Method for measuring exchange coupling between two-dimensional magnetic material layers and system thereof

Abstract

The application discloses a two-dimensional magnetic material interlayer exchange coupling micro-area electrical measurement method and system, and relates to the technical field of characteristic detection. By acquiring target micro-area spatial position coordinate data and current measurement state data, intervention coding data containing magnetic field disturbance direction coding, interlayer differential potential direction coding and cross combination coding is constructed. Based on the intervention coding data, the target micro-area magnetic field state and the interlayer potential disturbance state are adjusted, and corresponding micro-area electrical response data is collected to form coding response matrix data. By projecting and decomposing the coding response matrix data, interlayer exchange related cross response data is extracted, and interlayer exchange coupling parameter data and distinguishable data are generated in combination with a double-layer magnetic moment model. According to the identification result, the measurement state is adjusted to realize the acquisition of micro-area interlayer exchange coupling parameter data. The application can reduce the coupling interference of multiple physical field responses and improve the accuracy of two-dimensional magnetic material micro-area interlayer exchange coupling parameter data measurement.

Description

Technical Field

[0001] This invention relates to the field of characteristic detection technology, specifically to a method and system for measuring the electrical properties of two-dimensional magnetic materials in interlayer exchange-coupled micro-regions. Background Technology

[0002] Currently, research on the interlayer exchange coupling characteristics of two-dimensional magnetic materials typically involves obtaining the response characteristics of the material as a whole or over a large area through macroscopic magnetic measurements, electrical transport tests, or magneto-optical characterization. These methods are then combined with magnetic moment models to analyze the interlayer exchange coupling parameter data, thereby evaluating the magnetic properties of the material.

[0003] However, for two-dimensional magnetic materials, factors such as interlayer structural defects, local strain distribution, interlayer stacking state, and edge effects can lead to differences in the interlayer exchange coupling characteristics between different micro-regions, making it difficult for macroscopic measurement results to accurately reflect the true coupling state of local regions. During micro-region electrical measurements, the electrical response of the target region is usually affected by multiple factors simultaneously, including external magnetic field perturbations, gate voltage modulation, electrode contact state, and intrinsic interlayer coupling. Response signals generated by different physical actions are prone to superposition, causing characteristic responses related to interlayer exchange coupling to be masked by other perturbation responses, thus reducing the accuracy of micro-region interlayer exchange parameter extraction.

[0004] In existing technologies, to improve measurement accuracy, the measurement results are usually corrected by increasing the magnetic field scanning range, adjusting the gate voltage conditions, or combining model fitting methods. These methods can improve the stability of the overall measurement results to a certain extent. However, since they fail to distinguish the coupling response relationship between magnetic field disturbance and interlayer potential modulation, it is difficult to effectively separate the cross-response information generated by different physical factors. As a result, at the microscale of two-dimensional magnetic materials, the identification process of interlayer exchange coupling parameter data is easily affected by non-target response interference, leading to problems such as unstable local measurement results, insufficient reliability of parameter identification, and difficulty in forming an effective quantization mapping between different micro-regions. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and system for measuring the electrical properties of two-dimensional magnetic materials in a micro-region through interlayer exchange coupling.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention discloses a method for electrical measurement of interlayer exchange-coupled micro-regions in two-dimensional magnetic materials, comprising the following steps:

[0008] The spatial coordinates and current measurement status data of the target micro-region are acquired, and multiple sets of intervention coding data are generated, consisting of magnetic field disturbance direction coding and interlayer differential potential direction coding with a predetermined number of bits. Cross-combination coding is generated according to the same-direction or opposite-direction relationship of various coding bits. The magnetic field disturbance direction coding, the interlayer differential potential direction coding and the cross-combination coding satisfy an orthogonal combination relationship.

[0009] The magnetic field state of the target micro-region is changed according to the intervention coding data of each group, and an equal-amplitude and opposite-reverse potential perturbation is applied to the adjacent magnetic layer. The electrical response data of the micro-region is collected synchronously, and the electrical response data of the micro-region is associated with the corresponding intervention coding data to generate the coding response matrix data.

[0010] Based on the magnetic field disturbance direction coding, the interlayer differential potential direction coding, and the cross-combination coding of the two, the coding response matrix data is projected and decomposed to generate interlayer exchange-related cross-response data.

[0011] The interlayer exchange-related cross-response data and the current measurement state data are input into a preset two-layer magnetic moment model to generate interlayer exchange coupling parameter data and its identifiability data;

[0012] The identifiability data is compared with a preset identification threshold. If the preset identification threshold is not reached, at least one of the following is selected to update: magnetic field disturbance amplitude, interlayer differential potential disturbance amplitude, or current measurement state data, based on whether the model residual data exceeds the preset residual threshold and the numerical range of the response amplitude of the interlayer exchange-related cross-response data. The intervention coding data is then regenerated and returned for execution. If the preset identification threshold is reached, the interlayer exchange coupling parameter data is output.

[0013] Secondly, this invention discloses a two-dimensional magnetic material interlayer exchange-coupled micro-region electrical measurement system, using the aforementioned two-dimensional magnetic material interlayer exchange-coupled micro-region electrical measurement method, comprising:

[0014] The measurement and coding generation module is used to acquire the spatial location coordinate data and current measurement status data of the target micro-region, generate multiple sets of intervention coding data consisting of magnetic field disturbance direction coding and interlayer differential potential direction coding with a predetermined number of bits, and generate cross-combination coding according to the same or opposite direction relationship of various coding bits; the magnetic field disturbance direction coding, the interlayer differential potential direction coding and the cross-combination coding satisfy an orthogonal combination relationship.

[0015] The excitation and response acquisition module is used to change the magnetic field state of the target micro-region according to each set of intervention coding data, and apply equal-amplitude and opposite-phase potential perturbations to adjacent magnetic layers, synchronously acquire micro-region electrical response data, associate the micro-region electrical response data with the corresponding intervention coding data, and generate coded response matrix data.

[0016] The cross-response extraction module is used to perform projection decomposition on the encoded response matrix data based on the magnetic field disturbance direction encoding, the interlayer differential potential direction encoding, and the cross-combination encoding of the two, to generate interlayer exchange-related cross-response data.

[0017] The parameter identification module is used to input the interlayer exchange-related cross-response data and the current measurement state data into a preset two-layer magnetic moment model to generate interlayer exchange coupling parameter data and its identifiability data.

[0018] The feedback and displacement control module is used to compare the identifiability data with a preset identification threshold. If the preset identification threshold is not reached, it selects to update at least one of the following based on whether the model residual data exceeds the preset residual threshold and the numerical range of the response amplitude of the interlayer exchange-related cross-response data: the magnetic field disturbance amplitude, the interlayer differential potential disturbance amplitude, or the current measurement state data, and regenerates the intervention coding data and returns it for execution. If the preset identification threshold is reached, it outputs the interlayer exchange coupling parameter data.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. This invention enables electrical responses generated under different physical disturbance conditions to be associated and recorded according to coding relationships, thereby providing a data basis for distinguishing response information from different sources and avoiding the information mixing problem caused by the superposition of magnetic field response, electric potential modulation response and interlayer coupling response during micro-area measurement.

[0021] 2. This invention enables the characteristic response corresponding to interlayer exchange coupling to be extracted from the electrical response of complex micro-regions, thereby improving the targeting of the data acquisition process of interlayer exchange coupling parameters in local regions of two-dimensional magnetic materials and reducing the influence of non-target response factors on the parameter analysis process.

[0022] 3. This invention adjusts the magnetic field disturbance amplitude, interlayer differential potential disturbance amplitude, or current measurement state based on the identifiability data, and re-executes the intervention-coded measurement, so that the measurement process can be optimized based on the current micro-region response state, thereby improving the adaptability of interlayer exchange coupling parameter data measurement under different micro-region conditions. Attached Figure Description

[0023] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts. Wherein:

[0024] Figure 1 This is a flowchart of the steps of the present invention;

[0025] Figure 2 This is a schematic diagram illustrating the working principle of the present invention;

[0026] Figure 3 This is a system module connection diagram of the present invention;

[0027] Figure 4 This is a flowchart of the system modules of the present invention. Detailed Implementation

[0028] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0029] In existing technologies, the measurement of interlayer exchange coupling parameters in two-dimensional magnetic materials largely relies on macroscopic magnetic characterization or single electrical response analysis, making it difficult to simultaneously ensure measurement accuracy and parameter identification capabilities at the microscale. During traditional micro-area electrical detection, magnetic field disturbances, interlayer potential modulation, and the material's own magnetic coupling simultaneously affect the electrical response signal. This causes the response characteristics generated by different physical mechanisms to superimpose, making the interlayer exchange coupling related signals susceptible to interference from non-target responses, thus failing to accurately reflect the interlayer magnetic interaction state in local regions. Existing measurement methods typically estimate parameters by expanding the scanning range or combining model fitting, but they fail to effectively distinguish the response contributions under different perturbation conditions. Especially in two-dimensional materials with local defects, strain variations, or inhomogeneous interlayer states, this easily leads to insufficient stability in the identification of micro-area interlayer exchange parameters, making it difficult to meet the needs of refined magnetic property analysis.

