A method and apparatus for exciting terahertz magnons by an electric field

Abstract

The application provides a method and device for exciting terahertz magnons by electric field. The method comprises the following steps: in a pre-constructed magnon generator, an electric field is applied to the magnon generator, and a voltage is instantaneously jumped from a first value to a second value; during the jump, a domain wall region in the magnon generator excites a THz spin wave which is centered on the domain wall and symmetrically propagates to both sides. The application excites a THz spin wave in the domain wall region by applying a non-continuous electric field to the magnon generator, thereby avoiding the risk of thermal damage caused by high-energy laser or large current, and realizing low-energy consumption and high efficiency of excitation. In addition, due to the high controllability and easy local modulation of the electric field regulation mode, the technology can realize dynamic regulation of the frequency and amplitude of the magnon, thereby providing a new method which is simple, reliable and efficient for the integration and design of high-frequency spin electronic devices.

Description

Technical Field

[0001] This invention relates to the field of terahertz emission technology, and in particular to a method and apparatus for exciting terahertz magnetons by an electric field. Background Technology

[0002] In recent years, with the continuous deepening of research on spintronics and antiferromagnetic materials, the technology of exciting terahertz (THz) magnets has become an important research direction for high-frequency electronic devices and novel information storage technologies. Existing techniques for exciting magnets mainly include optical excitation, spin-orbit-torque (SOT) excitation, and magnetic field pulse excitation, among other mainstream techniques.

[0003] Among them, the optical excitation method uses ultrafast laser pulses to directly excite the spin dynamics inside the material, which can achieve fast response at the picosecond or even femtosecond level. However, the laser equipment required is expensive and complex, and the non-uniform distribution of laser energy in the material may cause local overheating or damage, which poses a considerable challenge to device integration and large-scale application.

[0004] Spin-orbit torque excitation technology drives a micromagnetic structure into a relativistic state by injecting a large current, thereby exciting THz magnets. This method offers advantages in localized control, but it requires high-quality material interfaces and a very high current density, which can easily damage the device itself. More commonly used in the ferromagnetic field is the excitation of GHz magnets via spin-orbit torque.

[0005] Thermal excitation, a method that has attracted widespread attention in recent years, induces spin wave excitation through local temperature gradients or instantaneous heating. It can achieve rapid response without additional lasers or magnetic fields and has a simple structure. However, thermal excitation is often accompanied by high energy consumption and thermal noise problems, and it cannot generate coherent spin waves, making dynamic control difficult.

[0006] To address the above problems, this invention proposes a method and apparatus for exciting terahertz magnetons by an electric field, which can dynamically control the generation of coherent spin waves, is easy to integrate, and has low energy consumption. Summary of the Invention

[0007] This invention provides a method and apparatus for exciting terahertz magnetic particles by an electric field, which solves the defects of existing THz magnetic particle excitation equipment such as complexity, high energy consumption, and lack of effective dynamic control.

[0008] This invention provides a method for exciting terahertz magnetons by an electric field, comprising:

[0009] An electric field is applied to the magneton generator, causing the voltage of the applied electric field to jump instantaneously from a first voltage value V1 to a second voltage value V2.

[0010] During the instantaneous voltage jump from V1 to V2, the domain wall region in the magneton generator directly excites a terahertz spin wave that propagates symmetrically in both directions around the domain wall.

[0011] According to the present invention, a method for exciting terahertz magnetic particles by an electric field is provided, wherein the magnetic particle generator comprises, from bottom to top, a heavy metal layer, an antiferromagnetic layer and an electrode layer;

[0012] The heavy metal layer is metal Pt or Ta, the antiferromagnetic layer is antiferromagnetic material NiO or α-Fe2O3, and the electrode layer is conductor material Au.

[0013] If the antiferromagnetic layer is an antiferromagnetic metal material, an insulating layer is provided between the antiferromagnetic layer and the electrode layer, and the insulating layer is MgO;

[0014] The positive terminal of the power supply is connected to the heavy metal layer, and the negative terminal of the power supply is connected to the electrode layer.

[0015] According to a method for exciting terahertz magnetons by an electric field provided by the present invention, the magnetic anisotropy constant and / or Dzyaloshinskii–Moriya interaction constant in the antiferromagnetic layer are abruptly changed from a first value to a second value to simulate the effect produced by applying an electric field to the magneton generator.

