Magnetic skyrmion forming method based on femtosecond laser pulse regulation and writing device

Abstract

The invention discloses a magnetic skyrmion forming method and writing device based on femtosecond laser pulse regulation and control. The method comprises the following steps: acquiring a CoFeB nano-disk and placing the CoFeB nano-disk in a sample placing area of a magneto-optical Kerr effect microscope; pulse excitation is carried out on the CoFeB nanodisk by adjusting femtosecond laser thermal pulses, generation and annihilation of the Skyrmion of the CoFeB nanodisk in a preset area are controlled, and the number and position of the Skyrmion are obtained; and writing and reading data according to the generation and annihilation of the Skyrmion and the number and position of the Skyrmion. The device comprises a femtosecond laser pulser, a CoFeB nanodisk and a temperature sensor. According to the embodiment of the invention, the energy consumption can be reduced, the interference of external noise is avoided, and the precise control capability of the number and position of the skyrmion is improved. The method can be widely applied to the technical field of spintronics.

Description

Technical Field

[0001] The present application relates to the technical field of spin electronics, and in particular to a method for forming magnetic skyrmions and a writing device based on femtosecond laser pulse regulation. Background Art

[0002] Skyrmions are spin structures with topological protection properties that exhibit unique quasi-particle properties in magnetic materials. Skyrmions have broad application potential in high-density data storage, logic operations, and brain-like computing devices due to their high stability, small size, and insensitivity to external interference. Skyrmions-based spin electronics devices have significant advantages over traditional storage and computing devices in terms of power consumption, speed, and density, and have therefore become a research hotspot in the fields of spin electronics and nanotechnology. CoFeB (cobalt iron boron) is a magnetic material that is widely used to study the properties of skyrmions. Its excellent perpendicular magnetic anisotropy and stability make the generation and control of skyrmions in it more efficient. However, the generation and stability of skyrmions are highly dependent on the thickness of the material layer, interface effects (such as the Dzyal osh insk ii-Mor iya interaction, DM I effect), and other external excitations. However, there are currently two main methods for controlling skyrmions, namely current injection and external magnetic field. However, these methods have the problem of high power consumption of electric current or magnetic field, and the movement or annihilation process of skyrmions is easily disturbed by external noise, making it difficult to achieve ideal control accuracy.

[0003] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the invention

[0004] The main purpose of the embodiments of the present application is to propose a method for forming magnetic skyrmions and a writing device based on femtosecond laser pulse regulation, which can reduce energy consumption, avoid interference from external noise, and thereby improve the ability to accurately control the number and position of skyrmions.

[0005] To achieve the above-mentioned purpose, one aspect of the embodiments of the present application proposes a method for forming magnetic skyrmions based on femtosecond laser pulse regulation, the method comprising the following steps:

[0006] Obtain the CoFeB nanodisk and place it in the sample placement area of ​​the magneto-optical Kerr effect microscope;

[0007] By adjusting a femtosecond laser thermal pulse to pulse excite the CoFeB nanodisk, the generation and annihilation of skyrmions in a preset area of ​​the CoFeB nanodisk are controlled, and the number and position of skyrmions are obtained;

[0008] Data is written and read according to the generation and annihilation of the skyrmions and the number and position of the skyrmions.

[0009] In some embodiments, the step of pulse-exciting the CoFeB nanodisk by adjusting a femtosecond laser thermal pulse, controlling the generation and annihilation of skyrmions in a preset area of ​​the CoFeB nanodisk, and obtaining the number and position of skyrmions includes:

[0010] According to the preset thermal excitation conditions, adjusting the femtosecond laser thermal pulse;

[0011] Performing pulse excitation on a preset area of ​​the CoFeB nanodisk according to the adjusted femtosecond laser thermal pulse to control the generation and annihilation of skyrmions in the preset area of ​​the CoFeB nanodisk;

[0012] According to the generation and annihilation of skyrmions, the number and position of skyrmions are determined.

[0013] In some embodiments, the preset thermal excitation conditions include a pulse temperature range, a pulse duration, and a pulse number, wherein:

[0014] The pulse temperature range is used to control the generation and annihilation of skyrmions in the CoFeB nanodisk in a preset area;

[0015] The pulse duration and the pulse number are used to achieve the response and control of the skyrmions in the CoFeB nanodisk in a preset area.

