage VBSo that the amplitude V of the second order frequency Hall voltageacAt maximum, the dipole moment corresponding to the Belleville curvature is largest.
10. The method of claim 7, wherein in step 3), the write current IpGreater than critical current I capable of realizing magnetization reversal of perpendicular magnetic anisotropy in heterojunctionc。
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111345093.8A CN113782668B (en) | 2021-11-15 | 2021-11-15 | Magnetization turning device based on track transfer torque and implementation method thereof |
| PCT/CN2022/070023 WO2023082456A1 (en) | 2021-11-15 | 2022-01-04 | Magnetization reversal device based on orbital transfer torque and implementation method therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111345093.8A CN113782668B (en) | 2021-11-15 | 2021-11-15 | Magnetization turning device based on track transfer torque and implementation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113782668A CN113782668A (en) | 2021-12-10 |
| CN113782668B true CN113782668B (en) | 2022-02-11 |
Family
ID=78873836
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111345093.8A Active CN113782668B (en) | 2021-11-15 | 2021-11-15 | Magnetization turning device based on track transfer torque and implementation method thereof |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN113782668B (en) |
| WO (1) | WO2023082456A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113782668B (en) * | 2021-11-15 | 2022-02-11 | 北京大学 | Magnetization turning device based on track transfer torque and implementation method thereof |
| CN116403624B (en) * | 2023-06-08 | 2023-08-04 | 北京大学 | Track transfer torque magnetic random storage device and implementation method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6753562B1 (en) * | 2003-03-27 | 2004-06-22 | Sharp Laboratories Of America, Inc. | Spin transistor magnetic random access memory device |
| CN104393169A (en) * | 2014-10-10 | 2015-03-04 | 北京航空航天大学 | Spin-orbit torque magnetic random access memory (SOT-MRAM) without external magnetic field |
| CN112701214A (en) * | 2020-12-28 | 2021-04-23 | 西安交通大学 | Spin orbit torque magnetic random access memory with artificial anti-ferromagnetic free layer regulated by ferroelectrics |
| CN112701216A (en) * | 2020-12-28 | 2021-04-23 | 西安交通大学 | Magnetic multilayer structure and SOT-MRAM |
| CN113782668A (en) * | 2021-11-15 | 2021-12-10 | 北京大学 | Magnetization turning device based on track transfer torque and implementation method thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015102739A2 (en) * | 2013-10-18 | 2015-07-09 | Cornell University | Circuits and devices based on spin hall effect to apply a spin transfer torque with a component perpendicular to the plane of magnetic layers |
| CN110165045B (en) * | 2019-04-08 | 2021-05-25 | 中国科学院物理研究所 | W-B alloy material and spin-orbit torque-based spin electronic device |
| CN112968125B (en) * | 2021-02-26 | 2022-06-07 | 中国科学院微电子研究所 | Device for driving magnetic flip magnetic moment by spin orbit torque without external field and preparation method |
| CN113488584B (en) * | 2021-06-23 | 2023-04-07 | 华中科技大学 | FePt material-based magnetization switching device, external magnetic field-free switching method and application |
-
2021
- 2021-11-15 CN CN202111345093.8A patent/CN113782668B/en active Active
-
2022
- 2022-01-04 WO PCT/CN2022/070023 patent/WO2023082456A1/en unknown
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6753562B1 (en) * | 2003-03-27 | 2004-06-22 | Sharp Laboratories Of America, Inc. | Spin transistor magnetic random access memory device |
| CN104393169A (en) * | 2014-10-10 | 2015-03-04 | 北京航空航天大学 | Spin-orbit torque magnetic random access memory (SOT-MRAM) without external magnetic field |
| CN112701214A (en) * | 2020-12-28 | 2021-04-23 | 西安交通大学 | Spin orbit torque magnetic random access memory with artificial anti-ferromagnetic free layer regulated by ferroelectrics |
| CN112701216A (en) * | 2020-12-28 | 2021-04-23 | 西安交通大学 | Magnetic multilayer structure and SOT-MRAM |
| CN113782668A (en) * | 2021-11-15 | 2021-12-10 | 北京大学 | Magnetization turning device based on track transfer torque and implementation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2023082456A1 (en) | 2023-05-19 |
| CN113782668A (en) | 2021-12-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Yang et al. | Two-dimensional materials prospects for non-volatile spintronic memories | |
| Hirohata et al. | Review on spintronics: Principles and device applications | |
| Zhang et al. | Recent progress and challenges in magnetic tunnel junctions with 2D materials for spintronic applications | |
| Shao et al. | Roadmap of spin–orbit torques | |
| Ahn | 2D materials for spintronic devices | |
| Tsai et al. | Electrical manipulation of a topological antiferromagnetic state | |
| US8378329B2 (en) | Nanodevices for spintronics and methods of using same | |
| Liu et al. | Two-dimensional materials for energy-efficient spin–orbit torque devices | |
| Hirohata et al. | Future perspectives for spintronic devices | |
| Butler | Tunneling magnetoresistance from a symmetry filtering effect | |
| Ikeda et al. | Magnetic tunnel junctions for spintronic memories and beyond | |
| Dieny et al. | Spin-transfer effect and its use in spintronic components | |
| Cobas et al. | Room-temperature spin filtering in metallic ferromagnet–multilayer graphene–ferromagnet junctions | |
| Ohno et al. | Spintronics | |
| CN113782668B (en) | Magnetization turning device based on track transfer torque and implementation method thereof | |
| WO2019054484A1 (en) | METHOD FOR MANUFACTURING LAYERED STRUCTURE OF MAGNETIC BODY AND BiSb, MAGNETORESISTIVE MEMORY, AND PURE SPIN INJECTION SOURCE | |
| Wang et al. | Nonvolatile spintronics: perspectives on instant-on nonvolatile nanoelectronic systems | |
| Wu et al. | Field-free approaches for deterministic spin–orbit torque switching of the perpendicular magnet | |
| US10601371B2 (en) | Phase-locked spin torque oscillator array | |
| Hong et al. | 3D multilevel spin transfer torque devices | |
| Rybkina et al. | Advanced graphene recording device for spin–orbit torque magnetoresistive random access memory | |
| Titus et al. | Carbon nanotube based magnetic tunnel junctions (MTJs) for spintronics application | |
| Kumar et al. | Ultralow energy domain wall device for spin-based neuromorphic computing | |
| Shi et al. | Recent progress in strong spin-orbit coupling van der Waals materials and their heterostructures for spintronic applications | |
| CN116403624B (en) | Track transfer torque magnetic random storage device and implementation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |