Topological magnetic structure, magnetic skyrmion writing method and memory

Abstract

The present invention relates to a topological magnetic structure, a writing method of magnetic skyrmions, a memory, a read-write system and a racetrack memory. A topological magnetic structure includes: a substrate layer; a buffer layer, which is arranged on the substrate layer, and the surface roughness of the buffer layer is less than the surface roughness of the substrate layer; a magnetic layer, which is arranged on the buffer layer, and includes at least one ferrimagnetic layer, and the magnetic layer is used to generate magnetic skyrmions under preset conditions; a protective layer, which is arranged on the magnetic layer and is used to protect the magnetic layer. Devices based on ferrimagnetic materials have many advantages such as insensitivity to magnetic field disturbances and high intrinsic frequency, so they have broad application prospects in the fields of ultra-high density information storage and terahertz (THz).

Description

Technical Field

[0001] The present invention relates to a magnetic skyrmion information storage device, and in particular to a topological magnetic structure, a magnetic skyrmion writing method and a storage device. Background Art

[0002] With the rapid development of the information age, the explosive growth of data has also put forward higher requirements for information storage media. At present, as the size of traditional magnetic storage media decreases, the size limit caused by quantum effects and the resulting thermal effects have caused the development of traditional information storage materials to encounter bottlenecks. Spintronics technology introduces a new degree of freedom, electron spin. Spintronic devices have the advantages of low static power consumption, unlimited high-speed reading and writing, and non-volatile storage. They are considered to be the key technology to break through the current bottleneck and are expected to significantly reduce device power consumption and break through the shackles of thermal effects. Topological magnetic structures (magnetic skyrmions, vortex domains, etc.) are a type of particle-like spin structure with topological protection. Its related spin electronics applications have broad development prospects and are expected to become the next generation of new information storage carriers. Compared with traditional information storage carriers, it has obvious advantages: compared with traditional magnetic domains, the size of topological magnetic structures can be very small. Currently, the size of a single magnetic skyrmion can be as small as 5nm. The topological magnetic structure has the characteristics of topological protection. Compared with traditional magnetic domains, it is more stable and less susceptible to external conditions (magnetic field, temperature, etc.), which improves the stability of the device. The driving current of the topological magnetic structure is much smaller than the driving current of the domain wall, which fully reflects the low power consumption characteristics of information storage devices based on topological magnetic structures.

[0003] In traditional technology, using periodic spin-polarized pulse current to generate magnetic skyrmions in topological magnetic structures usually requires higher current density and longer writing time, which means higher energy consumption and slower data writing speed. Summary of the invention

[0004] Based on this, it is necessary to provide a topological magnetic structure, a magnetic skyrmion writing method and a memory, a read-write system and a racetrack memory to address the problems of high energy consumption and low efficiency in writing and storing data in the prior art.

[0005] A topological magnetic structure, comprising:

[0006] substrate layer;

[0007] A buffer layer is disposed on the substrate layer, and the surface roughness of the buffer layer is smaller than the surface roughness of the substrate layer;

[0008] A magnetic layer, disposed on the buffer layer, comprising at least one ferrimagnetic layer, the magnetic layer being used to generate magnetic skyrmions under preset conditions;

[0009] The protective layer is disposed on the magnetic layer and is used to protect the magnetic layer.

[0010] In one embodiment, the ferrimagnetic layer includes platinum, cobalt, and gadolinium arranged in a stack.

[0011] A method for writing magnetic skyrmions is applied to the topological magnetic structure as described above, and the writing method comprises:

[0012] The surface of the protective layer is irradiated with laser for a preset time so that the magnetic layer generates magnetic skyrmions.

[0013] In one embodiment, the preset time length is 100 femtoseconds.

[0014] In one embodiment, the laser wavelength is in the range of 700-800 nm.

[0015] In one embodiment, the frequency of the laser is 1 kHz.

[0016] A memory, comprising:

[0017] A plurality of topological magnetic structures as described above, wherein the substrate layer is a ferroelectric substrate;

[0018] A laser emitting unit, used for irradiating the surface of the protective layer with laser for a preset time, so as to generate magnetic skyrmions in the magnetic layer;

[0019] The driving unit is connected to the substrate layer and is used to drive the magnetic skyrmions to move in the topological magnetic structure to achieve information storage.

