Method for inducing magnetic skyrmion based on geometric structure design

Abstract

The invention discloses a method for inducing magnetic skyrmion based on geometric structure design, and the method specifically comprises the steps: constructing geometric structures such as corrugations, folds, recesses and the like in a two-dimensional magnetic material, breaking the center inversion symmetry to induce the interaction of Dzyaloshiski-Moriya (DM), and providing conditions for designing topological magnetic structures such as magnetic skyrmion and the like; through calculation of a first principle, magnetic parameters of a researched system are presented in detail, including Heisenberg exchange coupling, DM interaction, magnetic anisotropy and the like; on the basis of micro-magnetic simulation, magnetic ground states, including topological magnetic structures such as magnetic skyrmion and the like, under various magnetic interaction competition are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of spin electronics devices, and in particular relates to a method for inducing magnetic skyrmions based on geometric structure design. Background Art

[0002] Currently, information storage and logic operation architectures in spintronic devices rely on low-dimensional systems with well-defined symmetries. Research has mainly focused on single crystals, epitaxial thin films, and multilayer stacked structures, which have almost perfect long-range order and symmetry. However, even in ideal materials and interfaces, there are still structural and chemical composition inhomogeneities and disorder.

[0003] A new approach to describing these defects is to define them as functions of curvature in real space, reciprocal space, or spin space. Since the microscopic features of entangled and topological states are largely influenced by local atomic and nanoscale features, local curvature can be used to design systems with spontaneous or inhomogeneous inversion symmetry breaking, thereby stabilizing the three-dimensional magnetization vector field or regulating topological and magnetotransport properties in electronic systems. In addition, experimentally synthesized two-dimensional materials, whether freely suspended or grown on a substrate, will inevitably produce curvature, which has been reported in materials such as graphene and MoS2. In real space, the effects of local curvature changes are mainly manifested as structural, chemical, electronic and magnetic inhomogeneities and disorders, whose amplitudes are proportional to the ratio of the spatial changes. Sufficiently large ratios can affect magnetic properties, such as stabilizing topological magnetic structures on the corresponding length scale.

[0004] In addition, it is necessary to design an artificially designed curved nanostructure that can adjust the magnetic exchange interaction without damaging the inherent properties; and it can be different from the traditional voltage, stress or strain control methods, and can control the magnetic exchange interaction of two-dimensional magnetic materials and new technical methods of topological magnetic structure through curvature. Today, there is an urgent need to use convenient means to distort, deform or even change the required three-dimensional curved surface magnetization vector field to achieve magnetic chirality effects and design more complex magnetic configuration technologies. Summary of the invention

[0005] The purpose of the present invention is to address the problem that existing magnetic skyrmions are difficult to generate and regulate in two-dimensional magnetic materials, and to provide a method for inducing magnetic skyrmions based on geometric structure design; periodic corrugated structures, folded structures and concave structures are designed in a single-layer two-dimensional magnetic material to break its inversion symmetry and induce DM interaction. At the same time, based on theoretical calculations, it is found that the dependence of DM interaction on curvature can be well explained by the three-point Fert-Lévy model. By using curvature to regulate the size of magnetic parameters such as Heisenberg exchange coupling, DM interaction and magnetic anisotropy, magnetic skyrmions can be stabilized in a single-layer two-dimensional magnetic material.

[0006] The present invention is realized by the following technical scheme: a method for inducing magnetic skyrmions based on geometric structure design, comprising the following steps:

[0007] (1) Based on the planar structure of two-dimensional magnetic materials, the surface geometric configuration is modeled at the atomic scale according to the mathematical forms of different geometric configurations; and for each surface geometric configuration, a magnetic surface geometric system with different curvatures is obtained by adjusting the size of the curvature;

[0008] (2) Extracting magnetic parameters in magnetic surface geometric systems with different curvatures through first-principles calculations, including Heisenberg exchange coupling, DM interaction, and magnetic anisotropy;

[0009] (3) Analyze the variation of magnetic parameters under different curvatures and obtain the regulation mode of curvature on magnetic parameters of magnetic surface geometric system;

[0010] (4) With reference to the calculated magnetic parameters and surface geometry, the positions of magnetic atoms and their neighbor interactions are modeled, and the ground state of the magnetic skyrmion is solved based on micromagnetic simulations.

[0011] Furthermore, the two-dimensional magnetic material in step (1) may be selected from Fe3GaTe2, Fe3GeTe2, Fe5GeTe2, Cr2Te3, Cr3Te4, but is not limited to any one or more combinations thereof.

[0012] Furthermore, the curved surface geometric configuration in step (1) includes a periodic corrugated structure, a folded structure and a concave structure.

