Magnetic anisotropy energy research method, device, equipment, medium and program product

Abstract

The present application discloses a magnetic anisotropy energy research method, device, equipment, medium and program product, which relates to the field of magnetic material technology, including: obtaining the target magnetic material to be studied and configuring the initial magnetic state of the target magnetic material; performing a density functional theory calculation with spin-orbit coupling on the target magnetic material under the initial magnetic state to obtain the electronic structure physical quantity of the target magnetic material; according to the electronic structure physical quantity combined with the Green's function method, the magnetic anisotropy energy result of each magnetic moment of the target magnetic material is calculated once, and based on the magnetic anisotropy energy result of each magnetic moment of the target magnetic material, the magnetic anisotropy energy analysis is performed. The present application can avoid the complex calculation process of density functional theory with multiple spin-orbit coupling, circumvent the problem of difficult convergence of the calculation process, and improve the efficiency of calculating and analyzing magnetic anisotropy energy.

Description

Technical Field

[0001] The present application relates to the technical field of magnetic materials, and in particular to a magnetic anisotropy energy research method, a magnetic anisotropy energy research device, a magnetic anisotropy energy research equipment, a storage medium and a computer program product. Background Art

[0002] The calculation of magnetic anisotropy energy (MAE) is crucial in the study of magnetic materials. It describes the energy difference of a material in different magnetic moment directions. The magnetic anisotropy energy of a magnetic material is mainly caused by the spin-orbit coupling (SOC) effect.

[0003] Currently, when calculating the MAE of multiple magnetic moment directions, it is necessary to perform multiple density functional theory (DFT) calculations on the magnetic material with spin-orbit coupling, and then calculate the MAE based on the energy differences of the magnetic material in multiple magnetic moment directions. This method of calculating multiple magnetic moment directions has a complex process and difficult calculation convergence, which leads to low MAE calculation efficiency and is not friendly to high-throughput MAE calculations. Summary of the invention

[0004] The main purpose of this application is to provide a magnetic anisotropy energy research method, a magnetic anisotropy energy research device, a magnetic anisotropy energy research equipment, a storage medium and a computer program product, aiming to solve the technical problem that the calculation process of MAE is complicated and inefficient.

[0005] To achieve the above objectives, the present application proposes a method for studying magnetic anisotropy energy, the method comprising:

[0006] Acquire a target magnetic material to be studied and configure an initial magnetic state of the target magnetic material;

[0007] Performing a density functional theory calculation with spin-orbit coupling on the target magnetic material in the initial magnetic state to obtain electronic structure physical quantities of the target magnetic material;

[0008] According to the electronic structure physical quantity combined with the Green's function method, the magnetic anisotropy energy results of each magnetic moment of the target magnetic material are calculated at one time, and based on the magnetic anisotropy energy results of each magnetic moment of the target magnetic material, magnetic anisotropy energy analysis is performed.

[0009] In one embodiment, the step of calculating the magnetic anisotropy energy result of each magnetic moment of the target magnetic material at one time according to the electronic structure physical quantity combined with the Green's function method comprises:

[0010] In the configured spin space of the target magnetic material, solving a first total energy with the first spin pointing downward and a second total energy with the second spin pointing downward by using the electronic structure physical quantity;

[0011] The difference between the first total energy and the second total energy is taken as the magnetic anisotropy energy result.

[0012] In one embodiment, the magnetic anisotropy energy result includes a difference between a first total energy of the target magnetic material under a first spin orientation and a second total energy under a second spin orientation; the step of performing magnetic anisotropy energy analysis based on the magnetic anisotropy energy results of each magnetic moment orientation of the target magnetic material includes:

[0013] Determining a hard magnetization axis and an easy magnetization axis of the target magnetic material by a difference between the first total energy and the second total energy;

[0014] The magnetic anisotropy energy orientation of the target magnetic material is determined according to the hard magnetization axis and the easy magnetization axis.

[0015] In one embodiment, the step of performing magnetic anisotropy energy analysis based on the magnetic anisotropy energy results of the magnetic moments of the target magnetic material further includes:

[0016] Project the magnetic anisotropy energy results onto atoms and atomic orbitals to obtain atomic projection energy and atomic orbital projection energy;

[0017] According to the atomic projection energy and the atomic orbital projection energy, the atomic components contributing to the magnetic anisotropy energy and the atomic orbitals contributing to the magnetic anisotropy energy are analyzed and obtained.

[0018] In one embodiment, the step of analyzing and obtaining the atomic components contributing to the magnetic anisotropy energy and the atomic orbitals contributing to the magnetic anisotropy energy according to the atomic projection energy and the atomic orbital projection energy comprises:

[0019] Determining target atoms among atoms constituting a target magnetic material according to the atomic projection energy, wherein the target atoms are atomic components that contribute to a magnetic anisotropy energy result;

[0020] According to the atomic orbital projection energy, the atomic orbital in the target atom that contributes to the magnetic anisotropy energy result is obtained.

[0021] In one embodiment, the method comprises:

[0022] According to the magnetic anisotropy energy analysis result, the magnetic anisotropy energy change of the target magnetic material is obtained;

[0023] According to the change in magnetic anisotropy energy, the magnetic anisotropy energy result of the target magnetic material is regulated to optimize the target magnetic material.