[0020] A reading and writing system, comprising:

[0021] A memory as above; and

[0022] The reading device is used to read the information stored in the memory.

[0023] A racetrack memory, comprising:

[0024] A nanobelt, comprising a topological magnetic structure as described above with a preset length, wherein the substrate layer material is silicon, and the nanobelt is divided into an information writing area, an information storage area and an information reading area in sequence along the length direction;

[0025] A laser emitting unit, located in the information writing area, is used to irradiate the surface of the protective layer with laser for a preset time so as to generate magnetic skyrmions in the magnetic layer;

[0026] The current driving unit has a positive pole located in the information reading area and a negative pole located in the information writing area, and is used to drive the magnetic skyrmions to move in the topological magnetic structure to achieve information storage.

[0027] In one embodiment, the information reading region is provided with a magnetic tunnel junction for reading magnetic skyrmions.

[0028] The above-mentioned topological magnetic structure includes: a substrate layer; a buffer layer, which is arranged on the substrate layer, and the surface roughness of the buffer layer is less than the surface roughness of the substrate layer; a magnetic layer, which is arranged on the buffer layer, including at least one ferrimagnetic layer, and the magnetic layer is used to generate magnetic skyrmions under preset conditions; a protective layer, which is arranged on the magnetic layer, is used to protect the magnetic layer. In the conventional technology, the magnetic layer is set as an ordinary ferromagnetic material, and the essential difference between ferrimagnetism and ferromagnetism is that the basic structure of the ferrimagnetic magnetic moment is composed of two parts, and there will be a part of the cancellation when the two magnetic moments are arranged in opposite directions. For example, the Co layer and the Gd layer are ferromagnetic layers, but the magnetic moments between the two layers are arranged in opposite directions, and the overall magnetization intensity is less than any single ferromagnetic layer. Therefore, compared with ferromagnetism, ferrimagnetic materials have a smaller ferromagnetic residual field. In terms of dynamics, devices based on ferrimagnetic materials have many advantages such as insensitivity to magnetic field disturbances and high intrinsic frequency. Therefore, they have broad application prospects in the fields of ultra-high density information storage and terahertz (THz). BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 This is one of the schematic diagrams of the topological magnetic structure in one embodiment;

[0031] Figure 2 This is a second schematic diagram of a topological magnetic structure in an embodiment;

[0032] Figure 3 This is a third schematic diagram of a topological magnetic structure in an embodiment;

[0033] Figure 4 This is a fourth schematic diagram of a topological magnetic structure in an embodiment;

[0034] Figure 5 A schematic diagram of a memory in an embodiment;

[0035] Figure 6 Schematic diagram of a track memory in one embodiment. DETAILED DESCRIPTION

[0036] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0038] It should be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it can be directly on, adjacent to, connected to, or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers.

[0039] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientations shown in the figures, spatially relative terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0040] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, in this specification, the term "and / or" includes any and all combinations of the relevant listed items.

[0041] Embodiments of the invention are described herein with reference to cross-sectional views which are schematic representations of idealized embodiments (and intermediate structures) of the invention, such that variations in the shapes shown due to, for example, manufacturing techniques and / or tolerances are anticipated. Thus, embodiments of the invention should not be limited to the particular shapes of the regions shown herein, but rather include deviations in shapes due to, for example, manufacturing techniques. Thus, the regions shown in the figures are schematic in nature, their shapes do not represent the actual shapes of the regions of the device, and do not limit the scope of the invention.