[0016] In some embodiments, the pulse temperature range includes a first preset pulse temperature range and a second preset pulse temperature range, the first preset pulse temperature range is greater than the second preset pulse temperature range, wherein:

[0017] The first preset pulse temperature range is used to control the generation of skyrmions of the CoFeB nanodisk in a preset area;

[0018] The second preset pulse temperature range is used to control the annihilation of skyrmions of the CoFeB nanodisk in a preset area.

[0019] In some embodiments, the femtosecond laser thermal pulse transmits heat to a preset region of the CoFeB nanodisk by an optical method, and a spatial range of the femtosecond laser thermal pulse is equal to a spatial range of the preset region of the CoFeB nanodisk.

[0020] In some embodiments, the writing and reading of data according to the generation and annihilation of the skyrmions and the number and position of the skyrmions includes:

[0021] Writing data through the generation and annihilation of the skyrmions;

[0022] The data is read out based on the number and position of the skyrmions.

[0023] To achieve the above-mentioned purpose, another aspect of the embodiment of the present application proposes a magnetic skyrmion writing device based on femtosecond laser pulse regulation, the device comprising a femtosecond laser pulser, a CoFeB nanodisk and a temperature sensor, the central axis of the femtosecond laser pulser and the center of the CoFeB nanodisk are on the same straight line, the temperature sensor and the CoFeB nanodisk are connected in a non-contact manner, wherein:

[0024] The femtosecond laser pulser is used to emit femtosecond laser thermal pulses;

[0025] The CoFeB nanodisk is used to control the generation and annihilation of skyrmions according to the femtosecond laser thermal pulse;

[0026] The temperature sensor is used to detect the temperature of the femtosecond laser thermal pulse.

[0027] In some embodiments, the femtosecond laser pulser comprises a femtosecond laser, a first lens, an aperture, a second lens, a polarizer, a third lens and an objective lens, wherein the first lens, the aperture, the second lens, the polarizer, the third lens and the objective lens are sequentially placed along the direction of the femtosecond laser thermal pulse emitted by the femtosecond laser, wherein:

[0028] The femtosecond laser is used to generate the femtosecond laser thermal pulse;

[0029] The first lens is used to collimate and focus the femtosecond laser thermal pulse to obtain a focused femtosecond laser thermal pulse;

[0030] The aperture is used to adjust the cross-sectional diameter and shape of the focused femtosecond laser thermal pulse to obtain an adjusted femtosecond laser thermal pulse;

[0031] The second lens is used to perform beam energy density distribution optimization processing on the adjusted femtosecond laser thermal pulse to obtain an optimized femtosecond laser thermal pulse;

[0032] The polarizer is used to filter the optimized femtosecond laser thermal pulse to obtain a filtered femtosecond laser thermal pulse;

[0033] The third lens is used to adjust the shape, diameter and optical axis direction of the filtered femtosecond laser thermal pulse to obtain an adjusted femtosecond laser thermal pulse;

[0034] The objective lens is used to converge the beam energy of the adjusted femtosecond laser thermal pulse to obtain a converged femtosecond laser thermal pulse.

[0035] In some embodiments, the CoFeB nanodisk comprises a top layer, a free layer and a tunnel barrier layer, the top surface of the free layer is covered with the top layer, and the bottom surface of the free layer is covered with the tunnel barrier layer, wherein:

[0036] The top layer is used to generate electron spin polarization and optimize magnetic anisotropy;

[0037] The free layer is used to form and control magnetic skyrmions;

[0038] The tunnel barrier layer is used to enhance electron spin polarization.

[0039] In some embodiments, the temperature sensor is an infrared temperature sensor, which detects the temperature of a preset area of ​​the CoFeB nanodisk in a non-contact manner.