[0016] According to the present invention, a method for exciting terahertz magnetons by an electric field further includes, before applying an electric field to the magneton generator:

[0017] The temporal evolution of independent spins in the antiferromagnetic layer is described based on the Landau-Lifshitz-Gilbert equations.

[0018] The Landau-Lifshitz-Gilbert equation was numerically solved using the fourth-order Runge-Kutta method to obtain the stable initial state of the antiferromagnetic layer and the well-defined domain wall structure.

[0019] According to the method for exciting terahertz magnetons by an electric field provided by the present invention, after exciting a terahertz spin wave centered on the domain wall and propagating symmetrically in both directions in the domain wall region of the magneton generator, the method further includes:

[0020] Real-time monitoring of the position and width of magnetic domain walls and the temporal evolution of each magnetic moment component;

[0021] Fourier transform spectrum analysis was performed on the terahertz spin wave to extract the main frequency components and amplitude of the terahertz spin wave.

[0022] According to the present invention, a method for exciting terahertz magnetons by an electric field further includes, before the magnetic anisotropy constant and / or Dzyaloshinskii–Moriya interaction constant in the simulated antiferromagnetic layer abruptly change from a first value to a second value:

[0023] The first mapping curve between the terahertz spin wave frequency and the difference between the magnetic anisotropy constant before and after the abrupt change was obtained through simulation.

[0024] The second mapping curve between the terahertz spin wave frequency and the difference between the Dzyaloshinskii–Moriya interaction constant before and after the abrupt change was obtained through simulation.

[0025] The target terahertz spin wave frequency is mapped to the first mapping curve and / or the second mapping curve to determine the difference before and after the abrupt change in the magnetic anisotropy constant and / or the difference before and after the abrupt change in the Dzyaloshinskii–Moriya interaction constant corresponding to the target terahertz spin wave frequency.

[0026] According to the present invention, a method for exciting terahertz magnetons by an electric field further includes, before the magnetic anisotropy constant and / or Dzyaloshinskii–Moriya interaction constant in the simulated antiferromagnetic layer abruptly change from a first value to a second value:

[0027] The third mapping curve between the terahertz spin wave amplitude and the difference before and after the abrupt change in the magnetic anisotropy constant was obtained through simulation.

[0028] The fourth mapping curve between the terahertz spin wave amplitude and the difference between the Dzyaloshinskii–Moriya interaction constant before and after the abrupt change was obtained through simulation.

[0029] Extract the difference in magnetic anisotropy constant before and after the abrupt change corresponding to the amplitude peak from the third mapping curve;

[0030] Extract the difference between the amplitude peak and the abrupt change in the Dzyaloshinskii–Moriya interaction constant before and after the abrupt change from the fourth mapping curve.

[0031] The present invention also provides a device for exciting terahertz magnetons by an electric field, comprising:

[0032] Magneton generator;

[0033] A voltage module is used to apply an electric field to the magneton generator, wherein the voltage instantaneously changes from a first value V1 to a second value V2;

[0034] During the instantaneous voltage jump from V1 to V2, the magnetic domain wall region of the magneton generator directly excites a terahertz spin wave that propagates symmetrically in both directions around the domain wall.

[0035] According to the present invention, a device for exciting terahertz magnets by an electric field is provided, wherein the magnet generator comprises, from bottom to top, a heavy metal layer, an antiferromagnetic layer and an electrode layer;

[0036] The heavy metal layer is metal Pt or Ta, the antiferromagnetic layer is antiferromagnetic material NiO or α-Fe2O3, and the electrode layer is conductor material Au.

[0037] If the antiferromagnetic layer is an antiferromagnetic metal material, an insulating layer is provided between the antiferromagnetic layer and the electrode layer, and the insulating layer is MgO;

[0038] The positive terminal of the power supply is connected to the heavy metal layer, and the negative terminal of the power supply is connected to the electrode layer.

[0039] According to the present invention, a device for exciting terahertz magnetons by an electric field is provided, wherein the effect generated by the magneton generator applying the electric field is achieved by simulating the following: causing the magnetic anisotropy constant and / or the Dzyaloshinskii–Moriya interaction constant in the antiferromagnetic layer to abruptly change from a first value to a second value.