[0042] In one embodiment, if Figure 1 As shown, a topological magnetic structure 100 includes: a substrate layer 110, a buffer layer 120, a magnetic layer 130 and a protective layer 140. The buffer layer 120 is disposed on the substrate layer 110. The surface roughness of the buffer layer 120 is less than that of the substrate layer 110, and is used to provide a smooth surface, which is conducive to the deposition and adhesion of other layers to achieve a uniform structure. The magnetic layer 130 is disposed on the buffer layer 120, and includes at least one ferrimagnetic layer 131, such as Figure 2 and 3 As shown, it is used to generate magnetic skyrmions under preset conditions. The protective layer 140 is arranged on the magnetic layer 130. The protective layer material has high stability, inactivity and strong oxidation resistance, which can protect the magnetic layer from oxidation and extend the service life. Ferromagnetism refers to the phenomenon that the magnetic moments of adjacent atoms or ions in a substance are arranged in roughly the same direction in certain regions due to their interaction. When the applied magnetic field strength increases, the degree of directional arrangement of the combined magnetic moments in these regions will increase to a certain limit value. Ferrimagnetism is the phenomenon that in the absence of an external magnetic field, due to the exchange of electrons or other interactions between adjacent atoms in the magnetic domain. After overcoming the influence of thermal motion, their magnetic moments are in an orderly arrangement state of partial cancellation, so that there is also a phenomenon of a combined magnetic moment. Therefore, compared with ferromagnetic materials, ferrimagnetic materials have a smaller ferromagnetic residual field. In terms of dynamics, devices based on ferrimagnetic materials have many advantages such as insensitivity to magnetic field disturbances and high intrinsic frequency. Therefore, they have broad application prospects in fields such as ultra-high density information storage and terahertz (Tera Hertz, THz).

[0043] In one embodiment, the material of the buffer layer 120 is tantalum. Tantalum is a metal element with the element symbol Ta. Its corresponding single substance is a steel-gray metal with extremely high corrosion resistance. It does not react to hydrochloric acid, concentrated nitric acid and "aqua regia" under both cold and hot conditions. It is also ductile and can be drawn into thin foils in the form of filaments, and has a very small thermal expansion coefficient. Tantalum has very good chemical properties and has extremely high corrosion resistance. It is understandable that the buffer layer material is not limited to the above-mentioned tantalum single substance, but can be any other material as long as it can provide a smooth buffer surface, has high chemical stability, and does not react with the materials in contact with its upper and lower interfaces.

[0044] In one embodiment, the material of the magnetic layer 130 is at least one layer having a ferrimagnetic layer 131, wherein the material of the ferrimagnetic layer 131 is, for example, Figure 4 As shown, from the bottom to the top, they are arranged in order: platinum, cobalt, and gadolinium. Platinum is a chemical element with the chemical symbol Pt. It is one of the precious metals. Its single substance is commonly known as platinum. It belongs to the platinum series and has paramagnetism. It has good ductility, thermal conductivity and electrical conductivity. Its chemical properties are inactive and stable in air and humid environments. It is insoluble in hydrochloric acid, sulfuric acid, nitric acid and alkaline solutions, but soluble in aqua regia and molten alkali. Cobalt, element symbol Co, is a silvery-white ferromagnetic metal with a silvery-white surface with a slight pink color. It is a shiny steel-gray metal that is relatively hard and brittle. It has ferromagnetism and its magnetism disappears when heated to 1150°C. It does not react with water at room temperature and is also stable in humid air. Cobalt is an important raw material for the production of heat-resistant alloys, hard alloys, corrosion-resistant alloys, magnetic alloys and various cobalt salts. Gadolinium is a metal element with the element symbol Gd. It is silvery-white and ductile. Gadolinium is magnetic at room temperature. Gadolinium is relatively stable in dry air and loses its luster in wet air. It will play an important role in modern technological innovation. In this system, the Pt / Co interface produces perpendicular anisotropy, and the Co / Gd interface produces collinear antiferromagnetic coupling, which makes the overall ferrimagnetism appear.

[0045] In one embodiment, the material of the protective layer 140 is ruthenium. Ruthenium is a hard, brittle, light gray, multivalent rare metal element with the element symbol Ru. It is a member of the platinum group metals and has a content of only one billionth in the earth's crust. It is one of the rarest metals with very stable properties and strong corrosion resistance. It can withstand corrosion from hydrochloric acid, sulfuric acid, nitric acid and aqua regia at room temperature. Ruthenium is the cheapest metal in the platinum group metals, although other metals such as platinum and palladium are more abundant than ruthenium. It is understandable that the protective layer material is not limited to the above-mentioned ruthenium element, but can be any other material as long as it can ensure that the magnetic layer is not oxidized, has high chemical stability, and does not react with the magnetic layer material.