[0024] In addition, to achieve the above-mentioned purpose, the present application also proposes a magnetic anisotropy energy research device, which includes: an acquisition module, used to acquire a target magnetic material to be studied and configure an initial magnetic state of the target magnetic material;

[0025] A calculation module, used for performing a density functional theory calculation with spin-orbit coupling on the target magnetic material in the initial magnetic state to obtain electronic structure physical quantities of the target magnetic material;

[0026] The analysis module is used to calculate the magnetic anisotropy energy results of each magnetic moment of the target magnetic material at one time according to the electronic structure physical quantity combined with the Green's function method, and perform magnetic anisotropy energy analysis based on the magnetic anisotropy energy results of each magnetic moment of the target magnetic material.

[0027] In addition, to achieve the above-mentioned purpose, the present application also proposes a magnetic anisotropy energy research device, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the magnetic anisotropy energy research method as described above.

[0028] In addition, to achieve the above-mentioned purpose, the present application also proposes a storage medium, which is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the magnetic anisotropy energy research method as described above are implemented.

[0029] In addition, to achieve the above-mentioned purpose, the present application also provides a computer program product, which includes a computer program, and when the computer program is executed by a processor, the steps of the magnetic anisotropy energy research method as described above are implemented.

[0030] One or more technical solutions proposed in this application have at least the following technical effects:

[0031] Compared with the existing calculation of the magnetic anisotropy energy of magnetic materials, multiple DFT calculations with spin-orbit coupling need to be performed to obtain energy differences in multiple magnetic moment directions and the magnetic anisotropy energy of the magnetic material, which has complex processes and difficult calculation convergence, resulting in low MAE calculation efficiency, which is not conducive to high-throughput MAE calculation; the present application obtains electronic structure physical quantities through a density functional theory calculation with spin-orbit coupling once, and then calculates the magnetic anisotropy energy results of each magnetic moment direction based on the electronic structure physical quantities combined with the Green's function method, and after obtaining the magnetic anisotropy energy results, magnetic anisotropy energy analysis can be performed; only one DFT calculation with SOC needs to be performed, and the MAE results of multiple different magnetic moment directions can be directly obtained by combining the Green's function method, avoiding the complex calculation process of the density functional theory with spin-orbit coupling multiple times, avoiding the problem of difficult convergence of the calculation process, and improving the efficiency of calculating and analyzing the magnetic anisotropy energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 A schematic diagram of a flow chart provided for the first embodiment of the magnetic anisotropy energy research method of the present application;

[0035] Figure 2 A schematic diagram of a flow chart provided for the second embodiment of the magnetic anisotropy energy research method of the present application;

[0036] Figure 3 A schematic diagram showing the variation of magnetic anisotropy energy with angle in the magnetic anisotropy energy research method of the present application;

[0037] Figure 4 A schematic diagram of the change of magnetic anisotropy energy at different layer thicknesses in the magnetic anisotropy energy research method of this application;

[0038] Figure 5 A schematic diagram of the contribution of different atomic orbits in the magnetic anisotropy energy research method of this application;

[0039] Figure 6 A brief flow chart of the magnetic anisotropy energy research method provided for this application;

[0040] Figure 7This is a schematic diagram of the module structure of the magnetic anisotropy energy research device of this application;

[0041] Figure 8 This is a schematic diagram of the device structure of the hardware operating environment involved in the magnetic anisotropy energy research method of this application.

[0042] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0043] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0044] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0045] The existing methods for calculating MAE are mainly: 1. Total energy difference method: calculate the total energy of different magnetic moment directions through density functional theory (DFT), and then calculate the total energy difference between each two magnetic moment directions to obtain MAE. 2. Perturbation theory method: first calculate the electronic structure without spin-orbit coupling (SOC), and then estimate the SOC contribution through perturbation theory to obtain MAE. 3. Anisotropy constant method: calculate MAE by measuring the value of the material in different magnetic moment directions, and then combining it with a specific theoretical model or calculation formula.

[0046] In the total energy difference method, at least two different direction energies, such as E(001) and E(100), must be estimated to obtain MAE. The perturbation theory method must first calculate the energy of the system with and without SOC and then combine some perturbations to calculate MAE. The anisotropy constant method usually measures the anisotropy constant K of multiple magnetic moment directions to calculate MAE.

[0047] In order to obtain the MAE of multiple magnetic moment orientations, these methods need to calculate the energies of multiple different spin orientations. High-throughput MAE calculations require a lot of computing resources for large-scale data processing and analysis. When multiple DFT calculations with spin-orbit coupling are performed, a large amount of computation will be generated. Not only is the calculation process complicated, but the energy calculations of different magnetic moment orientations are difficult to converge, and the convergence state estimation is inaccurate, which limits the high-throughput MAE calculations.

[0048] It should be noted that the execution subject of this embodiment can be a magnetic anisotropy energy research device, or a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device, a processor, etc. that can realize the above functions. The following takes the magnetic anisotropy energy research device as an example to illustrate this embodiment and the following embodiments.

[0049] Based on this, the present application embodiment provides a method for studying magnetic anisotropy energy, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the magnetic anisotropy energy research method of the present application.