[0040] The present invention provides a method and apparatus for electric field-induced THz magnets. By applying a discontinuously varying electric field to a magnet generator, THz spin waves propagate symmetrically to both sides of the domain wall region. Compared with traditional excitation methods, this embodiment not only avoids the risk of thermal damage caused by high-energy lasers or high currents, but also achieves low-energy consumption and high-efficiency excitation. Furthermore, due to the highly controllable and easily localized characteristics of the electric field modulation method, this technology enables dynamic control of the magnet frequency and amplitude, thus providing a simpler, more reliable, and more efficient new method for the design and implementation of high-frequency spintronic devices. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 This is a schematic flowchart of the method for exciting THz magnets by electric field provided by the present invention;

[0043] Figure 2 This is a schematic diagram of the model structure of the electric field-excited THz magnets in the method for electric field-excited THz magnets provided by the present invention;

[0044] Figure 3 This is a schematic diagram showing the jump of the magnetic anisotropy constant K and the Dzyaloshinskii–Moriya interaction constant D with the applied voltage in the method of electric field excitation of THz magnetons provided by the present invention.

[0045] Figure 4 This is an FFT diagram showing the oscillation mapping curve of the x component of the Nell vector at a specific location in the magnetic domain region over time due to the jump in the magnetic anisotropy constant K in the electric field-excited THz magneton method provided by the present invention.

[0046] Figure 5 This is an FFT diagram illustrating the oscillation mapping curve of the x component of the Nell vector at a specific location in the magnetic domain region over time caused by the jump in the Dzyaloshinskii–Moriya interaction constant D in the electric field-excited THz magneton method provided by this invention.

[0047] Figure 6 This is a schematic diagram of the mapping curve of the magnetic particle frequency with ΔK in the method for exciting THz magnetic particles by electric field provided by the present invention;

[0048] Figure 7 This is a schematic diagram of the mapping curve of the magnetic particle frequency with ΔD in the method for exciting THz magnetic particles by electric field provided by the present invention;

[0049] Figure 8 This is a schematic diagram illustrating the variation of magneton amplitude with ΔK in the method for exciting THz magnetons using an electric field provided by the present invention.

[0050] Figure 9 This is a schematic diagram showing the variation of the amplitude of a magneton with ΔD in the method for exciting THz magnetons by an electric field provided by the present invention.

[0051] Figure 10 This is a schematic diagram illustrating how, in the method for exciting THz magnetons using an electric field provided by this invention, when the difference between the first and second values ​​of the Dzyaloshinskii–Moriya interaction strength is large, magneton scattering is enhanced, generating a frequency-doubled magneton signal. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0053] The following is combined Figure 1 A method for exciting terahertz magnetons by an electric field according to the present invention includes:

[0054] Step 101: Apply an electric field to the magneton generator, causing the voltage of the applied electric field to jump instantaneously from the first voltage value V1 to the second voltage value V2;

[0055] Step 102: During the instantaneous voltage jump from V1 to V2, the domain wall region in the magneton generator directly excites a terahertz spin wave that propagates symmetrically in both directions around the domain wall.

[0056] This embodiment applies a discontinuously varying electric field to a magnet generator, thereby exciting THz spin waves that propagate symmetrically to both sides of the domain wall region. Compared with traditional excitation methods, this embodiment not only avoids the risk of thermal damage caused by high-energy lasers or high currents, but also achieves low-energy-consumption and high-efficiency excitation. Furthermore, due to the highly controllable and easily localized characteristics of the electric field modulation method, this technology enables dynamic control of the magnet frequency and amplitude, thus providing a simpler, more reliable, and more efficient new approach for the design and implementation of high-frequency spintronic devices.

[0057] Based on the above embodiments, such as Figure 2 As shown, the magneton generator in this embodiment includes, from bottom to top, a heavy metal layer, an antiferromagnetic layer, and an electrode layer;

[0058] The heavy metal layer is Pt, Ta, etc., the antiferromagnetic layer is NiO, α-Fe2O3, etc., and the electrode layer is Au, etc., a conductor material.

[0059] If the antiferromagnetic layer is made of an antiferromagnetic metal material, an insulating layer, such as MgO, needs to be added between the antiferromagnetic layer and the electrode layer.

[0060] The positive terminal of the power supply is connected to the heavy metal layer, and the negative terminal of the power supply is connected to the electrode layer.

[0061] Based on the above embodiments, in this embodiment, the magnetic anisotropy constant and / or Dzyaloshinskii–Moriya interaction constant in the antiferromagnetic layer are abruptly changed from a first value to a second value to simulate the effect produced by applying an electric field to the magneton generator.