[0046] In one of the embodiments, a method for preparing a topological magnetic structure is provided. In this embodiment, the aforementioned topological magnetic structure is obtained by growing the magnetron sputtering technology. Magnetron sputtering is a "high-speed low-temperature sputtering technology" that has developed rapidly in the 1970s. Magnetron sputtering technology is to form an orthogonal electromagnetic field above the surface of the cathode target. When the secondary electrons generated by sputtering are accelerated into high-energy electrons in the cathode drop zone, they do not fly directly to the anode, but oscillate back and forth in a cycloidal motion under the action of the orthogonal electromagnetic field. High-energy electrons constantly collide with gas molecules and transfer energy to the latter, ionizing them and turning themselves into low-energy electrons. These low-energy electrons eventually drift along the magnetic lines to the auxiliary anode near the cathode and are absorbed, avoiding the strong bombardment of the high-energy electrons on the plate, eliminating the damage caused by the bombardment heating and electron irradiation of the plate in the dipole sputtering, and reflecting the "low temperature" characteristics of the plate in magnetron sputtering. Due to the presence of the external magnetic field, the complex movement of the electrons increases the ionization rate and realizes high-speed sputtering. The technical feature of magnetron sputtering is to generate a magnetic field perpendicular to the direction of the electric field near the cathode target surface, which is generally achieved using a permanent magnet.

[0047] Specifically, the power and pressure used on the magnetron sputtering instrument are first set, and during operation, the sputtering time is controlled to control the thickness of each layer produced on the substrate layer of the topological magnetic structure.

[0048] In one embodiment, a 5 nm buffer layer is deposited on the substrate layer using a magnetron sputtering device, a 5.8 nm magnetic layer is deposited on the buffer layer, and finally a 3 nm protective layer is deposited on the magnetic layer.

[0049] In one embodiment, the magnetic layer deposited on the buffer layer is composed of 2.5 nm of platinum material, 2.5 nm of cobalt material deposited on the platinum material, and 1 nm of ruthenium material deposited on the cobalt material.

[0050] In one of the embodiments, a method for writing magnetic skyrmions is provided. In this embodiment, the surface of the protective layer is irradiated with a laser for a preset time to make the magnetic layer produce magnetic skyrmions. The specific implementation method is to determine the wavelength, spot size and pulse time of the laser, and then irradiate it on the prepared topological magnetic structure. Among them, the writing principle that is currently recognized in the field has two mechanisms that work together to produce magnetic skyrmions. The first mechanism is that the temperature of the magnetic film at the laser irradiation spot increases, and the ferrimagnetic has a temperature compensation point. After the temperature rises above the compensation point, the magnetization direction will change, and the magnetization state at the spot will change to a non-equilibrium state. The second mechanism is that laser irradiation on the film will generate an equivalent magnetic field. The two mechanisms work together to achieve the writing of magnetic skyrmions on the ferrimagnetic film. Compared with the traditional writing of magnetic skyrmions, the present invention writes magnetic skyrmions into ferrimagnetic materials, writes magnetic skyrmions into magnetic films by irradiating ferrimagnetic films with laser, reduces the nucleation energy threshold of magnetic skyrmions in magnetic films, combines the magnetic temperature compensation point and dynamics of ferrimagnetic materials, and realizes ultrafast writing of skyrmions on magnetic films. Compared with traditional ferromagnetic materials, it has better application prospects in the field of information storage.

[0051] In one embodiment, the preset duration of laser irradiation is 100 femtoseconds.

[0052] In one embodiment, the wavelength of the laser is set within the range of 700-800 nm.

[0053] In one embodiment, the frequency of the laser is 1 kHz.

[0054] In one embodiment, the energy density of the laser at the irradiation spot is 3 mJ per square centimeter.