[0050] In this embodiment, the magnetic anisotropy energy research method includes steps S10 to S30:

[0051] Step S10, obtaining a target magnetic material to be studied and configuring an initial magnetic state of the target magnetic material;

[0052] It should be noted that the target magnetic material may be a ferromagnetic material, a ferrimagnetic material, etc. When calculating the magnetic anisotropy energy of the magnetic material, a density functional theory calculation is performed according to the characteristics of the material.

[0053] The initial magnetic state of the target magnetic material is an initial spin state specified for the spin atoms of the magnetic material, which is usually set to the magnetic order of the ground state, such as the ferromagnetic ground state, and illustratively, is set to the 001 direction.

[0054] Step S20, performing a density functional theory calculation with spin-orbit coupling on the target magnetic material in the initial magnetic state to obtain electronic structure physical quantities of the target magnetic material;

[0055] It should be noted that spin-orbit coupling (SOC) is a relativistic effect. In magnetic materials, it has an important influence on the electronic structure. Adding spin-orbit coupling to density functional theory calculations can more accurately describe the electronic behavior in magnetic materials.

[0056] The electronic structure physics includes many quantities that describe the electronic properties of magnetic materials, for example, the real-space Hamiltonian matrix containing SOC , overlap matrix S(R), real space Hamiltonian matrix independent of SOC effect , Fermi level , structure files, atomic orbital information, etc. These physical quantities can reflect important information such as the distribution and energy state of electrons in magnetic materials.

[0057] In a feasible implementation manner, the magnetic anisotropy energy research method includes:

[0058] The target magnetic material is subjected to spin-orbit coupling once when density functional theory calculation converges, or the target magnetic material is subjected to spin-orbit coupling once after density functional theory calculation converges.

[0059] It should be noted that the convergence process of density functional theory calculations is a self-consistent process. In density functional theory calculations, the self-consistent process is to adjust the electron wave function and charge density through continuous iteration until a stable state is reached, that is, convergence is achieved.

[0060] When the calculation converges, the SOC effect is used as a perturbation correction to affect the evolution of the electronic state in real time, so that the calculation results converge towards a stable state that includes the SOC effect. After the density functional theory calculation has reached convergence, spin-orbit coupling is added, and SOC is added as a perturbation correction, which is equivalent to making small adjustments based on the already converged electronic structure.

[0061] Step S30, according to the electronic structure physical quantity combined with the Green's function method, the magnetic anisotropy energy results of each magnetic moment of the target magnetic material are calculated at one time, and the magnetic anisotropy energy analysis is performed based on the magnetic anisotropy energy results of each magnetic moment of the target magnetic material.

[0062] It should be noted that magnetic anisotropy refers to the phenomenon that magnetic materials exhibit different magnetic properties in different magnetic moment directions, and the magnetic anisotropy energy describes the energy difference of materials in different magnetic moment directions. The electronic structure physical quantities calculated by density functional theory with spin-orbit coupling reflect the distribution and energy state of electrons in the material, and the state of electrons directly affects the magnetic anisotropy.

[0063] In one embodiment, the magnetic anisotropy energy result may be solved by a Green's function method.

[0064] In this embodiment, the electronic structure physical quantities of the target magnetic material are obtained by a density functional theory calculation with spin-orbit coupling added once, wherein the spin-orbit coupling is equivalent to the perturbation effect, and then based on the calculated electronic structure physical quantities combined with the Green's function method, the energies in multiple magnetic moment directions are calculated at one time, thereby obtaining the MAE in each magnetic moment direction; through the above steps, there is no need to perform DFT calculations with SOC added in multiple magnetic moment directions, which can greatly reduce the amount of calculation and avoid the complex density functional theory calculation process with multiple spin-orbit coupling added. At the same time, it can also circumvent the problem of difficult convergence of the magnetic moment direction system, thereby improving the efficiency of calculating and analyzing magnetic anisotropy energy.

[0065] In a feasible implementation manner, the magnetic anisotropy energy result includes the difference between a first total energy of the target magnetic material under a first spin orientation and a second total energy under a second spin orientation; step S30, the magnetic anisotropy energy analysis based on the magnetic anisotropy energy result of each magnetic moment orientation of the target magnetic material includes steps A10 to A20:

[0066] Step A10, determining the hard magnetization axis and the easy magnetization axis of the target magnetic material by the difference between the first total energy and the second total energy;

[0067] It should be noted that in magnetic materials, materials have different total energies under different spin directions, and the total energy reflects the overall energy state of the magnetic material under a specific spin state. For the target magnetic material, there will be a difference between the total energy under the first spin direction and the total energy under the second spin direction. The difference between the first total energy and the second total energy is the MAE result. To determine the hard magnetization axis and the easy magnetization axis of the target magnetic material, it is necessary to solve the maximum absolute value of the difference between the first total energy under the first spin direction and the second total energy under the second spin direction; the maximum absolute value of the difference is related to the magnetization axis properties of the material.

[0068] The hard magnetization axis refers to the axis in the magnetic material that is difficult to magnetize along this direction. When the absolute value of the difference between the first total energy with the first spin pointing downward and the second total energy with the second spin pointing downward is the largest, it corresponds to the direction with the largest energy change. In this direction, the magnetization process needs to overcome a large energy barrier, so this direction is the hard magnetization axis. Because in order to magnetize the material in this direction, the energy state of the material needs to be changed, and this energy change is the largest relative to other directions.