[0030] To address the aforementioned issues, this study discovered a cross-response characteristic related to interlayer exchange coupling between the magnetic field perturbation response and the interlayer differential potential modulation response. By encoding and combining different perturbation directions, the exchange-related response can be distinguished from individual magnetic field and potential responses. Furthermore, it was found that using orthogonal encoding of magnetic field perturbation directions, interlayer differential potential directions, and cross-combined encoding can establish a correspondence between perturbation conditions and electrical responses, thereby reducing response confusion caused by the superposition of multiple physical factors. Further, by incorporating cross-response data into a two-layer magnetic moment model and combining it with discriminability feedback to adjust perturbation conditions, an adaptive measurement process for micro-region interlayer exchange coupling parameter data is formed.

[0031] After introducing the basic concept of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0032] Example 1:

[0033] like Figure 1 and Figure 2 As shown, a method for measuring the electrical properties of a two-dimensional magnetic material interlayer exchange-coupled micro-region is presented. This method is executed by a measurement system, which also includes a displacement stage, a magnetic field generator, a grid voltage control unit, a lock-in amplifier, and a multi-channel analog-to-digital converter.

[0034] During measurement, the spatial coordinates of the target micro-region are first read from the displacement stage, which is obtained from feedback by the stage's grating ruler. Simultaneously, the current measurement status data is read from the system configuration register, including the center grid voltage, initial value of the magnetic field disturbance amplitude, initial value of the interlayer differential potential disturbance amplitude, and source-drain bias voltage. The system generates two sets of orthogonal encoding sequences based on a preset number of encoding bits: one for the magnetic field disturbance direction and the other for the interlayer differential potential direction. Both sets have the same number of bits, and each bit takes a value of +1 or -1. The system compares the values ​​of the two sets of encoding sequences bit by bit at the same encoding bit. If they are in the same direction, the cross-combination encoding value of that bit is set to +1; otherwise, it is set to -1. This process is repeated for all encoding bits to generate the cross-combination encoding sequence. During the encoding process, the system calculates the Pearson correlation coefficient between each pair of encoded sequences. When the absolute value of any correlation coefficient exceeds a preset correlation threshold, the system adjusts the order of the corresponding coding bits in the encoded sequence or flips their values ​​until the absolute values ​​of the correlation coefficients between any two of the three types of encoded sequences do not exceed the preset correlation threshold. At this point, the three types of encoded sequences satisfy an orthogonal combination relationship. The system arranges each set of intervention encoded data in chronological order. Each set of intervention encoded data contains a complete encoded vector containing the direction of magnetic field disturbance, the direction of interlayer differential potential, and the cross-combination relationship between the two within one encoding period.

[0035] When executing each set of intervention coding data, the system outputs the intervention coding data group by group according to the time sequence. For each set of intervention coding data, the system controls the output current direction of the magnetic field generator according to the value of the coding bit of the magnetic field disturbance direction. The positive and negative directions of the current correspond to the positive and negative magnetic field disturbances, respectively, and the amplitude of the output current is determined by the amplitude of the magnetic field disturbance.

[0036] Simultaneously, the system controls the output of the gate voltage control unit based on the value of the interlayer differential potential direction encoding bit. The gate voltage control unit outputs a first voltage to the upper layer electrode. Output a second voltage to the lower electrode. . and The generation satisfies the following relationship:

[0037] ;

[0038] ;

[0039] in, The center grid voltage data is read from the current measurement status data. This represents the amplitude of the inter-layer differential potential disturbance, and its value is determined by the inter-layer differential potential disturbance amplitude field in the system configuration register. The preset asymmetric allocation coefficient is determined by calibrating the ratio of the effective capacitance coupling coefficients of the upper and lower gates during the initialization phase of the measurement system.

[0040] ;

[0041] Among them, effective capacitance , It is a geometric parallel plate capacitor (determined by the electrode area and the thickness of the insulating layer). The quantum capacitance of a two-dimensional magnetic material (determined by the density of states near the Fermi surface, measured by capacitance-voltage curves). The two layers of magnetic material each... This may vary depending on layer thickness and carrier concentration. The weighted average value of the upper and lower gate voltages is determined by setting this allocation coefficient α. As close as possible to the center gate voltage This reduces the background modulation amplitude of the differential potential disturbance on the total carrier density of the channel, and reduces the interference of non-target resistance drift on the cross-response measurement. When the effective capacitance of the bilayer material is symmetrical ( ), α=0.5, the voltages at the two electrodes are symmetrically distributed about the center gate voltage. Effective capacitance. The calibration method is as follows: During the initialization phase of the measurement system, measure the capacitance-voltage (CV) curves under the individual action of the upper and lower gates, and extract the capacitance value per unit area. Recalibration is required after changing the sample, electrodes, or insulating layer.

[0042] The system performs projection decomposition on the coded response matrix data using three types of coded sequences as a basis. Specifically, it calculates the inner product of each row vector of the coded response matrix data with the coded vector of the magnetic field disturbance direction, the inner product with the coded vector of the interlayer differential potential direction, and the inner product with the cross-combined coded vector. The three types of inner product values ​​are used as the magnetic field individual response data, the interlayer differential potential individual response data, and the preliminary cross-response data under the corresponding measurement conditions, respectively.

[0043] To further separate the interlayer exchange coupling contribution from the preliminary cross-response data, the system utilizes the sign symmetry of magnetic field and potential disturbances to perform the following four-terminal combination operation:

[0044] ;

[0045] in, Indicates positive / reverse magnetic field disturbance. Indicates forward / reverse potential disturbance. This represents the initial cross-response value under the corresponding perturbation direction combination. This combined operation utilizes the symmetry (odd-odd symmetry) of the interlayer exchange coupling response, where both the magnetic field and potential are odd functions, to cancel out non-target contributions such as anisotropic magnetoresistance and interfacial thermoelectric potential. The resulting interlayer exchange coupling separation response data is obtained after this combined operation. Input the two-layer magnetic moment model.

[0046] The system inputs the interlayer exchange-related cross-response data and the center gate voltage and source-drain bias voltage values ​​from the current measurement state data into the pre-stored double-layer magnetic moment model. Before inputting the data into the double-layer magnetic moment model, the system also obtains the material magnetic parameter data corresponding to the target micro-region. The material magnetic parameter data is obtained by one of the following methods: (1) Before performing macroscopic magnetic measurements (such as vibration sample magnetometer VSM or superconducting quantum interference device SQUID measurement) on a standard sample of the same material under the same measurement conditions and storing it in the system configuration register; (2) Pre-setting a typical parameter lookup table (LUT) for different two-dimensional magnetic material types in the measurement system and automatically reading the corresponding default parameter values ​​according to the material type input by the user. The material magnetic parameter data, interlayer exchange-related cross-response data, and current measurement state data are input into the double-layer magnetic moment model together as fixed parameters for model solution or constraint boundaries for the initial search range.

[0047] The model includes interlayer exchange coupling parameter data and magnetic anisotropy parameters as variables to be fitted. A nonlinear least squares algorithm is used to iteratively optimize the model parameters to minimize the sum of squared residuals between the model output and the measured interlayer exchange-related cross-response data. The optimized and converged interlayer exchange coupling parameter data is used as the interlayer exchange coupling parameter data output. At the same time, the covariance matrix of the parameter estimation is calculated based on the Jacobian matrix near the optimal parameters of the model. The square root of the diagonal elements of the covariance matrix is ​​used as the identifiability data.