[0040] The embodiments of the present application include at least the following beneficial effects: The present application provides a method for forming magnetic skyrmions based on femtosecond laser pulse regulation and a writing device. The scheme places a CoFeB nanodisk in a sample placement area of ​​a magneto-optical Kerr effect microscope, and then adjusts the femtosecond laser thermal pulse to pulse-excite the CoFeB nanodisk, controls the generation and annihilation of skyrmions in a preset area of ​​the CoFeB nanodisk, and adjusts the state and number of skyrmions in the CoFeB nanodisk by local femtosecond laser thermal pulses. According to different application requirements, the generation, annihilation and movement of skyrmions can be controlled by changing the parameters of the femtosecond laser thermal pulse, thereby reducing energy consumption and avoiding interference from external noise, thereby improving the ability to accurately control the number and position of skyrmions. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a flow chart of a method for forming magnetic skyrmions based on femtosecond laser pulse regulation provided in an embodiment of the present application;

[0042] Figure 2 is a schematic diagram of the initial skyrmions in the CoFeB nanodisc provided in the embodiment of the present application;

[0043] Figure 3 is a schematic diagram of the change in skyrmion configuration after a femtosecond laser thermal pulse is applied as provided in an embodiment of the present application;

[0044] Figure 4 is a schematic diagram of a nanodisc multilayer film structure provided in an embodiment of the present application;

[0045] Figure 5It is a schematic diagram of the structure of the femtosecond laser pulser provided in the embodiment of the present application.

[0046] Figure numerals: 1. femtosecond laser; 2. first lens; 3. aperture; 4. second lens; 5. polarizer; 6. third lens; 7. objective lens; 8. nanodisk. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. They are only examples of systems and methods consistent with some aspects of the embodiments of the present application as detailed in the attached claims.

[0048] It is understood that the terms "first", "second", etc. used in this application can be used to describe various concepts in this article, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another concept. For example, without departing from the scope of the embodiment of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein can be interpreted as "at the time of" or "when" or "in response to determination".

[0049] The terms "at least one", "multiple", "each", "any", etc. used in this application, at least one includes one, two or more, multiple includes two or more, each refers to each of the corresponding multiple, and any refers to any one of the multiple.

[0050] 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 are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0051] Reference Figure 1 , Figure 1 A flowchart of a method for forming magnetic skyrmions based on femtosecond laser pulse regulation provided by an embodiment of the present invention, referring to Figure 1 , the method comprises the following steps:

[0052] S100, obtaining a CoFeB nanodisk and placing it in a sample placement area of ​​a magneto-optical Kerr effect microscope;

[0053] S200, pulse excitation of the CoFeB nanodisk by adjusting a femtosecond laser thermal pulse, controlling the generation and annihilation of skyrmions in a preset area of ​​the CoFeB nanodisk, and obtaining the number and position of skyrmions;

[0054] In some embodiments, step S200 may include: S210, adjusting the femtosecond laser thermal pulse according to a preset thermal excitation condition; S220, pulse exciting a preset area of ​​the CoFeB nanodisk according to the adjusted femtosecond laser thermal pulse to control the generation and annihilation of skyrmions of the CoFeB nanodisk in the preset area; S230, determining the number and position of skyrmions according to the generation and annihilation of skyrmions.

[0055] Furthermore, it should be noted that, in some specific embodiments, the preset thermal excitation conditions include a pulse temperature range, a pulse duration, and a pulse number, wherein the pulse temperature range is used to control the generation and annihilation of skyrmions of CoFeB nanodisks in a preset area; the pulse duration and the pulse number are used to achieve the response and control of skyrmions of CoFeB nanodisks in a preset area.

[0056] Among them, the femtosecond laser thermal pulse generator is a laser heat source used to transfer heat to a specific area of ​​the CoFeB nanodisk by optical methods. The peak temperature range of the femtosecond laser thermal pulse is 300K to 2000K to meet the needs of different skyrmion generation and annihilation. The duration of the femtosecond laser thermal pulse is 10 picoseconds to achieve rapid response and precise control of skyrmions, and the spatial range of the local thermal pulse is a specific area of ​​the CoFeB nanodisk to ensure the generation or annihilation of skyrmions at the designated location.

[0057] Furthermore, it should be noted that the pulse temperature range includes a first preset pulse temperature range and a second preset pulse temperature range, the first preset pulse temperature range is larger than the second preset pulse temperature range, wherein the first preset pulse temperature range is used to control the generation of skyrmions of CoFeB nanodisks in a preset area; and the second preset pulse temperature range is used to control the annihilation of skyrmions of CoFeB nanodisks in a preset area.