[0069] The easy magnetization axis is the opposite of the hard magnetization axis, and is the axis that is relatively easy to magnetize along this direction in magnetic materials. Since the direction with the largest energy change (most difficult to magnetize) has been determined when the absolute value of the difference between the first total energy with the first spin pointing downward and the second total energy with the second spin pointing downward is the largest, the direction perpendicular to it or the direction that is most conducive to magnetization in terms of energy is the easy magnetization axis. In this direction, the energy change when the material is magnetized is relatively small, and it is easier to magnetize.

[0070] Step A20, determining the magnetic anisotropy energy orientation of the target magnetic material according to the hard magnetization axis and the easy magnetization axis.

[0071] It should be noted that in magnetic materials, the distribution of energy is related to the difficulty of magnetization. After the hard magnetization axis and the easy magnetization axis are determined, the energy in the direction of the easy magnetization axis is lower, while the energy in the direction of the hard magnetization axis is higher. Therefore, the magnetic anisotropy energy, as a physical quantity that describes the energy difference in different magnetization directions, points from the easy magnetization axis with low energy to the hard magnetization axis with high energy.

[0072] In this embodiment, the hard magnetization axis and the easy magnetization axis of the target magnetic material are determined by calculating the maximum absolute value of the total energy difference under different spin directions, and then the direction of the magnetic anisotropy energy result of the target magnetic material is determined based on the determined hard magnetization axis and the easy magnetization axis, which helps to optimize the use of magnetic materials.

[0073] In another feasible implementation, the magnetic anisotropy energy result includes the atomic projection energy and atomic orbital projection energy of the target magnetic material in the first spin direction and the second spin direction respectively; step S30, the magnetic anisotropy energy analysis based on the magnetic anisotropy energy result of each magnetic moment direction of the target magnetic material includes steps B10 to B20:

[0074] Step B10, projecting the magnetic anisotropy energy result onto atoms and atomic orbitals to obtain atomic projection energy and atomic orbital projection energy;

[0075] It should be noted that in order to perform MAE analysis, after obtaining the magnetic anisotropy energy results, the magnetic anisotropy energy results are projected onto atoms and atomic orbitals to obtain atomic projection energy and atomic orbital projection energy, so as to analyze which atoms contribute mainly to MAE. For atoms that contribute more to MAE, the projection of atomic orbitals can be used to determine which orbitals contribute to the main MAE of the system.

[0076] Step B20, analyzing and obtaining the atomic components contributing to the magnetic anisotropy energy and the atomic orbitals contributing to the magnetic anisotropy energy based on the atomic projection energy and the atomic orbital projection energy.

[0077] It should be noted that the atomic projection energy is the energy component related to each atom obtained by projecting the total energy of the system according to the atoms, reflecting the contribution of each atom to the energy of the entire system. The atomic orbital projection energy is an energy component obtained by further projecting the energy of the atom according to the atomic orbital on the basis of the atomic projection energy, which can reveal the contribution of different atomic orbitals to the atomic energy.

[0078] By analyzing the atomic projection energy, we can determine which atoms contribute to the magnetic anisotropy energy; for the atomic orbital projection energy, we can analyze the contribution of different atomic orbitals to the magnetic anisotropy energy.

[0079] In this embodiment, MAE analysis based on MAE results can accurately identify the atomic components and atomic orbitals that contribute to the magnetic anisotropy energy, and the magnetic anisotropy energy of the target magnetic material can be regulated by changing the target atoms or atomic orbitals, thereby improving the performance of the magnetic material.

[0080] In one embodiment, the origin of magnetic anisotropy energy is obtained based on atomic components, and the mechanism of magnetic anisotropy energy generation is obtained based on atomic orbital analysis.

[0081] It should be noted that atomic component refers to the contribution of each atom in the system to the overall properties. In a magnetic material system, different atoms have different electronic structures, atomic radii, chemical bonding with surrounding atoms and other characteristics. When considering atomic components, the existence and properties of specific atoms will affect the origin of magnetic anisotropy energy.

[0082] Atomic orbitals are regions in atoms where electrons exist. Different atomic orbitals have different shapes, energies, and spatial orientations. In magnetic materials, atomic orbitals overlap and interact with each other. The difference in the interaction between atomic orbitals in different directions causes the distribution of electron clouds to be asymmetric in different directions, making the energy required for magnetization in different directions different. The mechanism of magnetic anisotropy energy generation can be analyzed based on atomic orbitals.

[0083] In another embodiment, in step B20, the magnetic anisotropy energy research method comprises:

[0084] Determining target atoms among atoms constituting the target magnetic material according to the atomic projection energy, wherein the target atoms are atomic components that contribute to the magnetic anisotropy energy result;

[0085] According to the atomic orbital projection energy, the atomic orbitals in the target atom that contribute to the magnetic anisotropy energy result are obtained.

[0086] It should be noted that in the target magnetic material, each atom that constitutes the target magnetic material has different influences on the magnetic anisotropy energy result. Each atom has its own atomic projection energy, which reflects the contribution of the atom to the energy of the entire system. By analyzing the atomic projection energy, those atoms that contribute to the magnetic anisotropy energy result can be identified, and these atoms are the target atoms.

[0087] The atomic orbital projection energy is obtained by further subdividing the energy of the atom according to the atomic orbital on the basis of the atomic projection energy. Since different atomic orbitals have different electron cloud distributions, energy states and other characteristics, their contributions to the magnetic anisotropy energy results are also different. The atomic orbital projection energy of the target atom is analyzed to find out the atomic orbitals that contribute to the magnetic anisotropy energy results.