[0048] Before performing parameter fitting for the two-layer magnetic moment model, the system first transfers the interlayer exchange correlation cross-response data collected from each electrical measurement channel. The measured electrical signal is converted into a normalized response value with dimensions consistent with the model output. Specifically, for the j-th measurement channel, the system converts the measured electrical signal into the equivalent response value corresponding to the model input according to the following formula:

[0049] ;

[0050] in, Let J be the electromagnetic conversion coefficient of the j-th channel: During the initialization phase of the measurement system, the baseline response of each channel is acquired under zero magnetic field conditions as... Under a known saturation magnetization field, the saturation response value is collected, and the saturation response value is compared with the preset saturation magnetization intensity. The ratio as The initial value. For the measurement mode dominated by the tunneling magnetoresistance effect, the initial value is adopted. A linear mapping relationship with the difference in magnetization. The difference in resistance between parallel and antiparallel states. This represents the parallel-state resistance value; for the measurement mode dominated by the anomalous Hall effect, the anomalous Hall resistance of the j-th channel is used. out-of-plane magnetization linear relationship between ,in Let be the anomalous Hall coefficient of the j-th channel.

[0051] The system compares the identifiability data with a preset identification threshold. If the identifiability data does not reach the preset identification threshold, the system further determines the numerical range of the response amplitude of the interlayer exchange-related cross-response data: when the response amplitude is lower than the first amplitude threshold... When the system increases the amplitude of the magnetic field disturbance while keeping other parameters constant; when the response amplitude exceeds the second amplitude threshold... When the interlayer differential potential perturbation amplitude is increased while keeping other parameters constant; when the response amplitude is at the first amplitude threshold... With the second amplitude threshold During this period, the center grid voltage value in the current measurement status data is updated. The system then re-executes the generation of intervention coding data and subsequent steps based on the updated parameters. If the identifiability data reaches the preset identification threshold, the system outputs the currently optimized inter-layer exchange coupling parameter data through the data bus.

[0052] It should be noted that during the projection decomposition process, for Dimensional matrix (G is the number of intervention coding data sets, and C is the number of electrical measurement channels). and All are column vectors of length G, therefore and These are all response vectors of length C, with each element corresponding to the response amplitude of an electrical measurement channel under different magnetic field conditions. Before inputting the two-layer magnetic moment model, the system uses the actual magnetic field values ​​corresponding to each group of intervention coding data. ( ),Will The elements in the equation are rearranged into a function with magnetic field B as the independent variable. That is, to construct the magnetic field-response curve so that the theoretical response output by the model is accurate. Compared with actual measurement Point-by-point comparisons can be performed under the same magnetic field coordinates.

[0053] By employing orthogonal coding excitation and projection decomposition, this application separates the contributions of magnetic field disturbances and inter-layer differential potential disturbances to the electrical response in the time domain. Filtering out non-target coupling effects, it extracts the intrinsic response signal reflecting inter-layer exchange coupling, thereby improving the measurement signal-to-noise ratio and parameter identification accuracy. Simultaneously, through adaptive parameter adjustment based on discriminability feedback, the excitation conditions can be automatically optimized under different measurement conditions, shortening the parameter convergence time.

[0054] This application further proposes that the system generates a magnetic field perturbation direction coding sequence and an interlayer differential potential direction coding sequence according to a preset coding bit length N. N is an even number, set by the system configuration parameters, and its value can be 8, 16, 32, or 64, preferably 16. Each bit in each coding sequence takes +1 or -1, representing the application of a positive or negative perturbation, respectively. When the system generates the coding sequence, the number of bits with a value of +1 in a single coding period of each sequence is equal to the number of bits with a value of -1, both being N / 2. The methods to achieve this balance characteristic include: using a pseudo-random sequence generation algorithm to generate candidate sequences and then screening the balance sequence, selecting any row other than a full row from the Walsh-Hadamard matrix, or performing a balance truncation on the m-sequence.

[0055] After generating two sets of balanced coded sequences, the system compares the values ​​of the two sequences bit by bit at the same coded bit. If the values ​​of the two sets are the same (both +1 or both -1), the cross-combined code is incremented by 1 at that bit; otherwise, it is decremented by 1. After traversing N coded bits, a complete cross-combined coded sequence is formed.

[0056] The system calculates the pairwise correlation data between the three types of coded sequences using the following formula:

[0057] ;

[0058] in, This represents the value at the k-th bit of the i-th type of encoded sequence. This represents the value at the k-th bit of the j-th type of encoded sequence. And i≠j, Let be the correlation coefficient between the coded sequences of class i and class j.

[0059] A preset correlation threshold is stored in the system configuration register, with a value ranging from 0.05 to 0.15, preferably 0.1. This threshold is determined through a calibration process during system initialization: encoding generation and projection decomposition tests are repeatedly performed with different thresholds, and the smallest threshold that ensures a crosstalk suppression ratio of no less than 40dB is selected as the preset correlation threshold. When the absolute value of any correlation coefficient exceeds the preset correlation threshold, it is determined that the corresponding two types of encoded sequences do not meet the orthogonality condition.

[0060] The system performs adjustment operations on encoded sequences that do not meet the orthogonality condition. The adjustment operations include two modes: flip adjustment, which selects encoded bits exceeding a threshold and flips their values ​​from +1 to -1 or from -1 to +1. Simultaneously, a encoded bit in the same sequence with the same original and flipped value is randomly selected and flipped in the opposite direction to maintain the same number of +1s and -1s in the sequence; and sequence rearrangement, which rearranges the order of encoded bits exceeding the threshold while maintaining the same total number of +1s and -1s in each sequence. Preferably, the system prioritizes flip adjustment. If the orthogonality condition is still not met after performing a preset maximum number of flips (e.g., 10 times), the system switches to sequence rearrangement mode.

[0061] After each adjustment operation, the system recalculates the correlation coefficients between each pair of the three types of coding sequences and compares them with a preset correlation threshold. If the absolute value of the correlation coefficient still exceeds the threshold, the adjustment and recalculation continue iteratively until the absolute value of the correlation coefficients between each pair of the three types of coding sequences does not exceed the preset correlation threshold. If the condition is not met even after the number of iterations exceeds the preset maximum number of iterations (e.g., 20), the system regenerates two sets of basic coding sequences and starts the above process from scratch. Preferably, to further ensure that the coding generation is completed within deterministic time, when the number of iterations reaches half of the preset maximum number of iterations (i.e., 10), the system switches to a lookup table method, selecting coding sequences that meet the orthogonality condition from the Walsh-Hadamard matrix pre-stored in non-volatile memory as initial candidate sequences for magnetic field perturbation direction coding and interlayer differential potential direction coding. The order of this Walsh-Hadamard matrix is... The smallest power of 2 that is not less than the preset encoding bit length N (i.e. From this matrix, any two rows (not a complete row) are selected, and the first N bits are truncated and their balance is verified to serve as the basis for the two sets of basic codes. It should be noted that the correlation calculation and flip adjustment are only performed on the two sets of basic codes: the magnetic field disturbance direction code and the interlayer differential potential direction code. The cross-combination code does not participate in independent flip adjustment or sequence rearrangement.

[0062] Once the three types of coding sequences satisfy the orthogonality condition, the system stores the current magnetic field disturbance direction coding sequence, interlayer differential potential direction coding sequence, and cross-combination coding sequence as coding reference data in the coding buffer area, which can be used as the reference vector for projection basis during subsequent projection decomposition.

[0063] Through the above-mentioned balanced coding and orthogonalization iterative processing, the crosstalk between the three types of coding sequences is effectively suppressed, and the separation purity of the contributions of each physical effect during projection decomposition is improved, thereby improving the extraction accuracy of interlayer exchange-related cross-response data and the reliability of subsequent parameter identification.

[0064] Furthermore, before executing the intervention coding data for each group, the system first reads the current measurement status data from the system configuration register. The current measurement status data includes the center grid voltage value, the initial value of the magnetic field disturbance amplitude, the initial value of the interlayer differential potential disturbance amplitude, and the source-drain bias voltage value. Based on the above data, the system outputs current setting signals to the magnetic field generator to generate a static bias magnetic field of corresponding amplitude; outputs voltage setting signals to the gate voltage control unit to apply initial voltages symmetrical about the center gate voltage to the upper and lower electrodes respectively; and outputs setting signals to the source-drain bias source to apply initial source-drain bias voltages within the two-dimensional magnetic material surface. After the outputs of the above actuators stabilize, the system enters the initial reference state corresponding to the current measurement state data.