[0013] Furthermore, the curvature of the curved surface geometric configuration in step (1) is

[0014] Furthermore, the ratio of the DM interaction and the Heisenberg exchange coupling calculated by the magnetic surface geometric system with different curvatures in step (2) is 0.05 to 0.25, preferably 0.1 to 0.2.

[0015] Furthermore, the magnetic anisotropy calculated by the magnetic surface geometric system with different curvatures in step (2) is along the normal direction of the magnetic material surface.

[0016] Furthermore, the ratio of the DM interaction and the Heisenberg exchange coupling in the magnetic curved surface geometry system in (3) increases with the increase of curvature.

[0017] Furthermore, the magnetic skyrmion ground state solved in (4) includes any one or more combinations of Néel-type magnetic skyrmions, Bloch-type magnetic skyrmions and antimagnetic skyrmions.

[0018] An electronic device, comprising:

[0019] one or more processors;

[0020] A memory for storing one or more programs;

[0021] When the one or more programs are executed by the one or more processors, the one or more processors implement the method of inducing magnetic skyrmions based on geometric structure design.

[0022] A computer-readable storage medium stores computer instructions, which, when executed by a processor, implement the method steps for designing induced magnetic skyrmions based on geometric structures.

[0023] The beneficial effects of the present invention are as follows:

[0024] The present invention discloses designing periodic corrugated structures, folded structures and concave structures in a single-layer two-dimensional magnetic material, breaking its inversion symmetry and inducing DM interaction. At the same time, based on theoretical calculations, it is found that the dependence of DM interaction on curvature can be well explained by the three-point Fert-Lévy model, and the curvature is used to regulate the magnitude of magnetic parameters such as Heisenberg exchange coupling, DM interaction and magnetic anisotropy, thus achieving technical innovation in stabilizing magnetic skyrmions in a single-layer two-dimensional magnetic material. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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.

[0026] Figure 1 It is a diagram of the curved surface geometric model of the present invention; wherein (a) is a diagram of the periodic corrugation of the curved surface, (b) is a diagram of the folding of the curved surface, and (c) is a diagram of the geometric configuration of the concave structure of the curved surface.

[0027] Figure 2 The magnetic parameter diagram extracted by the calculation of the curved surface geometry model of the present invention; wherein (a) is a diagram showing the variation of the DM interaction energy EDM(q) in a single-layer Fe3GeTe2 with a curved surface geometry with the spin helical wave vector q, and (b) is a diagram showing the variation of the DM interaction parameter d in a single-layer Fe3GeTe2 with a curved surface geometry with the curvature κ.

[0028] Figure 3 This is the ground state diagram of the magnetic skyrmion obtained by the present invention based on micromagnetic simulation; wherein (a) is a diagram of the magnetic structure in a single-layer Fe3GeTe2 with a curved geometric structure, and (b) is an enlarged diagram of the magnetic configuration of an isolated Néel-type magnetic skyrmion. DETAILED DESCRIPTION

[0029] Here, exemplary embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

[0030] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0031] In order to more clearly explain the technical solutions and advantages of the present invention, the present invention is further described in detail with reference to embodiments and accompanying drawings. Note that the specific embodiments described herein are only used to explain the present invention, not to limit the present invention.

[0032] The present invention provides a method for inducing magnetic skyrmions in a two-dimensional magnetic material based on geometric structure design, the method comprising the following steps:

[0033] (1) Taking a single layer of two-dimensional magnetic material Fe3GaTe2 as an example, based on the planar structure, atomic-scale modeling was performed according to the mathematical form of the curved surface geometric configuration. For each geometric configuration, material models with different degrees of curvature were obtained by adjusting the size of the curvature. Figure 1 It is a geometric configuration diagram of surface periodic corrugation, surface folding and surface concave structure; (a) is a surface periodic corrugation diagram, (b) is a surface folding diagram, and (c) is a surface concave structure geometric configuration diagram. Figure 1 It can be seen that each curved surface geometric configuration includes a rigid area and a curved surface geometric area. The rigid area is configured as a planar structure of Fe3GaTe2, and the curved surface geometric area satisfies the mathematical form distribution of the curved surface geometric configuration, and the different degrees of bending are characterized by the size of the curvature.

[0034] (2) Through first-principles calculations, the magnetic parameters such as Heisenberg exchange coupling, DM interaction and magnetic anisotropy of Fe3GeTe2 with magnetic surface geometric configurations of different curvatures are extracted. Figure 2 The magnetic parameter diagrams extracted from the calculation of curved Fe3GeTe2 with different curvatures, where (a) is the variation of the DM interaction energy EDM(q) in a single-layer Fe3GeTe2 with a curved surface geometry with the spin helical wave vector q, and (b) is the variation of the DM interaction parameter d in a single-layer Fe3GeTe2 with a curved surface geometry with the curvature κ. Figure 2It can be seen that the DM interaction parameter of curved Fe3GeTe2 increases with the increase of curvature. The ratio of DM interaction and Heisenberg exchange coupling of bent Fe3GeTe2 is 0.12.