[0088] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the first embodiment can refer to the above introduction, and will not be repeated in the following. Figure 2 , step S20, the magnetic anisotropy energy research method further includes steps D10 to D20:

[0089] Step D10, in the configured spin space of the target magnetic material, solving the first total energy when the first spin points downward and the second total energy when the second spin points downward by using the electronic structure physical quantity;

[0090] It should be noted that when calculating MAE, it is necessary to consider the energy difference of the material in different magnetization directions. By configuring the target to solve the spin space, physical quantities such as total energy, atomic projection energy, and atomic orbital projection energy under different spin directions can be calculated in a targeted manner. Axis angle , the second spin points to Axis angle , the spin direction can be set by different and The value is controlled, usually and The value of can be configured between [0, 2π]. In the range [0, 2π], by selecting different and By combining these two methods, countless spin directions can be obtained, thereby solving the magnetic crystal anisotropy energy in multiple directions at once, thereby comprehensively studying the properties of magnetic materials in different magnetization directions.

[0091] The electronic structure physical quantity is obtained by performing a DFT calculation with SOC added in step S20.

[0092] Specifically, it can be solved by the Green function method:

[0093] ;

[0094] Among them, the formula Indicated in The real-space Hamiltonian matrix containing the SOC at the point, express Point and Green's function between points, represents the Fermi level, It means to find the imaginary part of the matrix. The magnetic quantum number is and the spin quantum number is Trace of the matrix.

[0095] Step D20, taking the difference between the first total energy and the second total energy as the magnetic anisotropy energy result.

[0096] It should be noted that the Green function method in step D20 is used to solve different and The total energy under different values, and then solve and The energy difference under the value is used to obtain MAE.

[0097] In this embodiment, since the spin space is configured, by selecting different and By combining the electronic structure physics and the Green's function method, countless spin directions can be obtained. Therefore, the magnetic anisotropy energy of the target magnetic material in multiple directions can be solved at once in the Green's function by the electronic structure physics. The magnetic anisotropy energy results of each magnetic moment direction of the target magnetic material to be studied are calculated. By using the electronic structure physics and the Green's function method to solve the total energy under different spin directions in a specific target magnetic material spin space and obtain the magnetic anisotropy energy results, the efficiency of MAE evaluation of the target magnetic material is improved.

[0098] Based on the first embodiment of the present application, in the third embodiment of the present application, the same or similar contents as those in the first embodiment can be referred to the above description and will not be described in detail later. After step S30, the magnetic anisotropy energy research method further includes steps T10 to T20:

[0099] Step T10, obtaining a change in magnetic anisotropy energy of a target magnetic material according to a result of magnetic anisotropy energy analysis;

[0100] It should be noted that the results of magnetic anisotropy energy analysis include the direction of magnetic anisotropy energy, the origin of magnetic anisotropy energy and the mechanism of magnetic anisotropy energy generation. By analyzing the direction of magnetic anisotropy energy of magnetic materials (determining the distribution of magnetic anisotropy energy in a specific direction in space), understanding the origin of magnetic anisotropy energy (crystal structure, spin-orbit coupling and other factors) and mastering the mechanism of magnetic anisotropy energy generation (spin-orbit coupling, exchange interaction, etc.), it is possible to determine how the magnetic anisotropy energy of the magnetic material changes under different conditions (such as temperature changes, changes in the direction and intensity of the external magnetic field, etc.).

[0101] Step T20, regulating the magnetic anisotropy energy result of the target magnetic material according to the change of the magnetic anisotropy energy, so as to optimize the target magnetic material.

[0102] It should be noted that by using the known law of change of magnetic anisotropy energy, corresponding measures can be taken to change the size or direction of the magnetic anisotropy energy. For example, if it is found that the magnetic anisotropy energy of a certain magnetic material drops sharply within a specific temperature range, the magnetic anisotropy energy can be adjusted by controlling the temperature; by precisely controlling the magnetic anisotropy energy results, the target magnetic material can be optimized.

[0103] In this embodiment, the change of magnetic anisotropy energy is obtained according to the direction, origin and generation mechanism of magnetic anisotropy energy, and the essence of magnetic anisotropy of target magnetic material is deeply analyzed, which helps to fully understand the performance of magnetic anisotropy of magnetic materials under different conditions; the magnetic anisotropy energy results are regulated according to the change of magnetic anisotropy energy, thereby improving the efficiency of analysis of target magnetic materials.

[0104] In one application scenario, the target magnetic material is a two-dimensional Structure, first of all, six layers from 1 to 6 The structure performs DFT calculations with SOC and outputs the Hamiltonian matrix , overlap matrix S(R), real space Hamiltonian matrix independent of SOC effect , Fermi level , structure files, atomic orbital information, etc.; then read the corresponding , The output orbital and other file information are combined with the Green's function method to calculate the total MAE of the magnetic material system, and project it to each atomic component and different atomic orbital components; then MAE analysis is performed based on the MAE results.