[0065] After entering the initial reference state, the lock-in amplifier continuously acquires micro-area electrical response data from multiple electrical measurement channels within a preset sampling time window. The duration of the preset sampling time window is set by system configuration parameters, ranging from 100 milliseconds to 5 seconds, preferably 1 second. The system calculates the change in response data of each channel within the preset sampling time window using the following formula:

[0066] ;

[0067] in, This represents the micro-area electrical response data of a certain channel collected at time t within a preset sampling time window. This represents the change in that channel within the sampling time window. The system calculates this for each channel separately. and each channel The maximum value is compared with a preset stability threshold. The preset stability threshold is determined in advance as follows: During the initialization phase of the measurement system, multiple sets of response data are continuously collected when the system is in a known stable state. The fluctuation range of the response data of each channel is statistically analyzed, and 1.2 to 1.5 times the upper limit of the fluctuation range is taken as the preset stability threshold. Specifically, a preset stability threshold is set. The value range is from 0.5% to 2% of the full-scale amplitude of each channel, preferably 1%. If each channel... The maximum value in the range did not exceed the preset stability threshold. This indicates that the system is stable, and the system outputs a signal to allow execution, initiating the execution of each group of intervention code data according to the time sequence. If each channel... The maximum value in exceeds the preset stability threshold. This indicates that the system is still unstable. The system maintains the current output state of the magnetic field generator and the layer selective electrode unchanged, and continues to collect and calculate the change in micro-area electrical response data in the same way. The above comparison process is repeated until the change data does not exceed the preset stability threshold before the intervention coding data is executed.

[0068] Before performing drift correction, at the end of each encoding cycle, the system forces the output current of the magnetic field generator to zero and restores the upper and lower electrode voltages to the initial center grid voltage reference state (i.e., zero-differential perturbation state) before the start of that cycle. During the execution of each set of intervention-encoded data, the lock-in amplifier performs response data acquisition once before the start and once after the end of that encoding cycle to obtain the response data before the start. and response data after completion For each micro-area electrical response data collected under each intervention state within this coding period. The system generates the corrected response data according to the following formula. :

[0069] ;

[0070] in, The total duration of the encoding cycle. This is the time interval between the current response data acquisition time and the start time of the encoding period. The system will then process the corrected response data. Write the response data into the position corresponding to the current intervention state in the encoded response matrix data, replacing the original collected response data, for use in subsequent projection decomposition.

[0071] This application avoids invalid data acquisition during the unsteady-state period of the system by judging the stability under the initial reference state, reduces measurement errors caused by factors such as changes in ambient temperature and electrode contact potential drift, and improves the accuracy and reliability of measurement results.

[0072] This application further proposes that, in each intervention state, the lock-in amplifier applies two sets of source-drain biases in opposite directions sequentially according to the timing control signal output by the system. Specifically, the system outputs a first set value to the source-drain bias source through a digital-to-analog converter channel, causing the source-drain bias source to apply an amplitude of [value missing] along a first direction within the two-dimensional magnetic material surface. The bias voltage; the lock-in amplifier synchronously acquires the response data of multiple electrical measurement channels under this bias direction to obtain the first response data. After data acquisition is complete, the system outputs a second set value to the source-drain bias source, causing the source-drain bias source to apply an amplitude of [value missing] in opposite directions. The bias voltage; the lock-in amplifier synchronously acquires the response data of each channel under this reverse bias to obtain the second response data. The time interval between two data acquisitions is set by system configuration parameters, with a value ranging from 1 millisecond to 100 milliseconds, preferably 10 milliseconds, to ensure that the two data acquisitions are performed under the same system conditions.

[0073] Obtain paired response data and Then, the system performs sum and difference decomposition according to the following formula:

[0074] ;

[0075] in, This is the bias couple response data. This is the bias odd response data. Bias even response data reflects response components independent of the source-drain bias direction. These components originate from non-intrinsic factors such as contact asymmetry between the probe and the material, and differences in the electrode interface barrier, as well as intrinsic effects such as the anisotropic magnetoresistive dipole components and thermoelectric potential of the material. The system distinguishes the sources through harmonic analysis using a lock-in amplifier: when the first harmonic (1f) component exceeds the limit, it is attributed to contact asymmetry and triggers re-contact; when the second harmonic (2f) component exceeds the limit, it is attributed to intrinsic effects and does not trigger re-contact; the bias odd response data reflects response components related to the source-drain bias direction, which contain intrinsic electrical transport information of the material.

[0076] The system compares the bias couple response data of each channel with a preset contact asymmetry threshold. A comparison was made. The preset contact asymmetry threshold was pre-calibrated as follows: During the measurement system initialization phase, the system drove the probe to contact the calibration sample with standard pressure, continuously collected multiple sets of bias couple response data, statistically analyzed their amplitude distribution, and used the mean of the distribution plus three times the standard deviation as the preset contact asymmetry threshold. Specifically, the threshold value ranges from 0.5% to 5% of the full-scale amplitude of each channel, preferably 2%. During comparison, if the absolute value of the bias couple response data of any electrical measurement channel exceeds the preset contact asymmetry threshold... The system determines that there is an asymmetric defect in the electrical contact between the probe and the target micro-region. This defect will cause the intrinsic response signal to be contaminated by false signals introduced by the contact asymmetry.

[0077] After determining that the contact is asymmetric, the system deletes the paired response data of the intervention state from the buffer and does not write it into the encoded response matrix data. Simultaneously, the system outputs a probe re-contact command through the displacement stage drive interface. This command includes the spatial coordinates of the current micro-region and control parameters for the probe's vertical lifting and lowering. Specifically, the re-contact command controls the probe to lift vertically a predetermined distance (ranging from 1 micrometer to 10 micrometers, preferably 5 micrometers), with no horizontal displacement, and then lowers at a predetermined speed (ranging from 1 micrometer / second to 10 micrometers / second, preferably 5 micrometers / second) to re-contact the target micro-region. The system receives the contact force signal from the probe pressure sensor; when the contact force reaches a preset target value... When the value ranges from 0.1 μN to 10 μN, preferably 1 μN, the probe re-contact is confirmed to be complete, and a re-contact completion signal is generated. The current coordinates fed back by the displacement stage grating ruler are compared with the target coordinates, and fine-tuning is performed if the deviation exceeds the limit. After receiving this signal, the system re-executes the intervention coding data corresponding to the current intervention state, that is, re-applies the corresponding magnetic field state and interlayer differential potential state, and re-acquires paired electrical response data, and performs the above sum-difference decomposition and threshold comparison process again.

[0078] If the absolute value of the bias couple response data for each channel does not exceed the preset contact asymmetry threshold, the system determines that the probe contact state is qualified. At this time, the system will output the bias odd response data. Correction is performed by combining the data with drift correction data. Specifically, for the bias odd response data acquired in the m-th acquisition within the current encoding cycle... Correct according to the following formula:

[0079] ;

[0080] in, and These are the bias odd response data obtained by sum-difference decomposition of paired response data collected before and after the start and end of the encoding cycle, respectively. This represents the total duration of the encoding cycle. This represents the time interval between the current data acquisition and the start of the encoding cycle. The system writes the corrected bias odd response data into the encoded response matrix at the position that matches the current intervention state and the corresponding electrical measurement channel, for use in subsequent projection decomposition.

[0081] This application separates the common-mode interference introduced by contact asymmetry from the intrinsic signal by switching the source and drain biases in opposite directions and by sum-difference decomposition. It uses the bias couple response data as a real-time criterion for contact quality and automatically triggers re-contact when the probe has poor contact. This effectively eliminates the measurement spurious signal introduced by changes in the probe contact state, thereby improving the authenticity and reliability of the micro-area electrical response data.

[0082] Furthermore, the system reads the encoding reference data from the encoding buffer, which contains the encoded sequence of magnetic field perturbation directions that satisfies the orthogonal combination relationship. Interlayer differential potential direction coding sequence and cross-combination coding sequences Each sequence has a length of N. Simultaneously, the coded response matrix data M is read from the data buffer. The coded response matrix data is a two-dimensional array with the number of rows equal to the number of intervention coded data groups G and the number of columns equal to the number of electrical measurement channels C. The i-th row corresponds to the corrected response data vector acquired under the i-th intervention state, and the j-th column corresponds to the j-th electrical measurement channel. The system extracts the contribution of each physical effect according to the following projection formula:

[0083] ;

[0084] Where N is the predetermined number of bits in the encoded sequence (i.e., the encoding length), and M is the encoded response matrix data. is a data vector of magnetic field response alone, with a length of C. Each element corresponds to the response amplitude of an electrical measurement channel under the action of magnetic field disturbance alone. The cross-response data vector for interlayer exchange is of length C, and each element corresponds to the cross-response amplitude generated by an electrical measurement channel under the combined effects of magnetic field disturbance and interlayer differential potential. The above projection operation utilizes the orthogonality of the three types of encoded sequences to suppress crosstalk between contributions from different physical effects after projection to a level below the preset correlation threshold.