[0035] (3) According to the curvature The magnetic atomic positions of the bent Fe3GeTe2 and the calculated extracted neighbor magnetic interaction parameters are modeled, and the magnetic skyrmion ground state is solved based on micromagnetic simulations. Figure 3 The simulated curvature is The magnetic structure of the bent Fe3GeTe2 under zero field. Figure 3 It can be seen that, among them, (a) is a magnetic structure diagram in a single-layer Fe3GeTe2 with a curved geometric structure, and (b) is an enlarged diagram of the magnetic configuration of an isolated Néel-type magnetic skyrmion; the magnetic ground state of the curved Fe3GeTe2 is a magnetic skyrmion lattice state, and according to the enlarged diagram of the arrangement of the magnetic moment direction, it can be seen that the magnetic skyrmions formed in the curved Fe3GeTe2 by the method of the present invention are Néel-type magnetic skyrmions, which have room temperature non-volatility and zero-field stability.

[0036] In some embodiments of the present invention, the two-dimensional magnetic material may be selected from Fe3GaTe2, Fe3GeTe2, Fe5GeTe2, Cr2Te3, Cr3Te4, but is not limited to one or more thereof.

[0037] An electronic device, comprising:

[0038] one or more processors;

[0039] A memory for storing one or more programs;

[0040] When the one or more programs are executed by the one or more processors, the one or more processors implement the method of inducing magnetic skyrmions based on geometric structure design.

[0041] A computer-readable storage medium stores computer instructions, which, when executed by a processor, implement the method steps for designing induced magnetic skyrmions based on geometric structures.

[0042] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the contents disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art that are not disclosed in the present application.

[0043] It should be understood that the present application is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof.

Claims

1. A method for inducing magnetic skyrmions based on geometric structure design, characterized in that: The following steps are involved: (1) Based on the planar structure of two-dimensional magnetic materials, the surface geometric configuration is modeled at the atomic scale according to the mathematical forms of different geometric configurations; and for each surface geometric configuration, a magnetic surface geometric system with different curvatures is obtained by adjusting the size of the curvature; (2) Extracting magnetic parameters in magnetic surface geometric systems with different curvatures through first-principles calculations, including Heisenberg exchange coupling, DM interaction, and magnetic anisotropy; (3) Analyze the variation of magnetic parameters under different curvatures and obtain the regulation mode of curvature on magnetic parameters of magnetic surface geometric system; (4) With reference to the calculated magnetic parameters and surface geometry, the positions of magnetic atoms and their neighbor interactions are modeled, and the ground state of the magnetic skyrmion is solved based on micromagnetic simulations.

2. The method for inducing magnetic skyrmions based on geometric structure design according to claim 1, characterized in that: The two-dimensional magnetic material in step (1) is selected from Fe3GaTe2, Fe3GeTe2, Fe5GeTe2, Cr2Te3, Cr3Te4, but is not limited to any one or more combinations thereof.

3. The method for inducing magnetic skyrmions based on geometric structure design according to claim 1, characterized in that: The curved surface geometric configuration in step (1) includes a periodic corrugated structure, a folded structure and a concave structure.

4. The method for inducing magnetic skyrmions based on geometric structure design according to claim 1, characterized in that: The curvature of the curved surface geometric configuration in step (1) is 5. The method for inducing magnetic skyrmions based on geometric structure design according to claim 1, characterized in that: In the step (2), the ratio of the DM interaction to the Heisenberg exchange coupling calculated by the magnetic surface geometric system with different curvatures is 0.05 to 0.25, preferably 0.1 to 0.

2.

6. The method according to any one of claims 1 to 5, a method for inducing magnetic skyrmions based on geometric structure design, characterized in that: The magnetic anisotropy calculated by the magnetic surface geometric system with different curvatures in step (2) is along the normal direction of the magnetic material surface.

7. A method for inducing magnetic skyrmions based on geometric structure design according to claim 1, characterized in that: In the step (3), the ratio of the DM interaction and the Heisenberg exchange coupling of the magnetic curved surface geometric system increases as the curvature increases.

8. A method for inducing magnetic skyrmions based on geometric structure design according to claim 1, characterized in that: The magnetic skyrmion ground state solved in step (4) includes any one or more combinations of Néel-type magnetic skyrmions, Bloch-type magnetic skyrmions and diamagnetic skyrmions.

9. An electronic device, characterized in that: include: one or more processors; A memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method for inducing magnetic skyrmions based on geometric structure design as described in any one of claims 1 to 7.

10. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the instruction is executed by the processor, the method steps of inducing magnetic skyrmions based on geometric structure design as described in any one of claims 1 to 7 are implemented.

Images