[0105] The specific MAE analysis is as follows: First, analyze the MAE direction and set the angle with the x-axis , control the different angles with the z-axis , Therefore, the larger the positive value, the greater the energy required for the spin to flip to that direction, and the less likely the spin is to point to that direction, which is the difficult magnetization axis. Figure 3 The MAE is given as shown ( ) with the change of the angle with the z-axis when the MAE (unit: meV), where the angle with the z-axis is zero, that is Figure 3 When α=0.00π, MAE( ) value is 0 Figure 3 When α=0.00π, the MAE of atom A, the MAE of atom B, and the total MAE are all 0, indicating that the energy is lowest when the spin is along the z-axis, and the angle with the z-axis is The value is the largest when it is perpendicular to the z-axis (i.e., the x-axis). The greater the energy required to flip the spin to the x-axis, the more difficult it is for the spin to point in that direction. The x-axis is the difficult magnetization axis; therefore, the z-axis is the easy magnetization axis, and the spin ground state of the system points in the z direction.

[0106] Then analyze the atomic contribution and the contribution of different orbitals of contributing atoms, from Figure 3It can be seen that when the blue line (MAE of atom B) fluctuates, the red line (total MAE of the system) fluctuates accordingly. When the green line (MAE of atom A) fluctuates, it has little effect on the red line (total MAE of the system). Therefore, it can be concluded that atom B contributes more to the total MAE of the system.

[0107] like Figure 4 The change of MAE under different layer thicknesses is shown in the figure. According to the above analysis, When the MAE value is the largest, the MAE is plotted ( ) With the change of thickness, such as Figure 4 It can be seen that the MAE (MAE of A atoms, MAE of B atoms, and total MAE of the system) decreases with increasing thickness, and the MAE contribution of A and B atoms also decreases with increasing thickness, and the main contribution comes from B atoms. Figure 4 It can also be seen that after the thickness reaches 5 layers, the MAE (MAE of atom A, MAE of atom B, and total MAE of the system) values ​​begin to become flat and the MAE values ​​decrease.

[0108] Further analysis of the contribution of different orbitals of the B atom, such as Figure 5 After the atomic orbital projection, it is concluded that the MAE of atom B comes from the p orbital, because the p orbital has an x-axis, a y-axis, and a z-axis, and nine groups are obtained by combining two by two, that is, , , ; , , ; , , .

[0109] in , , Contributes negative value (such as Figure 5 As shown, the three sets of plotted lines are all below 0.0. , These two sets of lines overlap, and the other set is , ), the other 6 groups contribute positive values; as the thickness increases, , , , The positive contribution of the orbit gradually decreases, , , The overall change is not significant, due to , The absolute value of the negative contribution tends to become larger, resulting in a smaller overall MAE value.

[0110] For example, in order to help understand the implementation process of the magnetic anisotropy energy research method obtained by combining this embodiment with the above-mentioned first embodiment, please refer to Figure 6 , Figure 6 A brief schematic diagram of the magnetic anisotropy energy research method is provided, specifically:

[0111] The first step is to perform DFT calculations, which specifically include: preparing the target magnetic material, initializing the spin atomic magnetization direction for the target magnetic material, that is, configuring the initial magnetic state, performing a DFT calculation with SOC under the initial magnetic state, and outputting the electronic structure physical quantities.

[0112] The second step is to perform MAE calculation, which specifically includes: configuring the spin space, reading the electronic structure physical quantities output by the first step DFT calculation, solving them in combination with the Green's function method, and calculating the difference in total energy to obtain the MAE result.

[0113] The third step is to perform MAE analysis. According to the MAE results, the absolute maximum value of the total energy difference is calculated to analyze the MAE direction. The total energy is projected onto atoms and atomic orbitals to obtain atomic projection energy and atomic orbital projection energy. The atomic components contributing to MAE and the atomic orbitals contributing to MAE are analyzed, and MAE is regulated based on the analysis results.

[0114] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the magnetic anisotropy energy research method of the present application. More forms of simple transformations based on this technical concept, such as the interaction and combination of various embodiments, are all within the scope of protection of the present application.

[0115] This application also provides a magnetic anisotropy energy research device, please refer to Figure 7 , the magnetic anisotropy energy research device comprises:

[0116] An acquisition module 10, used to acquire a target magnetic material to be studied and configure an initial magnetic state of the target magnetic material;

[0117] A calculation module 20 is used to perform a density functional theory calculation with spin-orbit coupling on the target magnetic material in the initial magnetic state to obtain electronic structure physical quantities of the target magnetic material;

[0118] The analysis module 30 is used to calculate the magnetic anisotropy energy results of each magnetic moment of the target magnetic material in one time according to the electronic structure physical quantity combined with the Green's function method, and perform magnetic anisotropy energy analysis based on the magnetic anisotropy energy results of each magnetic moment of the target magnetic material.

[0119] Optionally, the analysis module 30 is further used to solve the first total energy directed downward by the first spin and the second total energy directed downward by the second spin in the configured spin space of the target magnetic material by using the electronic structure physical quantity;

[0120] The difference between the first total energy and the second total energy is taken as the magnetic anisotropy energy result.

[0121] Optionally, the analysis module 30 is further configured to determine a hard magnetization axis and an easy magnetization axis of the target magnetic material according to a difference between the first total energy and the second total energy;

[0122] The magnetic anisotropy energy orientation of the target magnetic material is determined according to the hard magnetization axis and the easy magnetization axis.