[0085] get and Then, the system calculates the percentage of inter-layer exchange contribution for each electrical measurement channel according to the following formula:

[0086] ;

[0087] in, The contribution percentage data for a single inter-layer exchange in the j-th channel. For the interlayer exchange-related cross-response data of the j-th channel, This represents the individual magnetic field response data for the j-th channel, where ε is a preset first small positive number (within a range of...). to Preferably ), used to avoid computational overflow caused by a denominator of zero.

[0088] The system provides access to each channel. A comprehensive evaluation was conducted, and each channel was selected. The average value is used as the contribution ratio of inter-layer exchange in the current coding cycle. .Will Compared with the preset contribution percentage threshold Compare the results. Preset contribution percentage threshold. By using standard samples with known interlayer exchange coupling strength during the measurement system initialization phase, projection decomposition and parameter identification are performed under different signal-to-noise ratios. The lowest contribution percentage value that ensures the relative error of the identification result does not exceed 5% is recorded, and 1.2 times this value is used as the preset contribution percentage threshold. Specifically, The value ranges from 5% to 30%, with 15% being preferred.

[0089] like The preset contribution percentage threshold was not reached. This indicates that under the current measurement conditions, the interlayer exchange coupling signal is too weak relative to the magnetic field response signal alone, and the signal-to-noise ratio is insufficient to support reliable parameter identification. The system marks the current coding period as an invalid coding period and records the coding period number in the system log. The system generates disturbance amplitude adjustment data for each channel, based on the logic of comparing the values ​​of each channel. and ,like Below If 30% of the channels account for more than 50% of the total channels, it is determined that the interlayer differential potential perturbation amplitude needs to be increased to enhance the excitation efficiency of the cross-response; otherwise, it is determined that the magnetic field perturbation amplitude needs to be increased to improve the overall amplitude level of the response signal. The adjustment step size is set by the system configuration parameters, with a value ranging from 5% to 20% of the current amplitude, preferably 10%. The system writes the perturbation amplitude adjustment data into the encoding parameter register, triggering the regeneration of intervention encoding data and re-execution of the measurement. If Reaching the preset contribution percentage threshold The system determines that the relative strength of the inter-layer exchange coupling signal under the current measurement state meets the parameter identification requirements, and then extracts the inter-layer exchange-related cross-response data through four-terminal combination operations. Data on contribution ratio of interlayer exchange The two-layer magnetic moment model is input via the data bus as input data for model fitting.

[0090] By calculating the contribution ratio and judging the threshold, this application pre-evaluates the identifiability of interlayer exchange coupling signals before inputting data into the physical model, avoiding invalid parameter fitting calculations under conditions where the signal ratio is too low. At the same time, it optimizes the excitation conditions for subsequent measurements through an automated perturbation amplitude adjustment strategy, thereby improving the efficiency of the overall measurement process and the success rate of parameter identification.

[0091] Furthermore, the system first acquires data on the individual magnetic field response as a function of the magnetic field state. During the measurement process, the magnetic field state corresponding to each group of intervention-coded data is composed of a reference bias magnetic field superimposed with magnetic field perturbations, and the magnetic field values ​​corresponding to each group of magnetic field states are recorded in the measurement log. Individual magnetic field response data. Each magnetic field state corresponds one-to-one, forming a change curve with the magnetic field value as the independent variable and the response amplitude as the dependent variable. The system performs Gaussian smoothing filtering on this curve, with the filter window width set to the number of adjacent magnetic field state points. 5% to 15%, and containing at least 5 data points, with a filter standard deviation of 5%. The value is taken as one-sixth to one-third of the window width to suppress high-frequency measurement noise. After smoothing, the system uses the five-point center difference method to perform second-order numerical differentiation on the filtered curve, specifically calculated according to the following formula:

[0092] ;

[0093] in, For the individual magnetic field response data under the i-th magnetic field state, The magnetic field step size between adjacent magnetic field states ranges from 0.1 mtesla to 5 mtesla, preferably 0.5 mtesla. The system iterates through all magnetic field state points, obtains the filtered second-order differential curve, and then detects the zero-crossing points on the curve—that is, the points where the second-order differential value changes from positive to negative or vice versa. The magnetic field value corresponding to the zero-crossing point is used as the magnetic configuration switching field data. The magnetic configuration switching field data reflects the critical magnetic field value at which the magnetization direction of the magnetic layer in a two-dimensional magnetic material is reversed or reoriented. This value serves as a priori constraint input for subsequent model fitting.

[0094] In one specific embodiment, the two-layer magnetic moment model uses the Landau-Lifshitz equation to describe the magnetization vectors of the upper and lower magnetic layers. and The dynamic evolution is expressed by the following equation:

[0095] ;

[0096] Where i=1,2 represent the upper and lower magnetic layers, respectively. It is the gyromagnetic ratio. Here is the Gilbert damping coefficient. This represents the saturation magnetization. Effective field. Includes external magnetic field Interlayer exchange coupling field Anisotropic fields and the equivalent electric field induced by the gate voltage The specific expression is:

[0097] ;

[0098] ;

[0099] Interlayer exchange coupling field Interlayer exchange coupling parameter data The relationship is , ,in and These represent the thicknesses of the upper and lower magnetic layers, respectively. Gate voltage induced field. Amplitude of interlayer differential potential disturbance The relationship between them is determined by the electromagnetic conversion coefficient. Establish, specifically ,in It is a unit direction vector perpendicular to the plane of the two-dimensional magnetic material.

[0100] Under steady-state conditions, the model solves... and The equilibrium orientation in the effective field yields the theoretical response value. For measurement modes dominated by the tunneling magnetoresistance effect, , where θ is and The angle between them and These are the tunneling resistances in parallel and antiparallel states, respectively.

[0101] After obtaining the magnetic configuration switching field data, the system will Interlayer exchange-related cross-response data extracted through four-terminal combination operations Interlayer exchange contribution ratio data and current measurement status data (including center grid voltage value) Source-drain bias voltage values Input a two-layer magnetic moment model. The two-layer magnetic moment model is a physical model built upon the Landau-Lifshitz-Gilbert equations or the energy minimization principle. Its input parameters include interlayer exchange coupling parameter data. Magnetic anisotropy parameters Interlayer vertical anisotropy parameters Magnetization With the addition of an external magnetic field B, the model output is the theoretical response value. The LLG equations are solved numerically using the fourth-order Runge-Kutta method with a time step of 1 fs. The steady-state criterion is... The nonlinear least squares algorithm employs the Levenberg-Marquardt algorithm, with a maximum of 100 iterations and a convergence tolerance. The system employs the Latin hypercube sampling method to generate multiple sets of candidate parameter data within a preset parameter search range. The preset parameter search range is determined by the material type parameters in the current measurement state data. For typical two-dimensional magnetic materials such as CrI3 and CrGeTe3, the interlayer exchange coupling parameter data... The search range is from -5 mEV to 5 mEV, and the magnetic anisotropy parameter is... The search range is 0 to 2 megajoules per cubic meter. Each set of candidate parameter data contains... The specific values ​​of the four parameters generate a total of 50 to 200 sets of candidate parameters, preferably 100 sets.

[0102] For each set of candidate parameter data, the system calls the two-layer magnetic moment model for calculation. Based on the input candidate parameter values, the model sequentially calculates the theoretical response values ​​corresponding to each magnetic field value within a preset magnetic field scanning range, generating model response data. The format of the model's response data is the same as... They are consistent, both being response curves with the magnetic field value as the independent variable, which facilitates subsequent comparison.

[0103] The measured cross-response data represent the small-signal response under a small-signal perturbation of the differential potential. The system converts the LLG model output into a partial derivative response with respect to the interlayer differential potential:

[0104] ;

[0105] After this transformation, the dimensions of the model output are consistent with those of the measured data. In subsequent comparisons, [the data will be used in conjunction with these dimensions]. Replace the original model response data Perform the calculation.

[0106] The system will process the response data of each model. Cross-response data related to measured inter-layer exchange Compare the results and calculate the model residuals using the following formula:

[0107] ;

[0108] in, The model residuals for the k-th group of candidate parameters are... This represents the total number of magnetic field state points. For the i-th magnetic field value, is the standard deviation of the response data under the i-th magnetic field value (calculated by continuously collecting response data 10 times under each magnetic field state). The model residual reflects the degree of deviation between the model prediction and the measured data; the smaller the residual, the closer the candidate parameters are to the true physical parameters.