[0058] The number and distribution of skyrmions are controlled by adjusting the peak temperature and duration of the femtosecond laser thermal pulse. The high temperature pulse (400K to 2000K), i.e., the first preset pulse temperature range, is used to generate skyrmions, and the low temperature pulse (300K to 400K), i.e., the second preset pulse temperature range, is used to annihilate skyrmions.

[0059] S300, writing and reading data according to the generation and annihilation of skyrmions and the number and position of skyrmions;

[0060] It should be noted that in some embodiments, when writing data, thermal pulses of different temperatures and durations are applied to the CoFeB nanodisk to change the generation or annihilation of skyrmions in a specific area to adjust the distribution and number of skyrmions in the nanodisk; when reading data, the storage state is identified by detecting the number and position of skyrmions.

[0061] In summary, the embodiment of the present invention first selects Ta / CoFeB / MgO multilayer film as a sample, and further places the sample in the sample placement area of ​​the magneto-optical Kerr effect microscope, such as Figure 2 As shown, a femtosecond laser pulse source is connected, and the output power, pulse frequency and duration of the laser are adjusted to generate a controllable heating pulse, wherein the peak temperature and duration range of the laser are set to ensure that different temperatures and heating durations can be applied in the experiment. Specifically, the temperature range of the femtosecond laser pulse is set by the software (from 300k to 2000K). Different pulse durations are set to 10 picoseconds and the number of pulses is set to 50 times to simulate different thermal excitation conditions. After each pulse is applied, the changes in the number, morphology and distribution of skyrmions are observed in real time, and all experimental parameters, including laser pulse conditions, number of skyrmions, magnetic domain changes, etc., are recorded to facilitate subsequent data analysis. According to different application requirements, the generation, annihilation and movement of skyrmions are controlled by changing the parameters of the femtosecond laser thermal pulse, such as Figure 3 As shown, the application method and parameters of the femtosecond laser thermal pulse can achieve precise control of the skyrmion state in the CoFeB nanodisk.

[0062] The embodiment of the present application also provides a magnetic skyrmion writing device based on femtosecond laser pulse regulation, which can realize the above-mentioned magnetic skyrmion formation method based on femtosecond laser pulse regulation. The device includes a femtosecond laser pulser, a CoFeB nanodisk and a temperature sensor. The central axis of the femtosecond laser pulser and the center of the CoFeB nanodisk are on the same straight line, and the temperature sensor and the CoFeB nanodisk are connected in a non-contact manner, wherein:

[0063] The femtosecond laser pulser is used to emit femtosecond laser heat pulses;

[0064] Specifically, the femtosecond laser pulser includes a femtosecond laser, a first lens, an aperture, a second lens, a polarizer, a third lens and an objective lens, wherein the first lens, the aperture, the second lens, the polarizer, the third lens and the objective lens are placed in sequence along the direction of the femtosecond laser thermal pulse emitted by the femtosecond laser, wherein the femtosecond laser is used to generate a femtosecond laser thermal pulse; the first lens is used to collimate and focus the femtosecond laser thermal pulse to obtain a focused femtosecond laser thermal pulse; the aperture is used to adjust the cross-sectional diameter and shape of the focused femtosecond laser thermal pulse to obtain an adjusted femtosecond laser thermal pulse; the second lens is used to optimize the beam energy density distribution of the adjusted femtosecond laser thermal pulse to obtain an optimized femtosecond laser thermal pulse; the polarizer is used to filter the optimized femtosecond laser thermal pulse to obtain a filtered femtosecond laser thermal pulse; the third lens is used to adjust the shape, diameter and optical axis direction of the filtered femtosecond laser thermal pulse to obtain an adjusted femtosecond laser thermal pulse; the objective lens is used to converge the beam energy of the adjusted femtosecond laser thermal pulse to obtain a converged femtosecond laser thermal pulse.

[0065] In this embodiment, a femtosecond laser thermal pulse generator is used to apply a thermal pulse to a specific area within a CoFeB nanodisk of a Ta / CoFeB / MgO multilayer film structure; the laser emitted by the femtosecond laser thermal pulse generator is emitted to the CoFeB nanodisk, and the temperature peak value and duration of the thermal pulse are adjusted to control the number and state of skyrmions.