[0123] Optionally, the analysis module 30 is further used to project the magnetic anisotropy energy result onto atoms and atomic orbitals to obtain atomic projection energy and atomic orbital projection energy;

[0124] According to the atomic projection energy and the atomic orbital projection energy, the atomic components contributing to the magnetic anisotropy energy and the atomic orbitals contributing to the magnetic anisotropy energy are analyzed and obtained.

[0125] Optionally, the analysis module 30 is further used to determine target atoms among atoms constituting the target magnetic material according to the atomic projection energy, wherein the target atoms are atomic components that contribute to the magnetic anisotropy energy result;

[0126] According to the atomic orbital projection energy, the atomic orbital in the target atom that contributes to the magnetic anisotropy energy result is obtained.

[0127] The magnetic anisotropy energy research device includes a control module for: obtaining a change in magnetic anisotropy energy of a target magnetic material according to a result of magnetic anisotropy energy analysis;

[0128] According to the change in magnetic anisotropy energy, the magnetic anisotropy energy result of the target magnetic material is regulated to optimize the target magnetic material.

[0129] The magnetic anisotropy energy research device provided by the present application adopts the magnetic anisotropy energy research method in the above embodiment, which can solve the technical problem that the calculation process of MAE is complicated and inefficient. Compared with the prior art, the beneficial effects of the magnetic anisotropy energy research device provided by the present application are the same as the beneficial effects of the magnetic anisotropy energy research method provided by the above embodiment, and the other technical features in the magnetic anisotropy energy research device are the same as the features disclosed in the above embodiment method, which will not be repeated here.

[0130] The present application provides a magnetic anisotropy energy research device, which includes: at least one processor; and a memory that is communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the magnetic anisotropy energy research method in the first embodiment described above.

[0131] Reference below Figure 8 , which shows a schematic diagram of the structure of a magnetic anisotropy energy research device suitable for implementing the embodiment of the present application. The magnetic anisotropy energy research device in the embodiment of the present application may include but is not limited to mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 8 The magnetic anisotropy energy research device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0132] like Figure 8As shown, the magnetic anisotropy energy research device may include a processing device 1001 (such as a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM: Read Only Memory) 1002 or a program loaded from a storage device 1003 to a random access memory (RAM: Random Access Memory) 1004. Various programs and data required for the operation of the magnetic anisotropy energy research device are also stored in the RAM 1004. The processing device 1001, the ROM 1002, and the RAM 1004 are connected to each other through a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to the I / O interface 1006: input devices 1007 including, for example, a touch screen, a touchpad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; output devices 1008 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; storage devices 1003 including, for example, a magnetic tape, a hard disk, etc.; and communication devices 1009. The communication device 1009 can allow the magnetic anisotropy energy research device to communicate with other devices wirelessly or wired to exchange data. Although the magnetic anisotropy energy research device with various systems is shown in the figure, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems may be implemented or have alternatively.

[0133] In particular, according to the embodiments disclosed in the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication device, or installed from a storage device 1003, or installed from a ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present application are executed.

[0134] The magnetic anisotropy energy research device provided by the present application adopts the magnetic anisotropy energy research method in the above embodiment, which can solve the technical problem that the calculation process of MAE is complicated and inefficient. Compared with the prior art, the beneficial effects of the magnetic anisotropy energy research device provided by the present application are the same as the beneficial effects of the magnetic anisotropy energy research method provided by the above embodiment, and the other technical features in the magnetic anisotropy energy research device are the same as the features disclosed in the method of the previous embodiment, which will not be repeated here.

[0135] It should be understood that the various parts disclosed in this application can be implemented by hardware, software, firmware or a combination thereof. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0136] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0137] The present application provides a computer-readable storage medium having computer-readable program instructions (ie, computer programs) stored thereon, and the computer-readable program instructions are used to execute the magnetic anisotropy energy research method in the above-mentioned embodiment.

[0138] The computer-readable storage medium provided in the present application may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems or devices, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM: Random Access Memory), a read-only memory (ROM: Read Only Memory), an erasable programmable read-only memory (EPROM: Erasable Programmable Read Only Memory or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM: CD-Read Only Memory), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system or device. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency: Radio Frequency), etc., or any suitable combination of the above.

[0139] The computer-readable storage medium may be included in the magnetic anisotropy energy research device; or may exist independently without being assembled into the magnetic anisotropy energy research device.

[0140] The computer-readable storage medium carries one or more programs. When the one or more programs are executed by the magnetic anisotropy energy research device, the magnetic anisotropy energy research device: obtains a target magnetic material to be studied and configures an initial magnetic state of the target magnetic material;

[0141] Performing a density functional theory calculation with spin-orbit coupling on the target magnetic material in the initial magnetic state to obtain electronic structure physical quantities of the target magnetic material;

[0142] According to the electronic structure physical quantity combined with the Green's function method, the magnetic anisotropy energy results of each magnetic moment of the target magnetic material are calculated at one time, and based on the magnetic anisotropy energy results of each magnetic moment of the target magnetic material, magnetic anisotropy energy analysis is performed.

[0143] Computer program code for performing the operations of the present application may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0144] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0145] The modules involved in the embodiments described in this application may be implemented by software or hardware, wherein the name of the module does not constitute a limitation on the unit itself in some cases.