[0055] In one embodiment, a memory is provided, which includes: a plurality of the above-mentioned topological magnetic structures 100, a laser emitting unit 200 and a driving unit 300. Among them, the substrate layer 110 of the topological magnetic structure is a substrate made of ferroelectric material. Ferroelectric material refers to a type of material with ferroelectric effect. All ferroelectric materials have both ferroelectricity and piezoelectricity. Its most basic characteristic is that it has spontaneous polarization in certain temperature ranges, and the polarization intensity can be reversed with the reversal of the external electric field, thereby forming a hysteresis loop. The polarization state caused by the internal structure of the crystal, which is not caused by the external electric field, is called spontaneous polarization. Ferroelectricity refers to the spontaneous polarization of a material within a certain temperature range. Since the centers of positive and negative charges in the ferroelectric lattice do not coincide, an electric dipole moment can be generated even without an external electric field, and its spontaneous polarization can change direction under the action of an external electric field. When the temperature is higher than a certain critical value, its lattice structure changes, the centers of positive and negative charges coincide, and the spontaneous polarization disappears. This temperature critical value is called the Curie temperature (Tc). Piezoelectricity is a property that realizes the mutual conversion between mechanical energy and electrical energy. If an external force is applied to a material in a certain direction to cause the material to deform, polarization will occur inside it and charge will be generated on the surface. This is the piezoelectric effect. On the contrary, if an electric field is applied to the material, the material will deform and generate mechanical force. This is the inverse piezoelectric effect. All ferroelectric materials have the above two characteristics, which is one of the material foundations for building electromechanical systems.

[0056] The laser emitting unit 200 is used to irradiate the surface of the protective layer with laser for a preset time so as to generate magnetic skyrmions in the magnetic layer.

[0057] The driving unit 300 is connected to the substrate layer and is used to drive the magnetic skyrmions to move in the topological magnetic structure to achieve information storage.

[0058] In one embodiment, a read-write system is provided, comprising: the above-mentioned memory and a reading device for reading the storage information in the memory.

[0059] The traditional method of using spin-polarized current to write magnetic skyrmions on a racetrack memory usually requires a higher current density and a longer writing time. Compared with traditional technologies, the memory provided by the present invention can achieve lower energy consumption and faster data writing speed.

[0060] In one embodiment, if Figure 6As shown, a racetrack memory is provided, including: a nanobelt 400, a laser emitting unit 200 and a current driving unit 310, wherein the nanobelt 400 is made of the above-mentioned topological magnetic structure with a size of 200nm*1800nm*1nm. The substrate layer 110 in the topological magnetic structure is made of silicon. Because of the atomic structure of silicon, it has some special properties: the four valence electrons in the outermost layer make the silicon atoms in a metastable structure, and these valence electrons make the silicon atoms bond to each other by covalent bonds. Since the covalent bonds are relatively strong, silicon has a higher melting point and density; the chemical properties are relatively stable, and it is difficult to react with other substances (except hydrogen fluoride and alkali solution) at room temperature; there are no obvious free electrons in the silicon crystal, which can conduct electricity, but the conductivity is not as good as that of metals, and increases with the increase of temperature, and has semiconductor properties. The nanobelt is divided into an information writing area, an information storage area and an information reading area along the length direction.

[0061] The laser emitting unit 200 is located in the information writing area and is used to irradiate the surface of the protective layer with laser for a preset time so as to generate magnetic skyrmions in the magnetic layer.

[0062] The current driving unit 310 has a positive pole located in the information reading area and a negative pole located in the information writing area, and is used to drive the magnetic skyrmions to move in the topological magnetic structure to achieve information storage.

[0063] Among them, the racetrack memory uses the latest "racetrack" technology, which is a memory that uses the movement of magnetic skyrmions to store data. Magnetic skyrmions are thin film structures composed of atoms whose magnetic field directions change regularly. In the racetrack memory, nanoscale magnetic material wires are fixed at one end, and the direction of the current determines whether it is "1" or "0". In addition, the two ends of the memory are subjected to continuous pulse currents, which causes the movement of magnetic skyrmions. Therefore, the racetrack memory can achieve all-solid-state, high speed, extremely low power consumption, and data can be saved even when the power is off. The storage capacity reaches the level of hard disks.