[0066] More specifically, Figure 5 As shown, the femtosecond laser 1 is used to generate a femtosecond pulse light source. The optical pulse width is usually between tens of femtoseconds and hundreds of femtoseconds, providing a light source with high peak power and high coherence, which is suitable for studying ultrafast dynamic processes and nonlinear optical effects. High transient energy density can instantaneously induce non-equilibrium processes in materials, such as electron excitation, local heating, non-thermal electron dynamics, etc. The output light usually has a wide spectrum, with a central wavelength in the near-infrared (such as 800nm) or other ranges. The laser directly outputs pulsed light, and the light beam is processed by a subsequent optical system, including spatial shaping, energy regulation, focusing, etc.

[0067] The first lens 2 is used to collimate or preliminarily focus the light beam output from the laser to ensure the effective use of subsequent optical devices. If the light beam diverges, the lens will collimate the light beam to make it parallel. If the spot size needs to be adjusted, the lens can preliminarily change the beam diameter to optimize the subsequent energy distribution. The lens material needs to match the laser wavelength, and materials with high transmittance (such as fused quartz) are often selected. The radius of curvature and focal length are precisely selected according to the specific laser parameters and device design. The collimated or focused light beam enters the aperture for further light beam screening.

[0068] Aperture 3 is used to limit the spatial range of the beam and adjust the cross-sectional diameter and shape of the beam. Function: Remove low-quality light at the edge of the laser beam and improve the uniformity of the beam. Ensure that the beam size matches the size of subsequent optical components (such as lenses and polarizers); the aperture shape (such as round, square) can be selected according to experimental requirements, and an adjustable aperture is often used to flexibly adjust the diameter.

[0069] The second lens 4 is used to further expand or focus the light beam after the aperture to optimize the energy density distribution of the light beam. The diameter of the light beam is changed to adjust the light intensity distribution. The wavefront of the light beam is corrected to provide higher quality light for the polarizer. The configuration is designed in coordination with Lens 1, and the overall optical path length and beam shape requirements must be considered. The adjusted light beam is transmitted to the polarizer for polarization control.

[0070] The polarizer 5 is used to selectively filter the polarization state of the light beam and optimize the polarization direction to adapt to the requirements of subsequent experiments. Output linearly polarized light and enhance the interaction effect between the laser and the material by adjusting the polarization direction. Improve the directionality and coherence of the light beam and reduce optical noise. The polarizer material is usually made of highly transparent and highly polarization-selective materials (such as polarizing films or prisms), and the position and angle need to be precisely adjusted to match the requirements of the objective lens and the sample. The adjusted polarized light beam is transmitted to the objective lens for final focusing.

[0071] The third lens 6 is used to adjust the beam shape, diameter and optical axis direction to ensure that the laser beam is evenly and accurately transmitted to the objective lens to achieve the best focusing effect.

[0072] The objective lens 7 is used to finally focus the laser beam and concentrate the beam energy on the target area (such as the surface of the nanodisk). It provides extremely high energy density, and the focused spot is usually smaller than the micron level to achieve ultra-high spatial resolution energy transfer. It induces thermal effects, electronic excitation or magnetic changes on the surface of the target material. Lenses with high numerical aperture (NA) are often used to achieve the smallest focused spot. The lens surface needs to have an anti-reflection coating to reduce laser energy loss. The focused laser directly acts on the target sample (nanodisk).

[0073] Nanodisc 8, Ta / CoTeB / MgO multilayer film structure is selected as the target material for laser action to study physical processes such as laser-induced thermal effect and magnetic regulation. Femtosecond laser produces local heating and ultrafast dynamic effects in the tiny area of ​​the nanodisc. It may induce complex magnetic changes such as domain wall motion, skyrmion formation or annihilation.

[0074] CoFeB nanodisks are used to control skyrmion generation and annihilation based on femtosecond laser thermal pulses;

[0075] Specifically, the CoFeB nanodisk includes a top layer, a free layer and a tunnel barrier layer. The upper surface of the free layer is covered with the top layer, and the lower surface of the free layer is covered with the tunnel barrier layer. The top layer is used to generate electron spin polarization and optimize magnetic anisotropy; the free layer is used to form and control magnetic skyrmions; and the tunnel barrier layer is used to enhance electron spin polarization.