[0062] To simulate the effect of an applied electric field on magnetic parameters, this embodiment does not directly apply an electric field. Instead, it employs an equivalent method: after the system reaches equilibrium, the magnetic anisotropy constant K and the Dzyaloshinskii–Moriya interaction constant D are instantaneously and discontinuously adjusted. Specifically, the magnetic anisotropy constant is abruptly changed from its initial value K0 to K1, and the Dzyaloshinskii–Moriya interaction constant is abruptly changed from D0 to D1 (e.g., ...). Figure 3 As shown in the figure, the changes in the internal magnetic parameters of an antiferromagnetic material under the action of an electric field are simulated. The changes in the material's magnetic parameters are proportional to the electric field.

[0063] This mutation triggers a rapid response in the domain wall spin structure, thereby exciting THz spin waves that propagate bidirectionally around the domain wall. The core mechanism is that when an external electric field is applied to an antiferromagnetic material, it can change the energy state and structure of the domain wall, triggering magnetic excitation in the domain wall region and emitting terahertz (THz) spin waves to both sides of the domain wall.

[0064] To facilitate numerical simulation, this embodiment uses the instantaneous abrupt change of the magnetic anisotropy constant K and / or the Dzyaloshinskii–Moriya interaction constant D to equivalently simulate the electromagnetic effect. However, in actual devices, this effect is directly achieved through an external electric field, thereby realizing low-power, high-efficiency THz spin wave excitation.

[0065] This embodiment utilizes the abrupt change in the magnetic anisotropy constant and / or the Dzyaloshinskii–Moriya interaction constant as an equivalent means to simulate the electric field effect, thereby achieving the excitation of THz-band spin waves at magnetic domain walls in antiferromagnetic materials. This technique not only provides an efficient and controllable THz magneton excitation mechanism but also offers new ideas and theoretical foundations for the design and implementation of high-frequency spintronic devices and magneton chips.

[0066] Based on the above embodiments, this embodiment further includes the following step before applying an electric field to the magneton generator:

[0067] The time evolution of a single spin in the antiferromagnetic layer is described using the LLG (Landau-Lifshitz-Gilbert) equations.

[0068] The LLG equations were numerically solved using the fourth-order Runge-Kutta (RK4) method to obtain the stable initial state and well-defined domain wall structure of the antiferromagnetic layer.

[0069] The basic form of the LLG equation is:

[0070]

[0071] in, The normalized spin vector is γ, the gyromagnetic ratio is α, and the Gilbert damping coefficient is τ. D For SOT type damping moment, τ F For SOT type field moments, H eff The effective field includes contributions from various sources such as exchange interaction, magnetic anisotropy, Dzyaloshinskii-Moriya interaction (DMI), and dipole interaction.

[0072] The entire numerical simulation process is divided into two main stages. The first stage is the initial relaxation process. By setting the initial magnetic moment distribution and boundary conditions, the LLG equations are numerically solved using the fourth-order Runge-Kutta method to obtain a stable initial state of antiferromagnetic domain walls. The calculations in this stage provide accurate initial conditions for the subsequent dynamic response.

[0073] In the second stage, after the system evolution reaches an equilibrium state, the magnetic anisotropy constant K and the Dzyaloshinskii–Moriya interaction constant D are instantaneously and discontinuously controlled to induce a rapid response of the domain wall spin structure, thereby exciting a THz spin wave that propagates symmetrically to both sides of the domain wall.

[0074] In the numerical solution process, the discretization uses an extremely fine time step Δt and spatial step Δx to ensure high accuracy of the simulation.

[0075] This embodiment is based on the precise numerical solution of atomic spin dynamics in antiferromagnetic materials, and uses instantaneous discontinuous modulation of the magnetic anisotropy constant and / or the Dzyaloshinskii–Moriya interaction constant to equivalently simulate the electric field effect, thereby efficiently exciting spin waves in the THz band within the magnetic domain wall region.

[0076] Based on the above embodiments, this embodiment, after generating a terahertz spin wave centered on the domain wall and propagating symmetrically in both directions in the domain wall region of the magnet generator, further includes:

[0077] Real-time monitoring of the position and width of magnetic domain walls and the temporal evolution of each magnetic moment component;

[0078] Fourier transform spectrum analysis was performed on the terahertz spin wave to extract its main frequency components and amplitude.