[0109] For the model response changes caused by the exchange coupling parameter data between different candidate layers, the system will select the candidate parameters from each candidate parameter. Values ​​are selected at preset intervals, and the differences between corresponding model responses are calculated to obtain response change data. The system performs a two-level evaluation of candidate parameters. The first level is validity screening: model residuals. It must be less than the preset residual threshold, and the contribution ratio The contribution percentage must be greater than a preset threshold; failure to meet any condition results in direct invalidation. The second level is the identification confidence assessment, which calculates Fisher information only for candidate parameters that pass the screening.

[0110] ;

[0111] in, Let be the model residual (dimensionless) under the k-th group of candidate parameters. Data on the contribution percentage of inter-layer exchange (dimensionless, ranging from 0 to 1). The system selects... The largest candidate parameter is output. This refers to identifiability data.

[0112] Preset residual threshold Pre-calibration is performed as follows: During the measurement system initialization phase, using simulation data with known true parameters, the model residual distribution under different candidate parameters is calculated, and twice the residual corresponding to the true parameter is used as the preset residual threshold. Specifically, the threshold value ranges from 0.5 to 5, preferably 1.5. The system filters candidate parameter data whose model residuals do not exceed the preset residual threshold, and selects identifiable data from these candidate data. The largest candidate parameter data, including the interlayer exchange coupling parameter data. This serves as the final output of interlayer exchange coupling parameter data.

[0113] By automatically extracting magnetic configuration switching field data through second-order differential processing of individual magnetic field response curves, prior constraints are provided for the two-layer magnetic moment model, reducing the parameter search space. By combining parallel fitting of multiple candidate parameters with a comprehensive evaluation of model residuals and identifiability, overfitted parameter combinations are eliminated, ensuring that the output parameters have clear physical credibility.

[0114] Furthermore, the system first reads the identifiability data I and the model residual data from the status register. The two are compared with preset recognition thresholds respectively. and preset residual threshold Comparison. Preset recognition threshold. Pre-calibration is performed as follows: During system initialization, calibration samples with known interlayer exchange coupling parameter data are used to perform parameter identification under different measurement conditions. The correspondence between identifiability data and relative identification error is statistically analyzed, and the minimum identifiability value corresponding to a relative identification error of no more than 5% is used as the preset identification threshold. . Specifically, The value ranges from 0.1 to 2.0, with 0.5 being the preferred value.

[0115] When the identifiability data fails to reach the preset identification threshold and the model residual data exceeds the preset residual threshold, the system prioritizes the following judgment: If the response amplitude of the current inter-layer exchange-related cross-response data is lower than the preset amplitude lower limit threshold (the preset amplitude lower limit threshold is 1% to 5% of the full-scale amplitude of each channel, preferably 2%), then it is determined that the residual exceeding the standard is due to insufficient signal strength, and at this time, according to... and Under the same conditions, adjust the magnetic field disturbance amplitude or the interlayer differential potential disturbance amplitude in the same way; if the current response amplitude is not lower than the preset lower limit threshold, it is determined that the residual exceeds the standard because the magnetic field scanning range does not cover the magnetic configuration switching area, and the following central magnetic field update operation is performed.

[0116] when and At this point, it indicates that the current model response can describe the measured data well (residuals are acceptable), but the sensitivity of the inter-layer exchange coupling parameter data to the model output is insufficient to support high-confidence identification. At this time, the model response change data caused by different candidate inter-layer exchange coupling parameter data obtained by the system... The system estimates the increase in discernibility after adjusting the magnitude of the magnetic field disturbance and the magnitude of the inter-layer differential potential disturbance, respectively. Specifically, the system predicts the increase in the magnitude of the magnetic field disturbance based on the relationship between the current response amplitude and the disturbance amplitude. The change in the post-model response, combined with the current inter-layer exchange contribution ratio data. The increase in discernibility after adjusting the amplitude of the magnetic field disturbance is calculated using the following formula:

[0117] ;

[0118] in, The conversion coefficient for adjusting the magnetic field disturbance amplitude to the response amplitude is determined by the ratio of the magnetic field disturbance amplitude to the measured response amplitude under the current measurement state. The step size for adjusting the preset magnetic field disturbance amplitude ranges from 5% to 20% of the current amplitude, preferably 10%. Similarly, the system calculates and adjusts the amplitude of the inter-layer differential potential disturbance. Increased recognizability afterward:

[0119] ;

[0120] in, This is the conversion coefficient for adjusting the response amplitude to the interlayer differential potential disturbance amplitude. The preset step size for adjusting the interlayer differential potential disturbance amplitude ranges from 5% to 20% of the current amplitude, preferably 10%. System Comparison and The size of the perturbation amplitude is used to select the type of perturbation amplitude with the largest increase in identifiability as the adjustment target. The adjusted perturbation amplitude value is then written into the encoding parameter register as the perturbation amplitude data for the next encoding cycle. If the identifiability increment of both adjustment methods is lower than the preset increment threshold... (The value ranges from 0.01 to 0.1, preferably 0.05), then the system simultaneously increases the amplitude of both disturbances slightly.

[0121] when and This indicates a significant deviation between the current model response and the measured data. Given that the switching field was confirmed during the coarse scan phase... Within the scanning range, the excessive residuals are likely caused by insufficient scanning window width, resulting in inadequate curve feature information near the switching region. In this case, the system does not move the central magnetic field but instead expands the scanning window: increasing the scanning amplitude of the current fine scan magnetic field. The value is expanded to 1.5 times the original value (with the central magnetic field position unchanged) to cover a wider switching field neighborhood. If the residual still does not meet the target after three consecutive expansions, the system returns to coarse scan mode to reposition the switching field.

[0122] After obtaining the perturbation amplitude data for the next coding cycle or the current measurement status data, the system re-executes the generation of intervention coding data and all subsequent steps according to the updated parameters. The system maintains an update counter to record the number of consecutive updates for the current target micro-region. When the number of consecutive updates reaches the preset maximum update count... (The value ranges from 3 to 10, preferably 5). If the identifiability data still does not reach the preset identification threshold, then... When the system determines that the measurement conditions of the target micro-region cannot meet the parameter identification requirements, it outputs a target micro-region measurement anomaly command. This command includes the spatial coordinates of the current micro-region, the anomaly code, and the identifiability data and model residual data obtained from the last measurement.

[0123] By employing adaptive parameter adjustment driven by discernible feedback, this application adopts two differentiated strategies—disturbance amplitude optimization or central magnetic field adjustment—based on different failure causes. This avoids blind, traversal parameter scanning and effectively shortens the measurement time for a single micro-area. Simultaneously, a protection mechanism for the maximum number of updates prevents the system from entering an infinite loop under unrecoverable abnormal measurement conditions, ensuring the overall execution efficiency of the multi-point scanning measurement process.

[0124] Once the identifiability data reaches a preset identification threshold, the system reads the spatial coordinates of the current target micro-region, inter-layer exchange coupling parameters, and identifiability data. It then associates these three types of data according to a preset data structure to generate target micro-region measurement record data. This record data is stored in a temporary measurement record buffer for subsequent comparison of measurement results from adjacent micro-regions. Based on the spatial coordinates of the current target micro-region, the system superimposes a preset step interval along a preset scanning direction to generate a displacement stage control command pointing to an adjacent micro-region. This command contains the target position's coordinate information and displacement velocity parameters, and is output through the displacement stage drive interface to control the displacement stage to move to the adjacent micro-region.

[0125] After the displacement stage reaches the adjacent micro-region, the system directly writes the current measurement state data used by the current target micro-region when the identifiability meets the standard into the system configuration register to avoid re-establishing measurement conditions. Subsequently, a complete intervention-coded measurement process is performed on the adjacent micro-region to obtain the interlayer exchange coupling parameter data and its identifiability data of the adjacent micro-region, and measurement record data of the adjacent micro-region is generated according to the same data structure.

[0126] After obtaining the measurement records of adjacent micro-regions, the system compares the measurement records of the target micro-region with those of the adjacent micro-regions. The specific comparison logic is as follows: when the difference in interlayer exchange coupling parameter data between two micro-regions exceeds a preset spatial difference threshold... The difference in the cross-response data between the two micro-regions did not exceed the preset response difference threshold. This indicates a discrepancy between the parameter jump and the original response signal jump. This discrepancy is usually caused by transient interference or occasional measurement errors introduced by contact state fluctuations during the measurement process. The system generates a repeatable measurement command pointing to the target micro-region and the adjacent micro-region. This command contains the coordinate data of the two micro-regions. The system controls the displacement stage to return to the two micro-regions sequentially and re-execute the complete measurement process. A preset spatial difference threshold is set. Pick 10% of the change, preset response difference threshold Pick The 15% variation was determined through statistical analysis of calibrated samples.