[0076] In this embodiment, if Figure 4 As shown, the top layer of Ta has high stability and oxidation resistance and is used as a protective layer to prevent the CoFeB layer from oxidizing and enhance the structural stability. Tantalum plays a key role in the interface quality between the magnetic layer (such as CoFeB) and the non-magnetic layer, optimizing magnetic properties such as spin polarization and magnetic anisotropy.

[0077] The middle layer, CoFeB (cobalt iron boron), is a free layer used to form and control magnetic skyrmions. Its magnetic properties can be precisely adjusted by external stimuli (such as lasers, temperature fields). It has high saturation magnetization (Ms) and low magnetic anisotropy, making it suitable for use as the working layer of nanomagnetic devices. CoFeB is a magnetic material commonly used in spintronics MRAM, which can support the transmission of spin-polarized current. By adjusting the thickness or interface quality, the anisotropy of the magnetic layer can be regulated, thereby affecting the stability of the magnetic state. CoFeB is sensitive to femtosecond laser-induced thermal effects and is an ideal material for studying temperature-regulated magnetic properties. The CoFeB / MgO interface can produce a strong interface DMI, which is conducive to the formation of stable skyrmion nanostructures, that is, the magnetic material is a CoFeB film with perpendicular magnetic anisotropy, which supports the formation and control of skyrmions through its spin structure properties.

[0078] The bottom layer, MgO (magnesium oxide), acts as a tunnel barrier layer, providing enhancement of the interfacial electron spin polarization for the magnetic tunnel junction (MTJ). In addition, it supports perpendicular magnetic anisotropy (PMA), stabilizing the formation of skyrmions. It is an electrical insulator, has high thermal stability, and is well matched with CoFeB to form an interface effect.

[0079] The temperature sensor is used to detect the temperature of the femtosecond laser thermal pulse.

[0080] The temperature sensor is an infrared temperature sensor, which detects the temperature of a preset area of ​​the CoFeB nanodisk in a non-contact manner.

[0081] In this embodiment, the temperature sensor is placed in the vicinity of the CoFeB nanodisk to monitor the temperature of the femtosecond laser thermal pulse area in real time to ensure the skyrmion stability and control accuracy.

[0082] In summary, the Ta / CoFeB / MgO film in the embodiment of the present invention is deposited on the substrate by magnetron sputtering technology. During the sputtering process, the film is provided with perpendicular magnetic anisotropy by controlling parameters such as atmosphere, temperature and power, so as to support the formation of skyrmions. After the film deposition is completed, the CoFeB film is patterned by electron beam lithography technology, and then ion beam etching is performed to form a disk structure with a diameter of 100 nanometers to 1 micron to ensure the structural accuracy. After the disk structure is prepared, the thermal pulse control device is installed in place. The device includes a laser heat source and a temperature monitoring module. The laser is used to generate local heat pulses, and the temperature sensor is used for real-time monitoring to ensure the stability of the temperature.

[0083] It can be understood that the contents of the above method embodiments are all applicable to the present system embodiments, the functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0084] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the present invention should be within the scope of the rights of the present invention.

Claims

1. A method for forming magnetic skyrmions based on femtosecond laser pulse regulation, characterized in that: The method comprises the following steps: Obtain the CoFeB nanodisk and place it in the sample placement area of ​​the magneto-optical Kerr effect microscope; By adjusting a femtosecond laser thermal pulse to pulse excite the CoFeB nanodisk, the generation and annihilation of skyrmions in a preset area of ​​the CoFeB nanodisk are controlled, and the number and position of skyrmions are obtained; Data is written and read according to the generation and annihilation of the skyrmions and the number and position of the skyrmions.

2. The method according to claim 1, characterized in that The method of pulse-exciting the CoFeB nanodisk by adjusting a femtosecond laser thermal pulse, controlling the generation and annihilation of skyrmions in a preset area of ​​the CoFeB nanodisk, and obtaining the number and position of skyrmions includes: According to the preset thermal excitation conditions, adjusting the femtosecond laser thermal pulse; Performing pulse excitation on a preset area of ​​the CoFeB nanodisk according to the adjusted femtosecond laser thermal pulse to control the generation and annihilation of skyrmions in the preset area of ​​the CoFeB nanodisk; According to the generation and annihilation of skyrmions, the number and position of skyrmions are determined.