[0079] The jumps in the magnetic anisotropy constant K and the Dzyaloshinskii–Moriya interaction constant D cause the FFT diagram of the oscillatory mapping curve of the x-component of the Nell vector at a specific location in the magnetic domain region over time to be shown in the figure. Figure 4 and Figure 5 As shown.

[0080] Based on the above embodiments, this embodiment further includes the following before the magnetic anisotropy constant and / or Dzyaloshinskii–Moriya interaction constant in the simulated antiferromagnetic layer abruptly change from a first value to a second value:

[0081] The first mapping curve between the terahertz spin wave frequency and the difference between the magnetic anisotropy constant before and after the abrupt change was obtained through simulation.

[0082] The second mapping curve between the terahertz spin wave frequency and the difference between the Dzyaloshinskii–Moriya interaction constant before and after the abrupt change was obtained through simulation.

[0083] The target terahertz spin wave frequency is mapped to a first mapping curve and / or a second mapping curve to determine the difference in the magnetic anisotropy constant before and after the abrupt change and the difference in the Dzyaloshinskii–Moriya interaction constant before and after the abrupt change corresponding to the target terahertz spin wave frequency.

[0084] The first mapping curve is as follows: Figure 6 As shown, the second mapping curve is as follows Figure 7 As shown. When assigning the target frequency of a THz spin wave to the first mapping curve and / or the second mapping curve, the entire target frequency of the THz spin wave can be assigned to either the first or second mapping curve, and the difference corresponding to the target frequency of the THz spin wave can be obtained from either the first or second mapping curve. Alternatively, a portion of the target frequency of the THz spin wave can be assigned to the first mapping curve, and another portion to the second mapping curve, with the allocation ratio set as needed. The difference corresponding to the assigned frequency can be obtained from the first and second mapping curves.

[0085] Based on the above embodiments, this embodiment further includes the following before the magnetic anisotropy constant and / or Dzyaloshinskii–Moriya interaction constant in the simulated antiferromagnetic layer abruptly change from a first value to a second value:

[0086] The third mapping curve between the terahertz spin wave amplitude and the difference before and after the abrupt change in the magnetic anisotropy constant was obtained through simulation.

[0087] The fourth mapping curve between the terahertz spin wave amplitude and the difference between the Dzyaloshinskii–Moriya interaction constant before and after the abrupt change was obtained through simulation.

[0088] Extract the difference in magnetic anisotropy constant before and after the abrupt change corresponding to the amplitude peak from the third mapping curve;

[0089] Extract the difference between the amplitude peak and the abrupt change in the Dzyaloshinskii–Moriya interaction constant before and after the abrupt change from the fourth mapping curve.

[0090] The third mapping curve is as follows Figure 8 As shown, the fourth mapping curve is as follows Figure 9 As shown, the amplitude of a THz spin wave is represented by the cone angle of spin precession.

[0091] Figure 10This indicates that when the difference between the first and second values ​​of the Dzyaloshinskii–Moriya interaction constant is large, magneton scattering is enhanced, which will generate frequency-doubled magneton signals that can be used to generate high-frequency magnetons.

[0092] In summary, this invention employs numerical simulation to obtain a stable magnetic ground state through initial relaxation, and then utilizes the discontinuous modulation of the magnetic anisotropy constant and / or the Dzyaloshinskii–Moriya interaction strength to simulate the electric field effect, thereby achieving efficient excitation of THz-band spin waves (magnetons) in antiferromagnetic materials. This approach not only avoids the experimental complexity and thermal effects associated with directly applying high-energy lasers or large currents, but also features low energy consumption, dynamic controllability, high response speed, and good device integration, providing a solid theoretical basis and technical support for the design and application of novel spintronic devices.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for exciting terahertz magnetons by an electric field, characterized in that, include: An electric field is applied to a magneton generator, causing the voltage of the applied electric field to jump instantaneously from a first voltage value V1 to a second voltage value V2. The magneton generator comprises, from bottom to top, a heavy metal layer, an antiferromagnetic layer, and an electrode layer. During the instantaneous voltage jump from V1 to V2, the domain wall region in the magneton generator directly excites a terahertz spin wave that propagates symmetrically in both directions around the domain wall. The magnetic anisotropy constant and / or Dzyaloshinskii–Moriya interaction constant in the antiferromagnetic layer abruptly change from a first value to a second value to simulate the effect produced by applying an electric field to the magneton generator.