[0064] In one embodiment, the information reading area of ​​the racetrack memory is provided with a magnetic tunnel junction (MTJs) for reading magnetic skyrmions. Magnetic tunnel junctions (MTJs) are a sandwich structure inhomogeneous magnetic system of ferromagnetic metal / insulator / ferromagnetic metal. The spin polarized tunneling process of the metal oxide (usually aluminum oxide) barrier between two ferromagnetic metal films (such as chromium, cobalt, nickel or iron nickel) can also produce a giant magnetoresistance effect. Under the action of a voltage across the insulating layer, the tunnel current and tunnel resistance of this magnetic tunnel junction depend on the relative orientation of the magnetization strength of the two ferromagnetic layers. When this relative orientation changes under the action of an external magnetic field, a large tunneling magnetoresistance (TMR) can be observed. (Magnetic tunnel junctions (MTJs) have much higher magnetic field sensitivity than metal multilayer films. At the same time, the structure of magnetic tunnel junctions (MTJs) itself has high resistivity, low energy consumption and stable performance. Therefore, magnetic tunnel junctions (MTJs) have unparalleled advantages whether used as read heads, various sensors, or magnetic random access memory (MRAM).

[0065] In one embodiment, the information storage area of ​​the racetrack memory can be divided into a number of storage units along the track direction of the magnetic nanobelt, and each storage unit can store the state of a magnetic skyrmion. The magnetic skyrmions in the information storage part enter the information reading part, and the information reading part reads the polarity of the magnetic skyrmions passing therethrough, thereby reading the binary number "0" or "1", thereby realizing information storage and information reading.

[0066] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0067] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features of the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A topological magnetic structure, characterized in that: include: substrate layer; A buffer layer is disposed on the substrate layer, and the surface roughness of the buffer layer is smaller than the surface roughness of the substrate layer; A magnetic layer, disposed on the buffer layer, comprising at least one ferrimagnetic layer, wherein the magnetic layer is used to generate magnetic skyrmions under preset conditions; the ferrimagnetic layer comprises platinum, cobalt and gadolinium arranged in a stacked manner; the magnetic moment of the interface between the platinum and the cobalt is opposite to the direction of the interface magnetic moment between the cobalt and the gadolinium; The protective layer is disposed on the magnetic layer and is used to protect the magnetic layer.

2. A method for writing magnetic skyrmions, characterized in that: Applied to the topological magnetic structure as claimed in claim 1, the writing method comprises: The surface of the protective layer is irradiated with laser light for a preset time so that the magnetic layer generates the magnetic skyrmions.

3. The method according to claim 2, characterized in that The preset time length is 100 femtoseconds.

4. The method according to claim 2, characterized in that: The laser wavelength is in the range of 700-800 nm.

5. The method according to claim 2, characterized in that: The frequency of the laser is 1 kHz.

6. A memory, characterized in that: include: A plurality of topological magnetic structures as claimed in claim 1, wherein the substrate layer is a ferroelectric substrate; A laser emitting unit, used for irradiating the surface of the protective layer with laser for a preset time, so that the magnetic layer generates the magnetic skyrmions; A driving unit is connected to the substrate layer and is used to drive the magnetic skyrmions to move in the topological magnetic structure to achieve information storage.

7. A reading and writing system, characterized in that: include: The memory as claimed in claim 6; and The reading device is used to read the information stored in the memory.

8. A racetrack memory, characterized in that: include: A nanobelt, comprising a topological magnetic structure according to claim 1 of a preset length, wherein the substrate layer material is silicon, and the nanobelt is divided into an information writing area, an information storage area and an information reading area in sequence along the length direction; A laser emitting unit, located in the information writing area, is used to irradiate the surface of the protective layer with laser for a preset time so that the magnetic layer generates the magnetic skyrmions; A current driving unit, with a positive pole located in the information reading area and a negative pole located in the information writing area, is used to drive the magnetic skyrmions to move in the topological magnetic structure to achieve information storage.

9. The racetrack memory according to claim 8, characterized in that: The information reading area is provided with a magnetic tunnel junction for reading the magnetic skyrmions.

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