[0127] If the above conditions are not met, i.e., the parameter differences and response differences between the two micro-regions are consistent, the system determines that both measurements are valid and fuses the interlayer exchange coupling parameter data from the target micro-region measurement record data with the interlayer exchange coupling parameter data from the adjacent micro-region measurement record data. The fusion method is a weighted average based on the respective identifiability data, with the weights determined by normalizing the identifiability data values. The system combines the fused interlayer exchange coupling parameter data, the coordinate data of the two micro-regions, and the corresponding identifiability data into a single interlayer exchange coupling micro-region quantization mapping data record, and writes it to the interlayer exchange coupling micro-region quantization mapping database pre-stored in non-volatile memory to update the interlayer exchange coupling micro-region quantization mapping data.

[0128] This application effectively identifies occasional abnormal data during the measurement process by cross-comparison and contradiction detection of measurement data from adjacent micro-regions, thus avoiding the contamination of the quantization mapping database by erroneous data. Through data fusion with identifiability weighting, it improves data accuracy when the measurement results of adjacent micro-regions are consistent. It realizes spatial correlation storage of measurement results and automatic database updates, providing a data foundation for subsequent spatial distribution analysis of magnetic parameters in micro-regions of two-dimensional magnetic materials.

[0129] The following is a specific embodiment of a two-dimensional magnetic material interlayer exchange-coupled micro-region electrical measurement method:

[0130] This embodiment uses the measurement of interlayer exchange coupling in the micro-region of a single-crystal sample of two-dimensional magnetic material CrI3 as an example. A CrI3 sheet (approximately 5 nm thick, approximately 20 μm in lateral dimension) prepared by mechanical exfoliation was transferred onto a multi-gate device chip covered with a SiO2 (300 nm) / Si substrate. Upper and lower Cr / Au electrodes (5 nm / 50 nm thick) were fabricated using electron beam lithography to form a dual-gate field-effect transistor structure. The entire device was mounted in a low-temperature probe station (temperature stabilized at 1.8 K), with the probe station positioned at the center of the electromagnet's pole gap, and the magnetic field direction perpendicular to the sample plane.

[0131] Before the measurement begins, the system reads the current measurement status parameters from the configuration register: center grid voltage value. Source-drain bias voltage Initial value of magnetic field disturbance amplitude Initial value of interlayer differential potential disturbance amplitude The preset encoding bit length N=16, and the preset correlation threshold is 0.1. The system generates a 16-bit magnetic field perturbation direction encoding sequence according to the equilibrium condition, for example... (8 +1s and 8 -1s), simultaneously generating interlayer differential potential direction encoding sequences that satisfy the same equilibrium condition. The cross-combined coding sequence is obtained by comparing the values ​​of the two sets of coding sequences bit by bit. Calculate the correlation coefficients between each pair of the three types of coded sequences to obtain... If the correlation exceeds the preset correlation threshold of 0.1, a polarity reversal operation is triggered: the polarity of the 3rd and 11th bits is reversed (+1 is reversed to -1, and -1 is reversed to +1), and the correlation coefficient is recalculated to reach the target value. The three types of encoding satisfy an orthogonal combination relationship.

[0132] The system outputs intervention-coded data in groups according to the time sequence. For each group of intervention-coded data, the magnetic field generator outputs a positive or reverse current based on the value of the magnetic field disturbance direction encoding bit, generating a magnetic field disturbance increment of ±5mT. Simultaneously, the gate voltage control unit outputs a first voltage to the upper electrode based on the value of the interlayer differential potential direction encoding bit. The lower electrode outputs a second voltage. .in Therefore The upper and lower gate voltages are asymmetrical about the center gate voltage, but the weighted average remains at 0.5V.

[0133] The lock-in amplifier synchronously acquires response data from four electrical measurement channels in each intervention state. After drift correction and probe contact judgment, the data is arranged in rows to form a 16-row × 8-column coded response matrix. The system performs projection decomposition on the coded response matrix using three types of coded sequences as a basis to obtain individual magnetic field response data. Interlayer exchange of relevant cross-response data .calculate and The ratio of the response amplitudes was used as the contribution ratio of inter-layer exchange, which was obtained in this measurement. If the contribution percentage exceeds a preset threshold of 15%, the signal strength is determined to meet the parameter identification requirements. The system will then exchange relevant cross-response data between layers. The current measurement state is used to input a two-layer magnetic moment model, which employs the Landau-Lifshitz-Gilbert equations to describe the dynamic evolution of the magnetization vectors of the upper and lower magnetic layers. Latin hypercube sampling is used to generate 100 candidate parameter combinations, each containing interlayer exchange coupling parameters. Magnetic anisotropy parameters Interlayer vertical anisotropy parameters and saturation magnetization Calculate the model response for each set of candidate parameters and compare it with the measured response. The model residuals were obtained. Generate identifiable data. Candidate parameter combinations with model residuals less than a preset residual threshold of 1.5 are selected, and finally, the most identifiable combinations are chosen. The largest candidate parameter is used as the output result to obtain the interlayer exchange coupling parameter data for this micro-region. millielectronvolts, corresponding discernibility The preset recognition threshold of 0.5 has been reached.

[0134] After the measurement is completed, the system associates the spatial coordinates of the current micro-region, the interlayer exchange coupling parameter data, and the identifiability data to form a measurement record, which is then written into the interlayer exchange coupling micro-region quantization mapping database. The system then steps 200 nm along the X-direction to the adjacent micro-region according to the preset scan path, using the current central gate voltage value and perturbation amplitude parameters as initial state data to begin the measurement of the next micro-region.

[0135] This embodiment realizes non-destructive in-situ measurement of interlayer exchange coupling parameters in micro-regions of two-dimensional magnetic materials, providing basic data for subsequent spatial distribution imaging and evaluation of interlayer coupling uniformity.

[0136] Example 2:

[0137] like Figure 3 and Figure 4As shown, the two-dimensional magnetic material interlayer exchange-coupled micro-area electrical measurement system uses the above-mentioned two-dimensional magnetic material interlayer exchange-coupled micro-area electrical measurement method, including a measurement and encoding generation module 100, an excitation and response acquisition module 200, a cross-response extraction module 300, a parameter identification module 400, and a feedback and displacement control module 500.

[0138] The measurement and encoding generation module 100 includes a system (selected from embedded processors, FPGAs, or DSPs), an encoding buffer (selected from SRAM memory), and a configuration register. The system reads the spatial coordinate data of the target micro-area from the displacement stage grating ruler via the displacement stage interface and reads the current measurement status data from the system configuration register. The system integrates encoding generation logic circuitry, which generates a magnetic field disturbance direction encoding sequence and an interlayer differential potential direction encoding sequence according to a preset encoding bit length N. It compares the values ​​of the two sets of sequences bit by bit to generate a cross-combination encoding sequence, and uses correlation calculation and iterative adjustment to ensure that the three types of encoding sequences satisfy an orthogonal combination relationship. The measurement and encoding generation module 100 stores the generated intervention encoding data in chronological order into the encoding buffer, and simultaneously outputs it to the excitation and response acquisition module 200 and the cross-response extraction module 300 via the data bus.

[0139] The excitation and response acquisition module 200 includes a magnetic field generator (using an electromagnet or Helmholtz coil), a grid voltage control unit (including a dual-channel digital-to-analog converter, each channel having a resolution of at least 16 bits), a source-drain bias source (including a programmable voltage source), a lock-in amplifier (including a multi-channel analog-to-digital converter, with a sampling rate of at least 100 kHz), and a displacement stage controller. The excitation and response acquisition module 200 reads each set of intervention-encoded data from the encoding buffer in a time sequence. For each set of intervention-encoded data, the magnetic field generator changes the direction of its output current according to the value of the encoding bit for the magnetic field disturbance direction, generating positive and negative magnetic field disturbances; the grid voltage control unit outputs a first voltage and a second voltage, symmetrical about the central grid voltage, to the upper and lower electrodes respectively, based on the value of the encoding bit for the interlayer differential potential direction; the source-drain bias source applies source-drain biases in opposite directions sequentially in each intervention state. The lock-in amplifier synchronously acquires micro-area electrical response data from multiple electrical measurement channels. The analog signals of each channel are converted into digital signals after analog-to-digital conversion. After being aligned with the coded bit values ​​of the current intervention coded data in time, they are arranged in rows to form a coded response matrix and stored in the data buffer.