2. The method according to claim 1, characterized in that, The heavy metal layer is metal Pt or Ta, the antiferromagnetic layer is antiferromagnetic material NiO or α-Fe2O3, and the electrode layer is conductor material Au. If the antiferromagnetic layer is an antiferromagnetic metal material, an insulating layer is provided between the antiferromagnetic layer and the electrode layer, and the insulating layer is MgO; The positive terminal of the power supply is connected to the heavy metal layer, and the negative terminal of the power supply is connected to the electrode layer.

3. The method according to claim 2, characterized in that, Before applying an electric field to the magneton generator, the following is also included: The temporal evolution of independent spins in the antiferromagnetic layer is described based on the Landau-Lifshitz-Gilbert equations. The Landau-Lifshitz-Gilbert equation was numerically solved using the fourth-order Runge-Kutta method to obtain the stable initial state of the antiferromagnetic layer and the well-defined domain wall structure.

4. The method according to claim 1, characterized in that, After generating terahertz spin waves that propagate bidirectionally symmetrically around the domain walls in the domain wall region of the magnet generator, the process also includes: Real-time monitoring of the position and width of magnetic domain walls and the temporal evolution of each magnetic moment component; Fourier transform spectrum analysis was performed on the terahertz spin wave to extract the main frequency components and amplitude of the terahertz spin wave.

5. The method according to claim 1, characterized in that, Before the magnetic anisotropy constant and / or Dzyaloshinskii–Moriya interaction constant in the simulated antiferromagnetic layer abruptly change from the first value to the second value, the following are also included: The first mapping curve between the terahertz spin wave frequency and the difference between the magnetic anisotropy constant before and after the abrupt change was obtained through simulation. The second mapping curve between the terahertz spin wave frequency and the difference between the Dzyaloshinskii–Moriya interaction constant before and after the abrupt change was obtained through simulation. The target terahertz spin wave frequency is mapped to the first mapping curve and / or the second mapping curve to determine the difference before and after the abrupt change in the magnetic anisotropy constant and / or the difference before and after the abrupt change in the Dzyaloshinskii–Moriya interaction constant corresponding to the target terahertz spin wave frequency.

6. The method according to claim 1, characterized in that, Before the magnetic anisotropy constant and / or Dzyaloshinskii–Moriya interaction constant in the simulated antiferromagnetic layer abruptly change from the first value to the second value, the following are also included: The third mapping curve between the terahertz spin wave amplitude and the difference before and after the abrupt change in the magnetic anisotropy constant was obtained through simulation. The fourth mapping curve between the terahertz spin wave amplitude and the difference between the Dzyaloshinskii–Moriya interaction constant before and after the abrupt change was obtained through simulation. Extract the difference in magnetic anisotropy constant before and after the abrupt change corresponding to the amplitude peak from the third mapping curve; Extract the difference between the amplitude peak and the abrupt change in the Dzyaloshinskii–Moriya interaction constant before and after the abrupt change from the fourth mapping curve.

7. A device for exciting terahertz magnetons by an electric field, characterized in that, include: A magneton generator, comprising, from bottom to top, a heavy metal layer, an antiferromagnetic layer, and an electrode layer; A voltage module is used to apply an electric field to the magneton generator, wherein the voltage instantaneously changes from a first value V1 to a second value V2; During the instantaneous voltage jump from V1 to V2, the magnetic domain wall region of the magneton generator directly excites a terahertz spin wave that propagates symmetrically in both directions around the domain wall. The effect of the electric field applied by the magneton generator is achieved by simulating the following: the magnetic anisotropy constant and / or the Dzyaloshinskii–Moriya interaction constant in the antiferromagnetic layer are abruptly changed from a first value to a second value.

8. The apparatus according to claim 7, characterized in that, The heavy metal layer is metal Pt or Ta, the antiferromagnetic layer is antiferromagnetic material NiO or α-Fe2O3, and the electrode layer is conductor material Au. If the antiferromagnetic layer is an antiferromagnetic metal material, an insulating layer is provided between the antiferromagnetic layer and the electrode layer, and the insulating layer is MgO; The positive terminal of the power supply is connected to the heavy metal layer, and the negative terminal of the power supply is connected to the electrode layer.

Images