3. The method according to claim 2, characterized in that The preset thermal excitation conditions include pulse temperature range, pulse duration and pulse number, wherein: The pulse temperature range is used to control the generation and annihilation of skyrmions in the CoFeB nanodisk in a preset area; The pulse duration and the pulse number are used to achieve the response and control of the skyrmions in the CoFeB nanodisk in a preset area.

4. The method according to claim 3, characterized in that The pulse temperature range includes a first preset pulse temperature range and a second preset pulse temperature range, the first preset pulse temperature range is greater than the second preset pulse temperature range, wherein: The first preset pulse temperature range is used to control the generation of skyrmions of the CoFeB nanodisk in a preset area; The second preset pulse temperature range is used to control the annihilation of skyrmions of the CoFeB nanodisk in a preset area.

5. The method according to claim 2, characterized in that: The femtosecond laser heat pulse transmits heat to the preset area of ​​the CoFeB nanodisk by an optical method, and the spatial range of the femtosecond laser heat pulse is equal to the spatial range of the preset area of ​​the CoFeB nanodisk.

6. The method according to claim 1, characterized in that The writing and reading of data according to the generation and annihilation of the skyrmions and the number and position of the skyrmions comprises: Writing data through the generation and annihilation of the skyrmions; The data is read out based on the number and position of the skyrmions.

7. A magnetic skyrmion writing device based on femtosecond laser pulse regulation, characterized in that: The device comprises a femtosecond laser pulser, a CoFeB nanodisk and a temperature sensor, wherein the central axis of the femtosecond laser pulser and the center of the CoFeB nanodisk are on the same straight line, and the temperature sensor is connected to the CoFeB nanodisk in a non-contact manner, wherein: The femtosecond laser pulser is used to emit femtosecond laser thermal pulses; The CoFeB nanodisk is used to control the generation and annihilation of skyrmions according to the femtosecond laser thermal pulse; The temperature sensor is used to detect the temperature of the femtosecond laser thermal pulse.

8. The device according to claim 7, characterized in that The femtosecond laser pulser comprises a femtosecond laser, a first lens, an aperture, a second lens, a polarizer, a third lens and an objective lens, wherein the first lens, the aperture, the second lens, the polarizer, the third lens and the objective lens are sequentially placed along the direction of the femtosecond laser thermal pulse emitted by the femtosecond laser, wherein: The femtosecond laser is used to generate the femtosecond laser thermal pulse; The first lens is used to collimate and focus the femtosecond laser thermal pulse to obtain a focused femtosecond laser thermal pulse; The aperture is used to adjust the cross-sectional diameter and shape of the focused femtosecond laser thermal pulse to obtain an adjusted femtosecond laser thermal pulse; The second lens is used to perform beam energy density distribution optimization processing on the adjusted femtosecond laser thermal pulse to obtain an optimized femtosecond laser thermal pulse; The polarizer is used to filter the optimized femtosecond laser thermal pulse to obtain a filtered femtosecond laser thermal pulse; The third lens is used to adjust the shape, diameter and optical axis direction of the filtered femtosecond laser thermal pulse to obtain an adjusted femtosecond laser thermal pulse; The objective lens is used to converge the beam energy of the adjusted femtosecond laser thermal pulse to obtain a converged femtosecond laser thermal pulse.

9. The device according to claim 7, characterized in that The CoFeB nanodisk comprises a top layer, a free layer and a tunnel barrier layer, wherein the upper surface of the free layer is covered with the top layer, and the lower surface of the free layer is covered with the tunnel barrier layer, wherein: The top layer is used to generate electron spin polarization and optimize magnetic anisotropy; The free layer is used to form and control magnetic skyrmions; The tunnel barrier layer is used to enhance electron spin polarization.

10. The device according to claim 7, characterized in that The temperature sensor is an infrared temperature sensor, which detects the temperature of a preset area of ​​the CoFeB nanodisk in a non-contact manner.

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