[0146] The readable storage medium provided in the present application is a computer-readable storage medium, which stores computer-readable program instructions (i.e., computer programs) for executing the above-mentioned magnetic anisotropy energy research method, and can solve the technical problem that the calculation process of MAE is complicated and inefficient. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in the present application are the same as the beneficial effects of the magnetic anisotropy energy research method provided in the above-mentioned embodiment, and will not be repeated here.

[0147] The present application also provides a computer program product, including a computer program, which implements the steps of the magnetic anisotropy energy research method as described above when executed by a processor.

[0148] The computer program product provided by the present application can solve the technical problem that the calculation process of MAE is complicated and inefficient. Compared with the prior art, the beneficial effects of the computer program product provided by the present application are the same as the beneficial effects of the magnetic anisotropy energy research method provided by the above embodiment, which will not be repeated here.

[0149] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A method for studying magnetic anisotropy energy, characterized in that: The method comprises the following steps: Acquire a target magnetic material to be studied and configure an initial magnetic state of the target magnetic material; Performing a density functional theory calculation with spin-orbit coupling on the target magnetic material in the initial magnetic state to obtain electronic structure physical quantities of the target magnetic material; In the configured spin space of the target magnetic material, based on the first spin pointing to The angle between the axis and the direction of the second spin The angle between the axes is calculated based on the electronic structure physical quantity combined with the Green's function method to obtain the magnetic anisotropy energy results of each magnetic moment of the target magnetic material at one time, and the magnetic anisotropy energy analysis is performed based on the magnetic anisotropy energy results of each magnetic moment of the target magnetic material.

2. The magnetic anisotropy energy research method according to claim 1, characterized in that: The step of calculating the magnetic anisotropy energy result directed by each magnetic moment of the target magnetic material at one time according to the electronic structure physical quantity combined with the Green's function method comprises: In the configured spin space of the target magnetic material, solving a first total energy with the first spin pointing downward and a second total energy with the second spin pointing downward by using the electronic structure physical quantity; The difference between the first total energy and the second total energy is taken as the magnetic anisotropy energy result.

3. The magnetic anisotropy energy research method according to claim 1, characterized in that: The magnetic anisotropy energy result includes a difference between a first total energy of the target magnetic material in a first spin orientation and a second total energy in a second spin orientation; The step of performing magnetic anisotropy energy analysis based on the magnetic anisotropy energy results directed by each magnetic moment of the target magnetic material comprises: Determining a hard magnetization axis and an easy magnetization axis of the target magnetic material by a difference between the first total energy and the second total energy; The magnetic anisotropy energy orientation of the target magnetic material is determined according to the hard magnetization axis and the easy magnetization axis.

4. The magnetic anisotropy energy research method according to claim 1, characterized in that: The step of performing magnetic anisotropy energy analysis based on the magnetic anisotropy energy results of the magnetic moments of the target magnetic material further includes: Project the magnetic anisotropy energy results onto atoms and atomic orbitals to obtain atomic projection energy and atomic orbital projection energy; According to the atomic projection energy and the atomic orbital projection energy, the atomic components contributing to the magnetic anisotropy energy and the atomic orbitals contributing to the magnetic anisotropy energy are analyzed and obtained.

5. The magnetic anisotropy energy research method according to claim 4, characterized in that: The step of analyzing and obtaining the atomic components contributing to the magnetic anisotropy energy and the atomic orbitals contributing to the magnetic anisotropy energy according to the atomic projection energy and the atomic orbital projection energy comprises: Determining target atoms among atoms constituting a target magnetic material according to the atomic projection energy, wherein the target atoms are atomic components that contribute to a magnetic anisotropy energy result; According to the atomic orbital projection energy, the atomic orbital in the target atom that contributes to the magnetic anisotropy energy result is obtained.

6. The magnetic anisotropy energy research method according to claim 1, characterized in that: After the step of performing magnetic anisotropy energy analysis based on the magnetic anisotropy energy results of the magnetic moments of the target magnetic material, the method further comprises: According to the magnetic anisotropy energy analysis result, the magnetic anisotropy energy change of the target magnetic material is obtained; According to the change in magnetic anisotropy energy, the magnetic anisotropy energy result of the target magnetic material is regulated to optimize the target magnetic material.

7. A magnetic anisotropy energy research device, characterized in that: The magnetic anisotropy energy research device comprises: An acquisition module, used for acquiring a target magnetic material to be studied and configuring an initial magnetic state of the target magnetic material; A calculation module, used for performing a density functional theory calculation with spin-orbit coupling on the target magnetic material in the initial magnetic state to obtain electronic structure physical quantities of the target magnetic material; The analysis module is used to calculate the magnetic anisotropy energy results of each magnetic moment pointing of the target magnetic material at one time in the configured spin space of the target magnetic material based on the angle between the first spin direction and the axis and the angle between the second spin direction and the axis according to the electronic structure physical quantity combined with the Green's function method, and perform magnetic anisotropy energy analysis based on the magnetic anisotropy energy results of each magnetic moment pointing of the target magnetic material.

8. A magnetic anisotropy energy research device, characterized in that: The device comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the magnetic anisotropy energy research method according to any one of claims 1 to 6.

9. A storage medium, characterized in that: The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the magnetic anisotropy energy research method according to any one of claims 1 to 6 are implemented.

10. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the steps of the magnetic anisotropy energy research method according to any one of claims 1 to 6 are implemented.

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