[0140] The cross-response extraction module 300 includes a computing unit and a data buffer (selected as SRAM or DRAM). The cross-response extraction module 300 reads encoded reference data from the encoding buffer and encoded response matrix data from the data buffer. Using the magnetic field perturbation direction encoding sequence, the interlayer differential potential direction encoding sequence, and the cross-combination encoding sequence as a basis, it performs projection decomposition on the encoded response matrix data to obtain individual magnetic field response data, individual interlayer differential potential response data, and interlayer exchange-related cross-response data. The interlayer exchange-related cross-response data is then stored in the parameter buffer.

[0141] The parameter identification module 400 includes a non-volatile memory (containing the two-layer magnetic moment model program code, preferably flash memory) and a parameter buffer. The parameter identification module 400 reads interlayer exchange-related cross-response data from the parameter buffer and reads the current measurement state data from the system configuration register, inputting this data into the two-layer magnetic moment model stored in the non-volatile memory. The system executes the model program, uses a nonlinear least squares algorithm to fit the parameters, generates interlayer exchange-coupling parameter data and its identifiability data, and writes the identifiability data into the state register.

[0142] The feedback and displacement control module 500 includes a status register, an encoding parameter register, and a displacement stage controller. The feedback and displacement control module 500 reads the identifiability data from the status register and compares it with a preset identification threshold. If the preset identification threshold is not reached, the feedback and displacement control module 500 further reads the response amplitude of the inter-layer exchange-related cross-response data, determines the numerical range of the response amplitude, generates a corresponding parameter adjustment command based on the range determination result, and writes the adjusted parameters into the encoding parameter register, triggering the measurement and encoding generation module 100 to regenerate the intervention encoding data. If the preset identification threshold is reached, the feedback and displacement control module 500 outputs the current inter-layer exchange coupling parameter data through the data bus, calculates the target position of the adjacent micro-area based on the spatial position coordinate data, and drives the displacement stage to move to the next target micro-area through the displacement stage controller.

[0143] In one specific embodiment, the above system is used to perform micro-region interlayer exchange coupling measurements on a two-dimensional magnetic material CrGeTe3 sample. The measurement and encoding generation module 100 generates a 32-bit orthogonal encoding sequence (N=32, preset correlation threshold 0.1). A magnetic field generator applies a magnetic field perturbation with an amplitude range of ±20 millitalas according to the encoding sequence. A gate voltage control unit applies an interlayer differential potential perturbation with an amplitude range of ±0.5 volts. A source-drain bias source applies a source-drain bias with an amplitude of 5 millivolts. A lock-in amplifier acquires response data from four electrical measurement channels at a sampling rate of 2 kHz. The measurement temperature is stabilized at 10 K to verify the system's applicability under higher temperature conditions. After orthogonal encoding excitation, projection decomposition, and fitting of the two-layer magnetic moment model parameters, the micro-region interlayer exchange coupling parameter data is output as follows: The nanoelectron volts (mV) have a discriminability of 0.73, reaching the preset discriminability threshold of 0.5. The feedback and displacement control module 500 generates displacement stage control commands, driving the displacement stage to step 300 nanometers along the X direction to the next adjacent micro-region.

[0144] The orderly transfer and collaborative operation of data are achieved through data buffers, registers, and buses between modules, avoiding tight coupling and dependencies between modules and improving the system's parallel processing capabilities. The orthogonal coding sequence generated by the measurement and coding generation module ensures the separation purity of the projection decomposition by the cross-response extraction module. The feedback and displacement control module optimizes the measurement conditions based on the identifiability adaptive adjustment. The identifiability data output by the parameter identification module provides a quantitative basis for the confidence of the measurement results, ensuring the reliability of the interlayer exchange and coupling parameter data.

[0145] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.

Claims

1. A method for measuring the electrical properties of a two-dimensional magnetic material through interlayer exchange coupling in a micro-region, characterized in that: Includes the following steps: The spatial coordinates and current measurement status data of the target micro-region are acquired, and multiple sets of intervention coding data are generated, consisting of magnetic field disturbance direction coding and interlayer differential potential direction coding with a predetermined number of bits. Cross-combination coding is generated according to the same-direction or opposite-direction relationship of various coding bits. The magnetic field disturbance direction coding, the interlayer differential potential direction coding and the cross-combination coding satisfy an orthogonal combination relationship. The magnetic field state of the target micro-region is changed according to the intervention coding data of each group, and an equal-amplitude and opposite-reverse potential perturbation is applied to the adjacent magnetic layer. The electrical response data of the micro-region is collected synchronously, and the electrical response data of the micro-region is associated with the corresponding intervention coding data to generate the coding response matrix data. Based on the magnetic field disturbance direction coding, the interlayer differential potential direction coding, and the cross-combination coding of the two, the coding response matrix data is projected and decomposed to generate interlayer exchange-related cross-response data. The interlayer exchange-related cross-response data and the current measurement state data are input into a preset two-layer magnetic moment model to generate interlayer exchange coupling parameter data and its identifiability data; The identifiability data is compared with a preset identification threshold. If the preset identification threshold is not reached, at least one of the following is selected to update: magnetic field disturbance amplitude, interlayer differential potential disturbance amplitude, or current measurement state data, based on whether the model residual data exceeds the preset residual threshold and the numerical range of the response amplitude of the interlayer exchange-related cross-response data. The intervention coding data is then regenerated and returned for execution. If the preset identification threshold is reached, the interlayer exchange coupling parameter data is output.

2. The method for measuring the electrical properties of a two-dimensional magnetic material through interlayer exchange coupling in a micro-region according to claim 1, characterized in that: The generation of the multiple sets of intervention coding data includes: The magnetic field disturbance direction code and the interlayer differential potential direction code are generated according to the predetermined number of bits, so that the number of bits for the forward code and the number of bits for the reverse code are the same in one coding cycle for each direction code; The cross-combination code is generated based on the same-direction or opposite-direction relationship of the corresponding coding bits. The cross-combination code is the bitwise product of the magnetic field perturbation direction code and the interlayer differential potential direction code. Calculate the correlation data between the magnetic field disturbance direction code and the interlayer differential potential direction code. When the correlation data exceeds a preset correlation threshold, perform a flip adjustment or sequence rearrangement on at least one of the magnetic field disturbance direction code or the interlayer differential potential direction code until the two satisfy the orthogonal combination relationship.

3. The method for interlayer exchange-coupled micro-region electrical measurement of two-dimensional magnetic materials according to claim 1, characterized in that: The magnetic field state of the target micro-region is changed according to the intervention coding data of each group, and an equal-amplitude and opposite-reverse potential perturbation is applied to the adjacent magnetic layer, including: Read the center gate voltage data from the current measurement state data, and generate upper electrode control voltage data and lower electrode control voltage data according to the center gate voltage data and the interlayer differential potential direction code, so that the average value of the two electrode control voltages is maintained as the center gate voltage data, and the difference direction of the two electrode control voltages corresponds to the interlayer differential potential direction code; The upper electrode control voltage data and the lower electrode control voltage data are sent to the corresponding digital-to-analog conversion channels, and the actual voltage feedback data of the two electrodes are collected. When the deviation between the actual voltage feedback data and the corresponding electrode control voltage data exceeds a preset voltage deviation threshold, the disturbance amplitude field in the corresponding intervention coding data is updated using the actual voltage feedback data, so that the disturbance amplitude field participates in the projection decomposition of the coding response matrix data.

4. The method for measuring the electrical properties of two-dimensional magnetic materials through interlayer exchange coupling in a micro-region according to claim 1, characterized in that: Before changing the magnetic field state of the target micro-region according to the intervention coding data of each group, the following is also included: The magnetic field generator and the layer selective electrode are controlled to enter the initial reference state corresponding to the current measurement state data, and the micro-area electrical response data under the initial reference state are collected. Calculate the change in the micro-area electrical response data within a preset sampling time window, compare the change with a preset stability threshold, execute the corresponding intervention coding data when the change does not exceed the preset stability threshold, and maintain the initial reference state and continue to collect the micro-area electrical response data when the change exceeds the preset stability threshold. Drift correction data is generated based on the micro-area electrical response data before and after the start and end of a coding cycle, and the drift correction data is used to correct the micro-area electrical response data of the corresponding coding cycle in the coding response matrix data.

5. The method for measuring the electrical properties of a two-dimensional magnetic material through interlayer exchange coupling in a micro-region according to claim 4, characterized in that: Simultaneous acquisition of multi-channel micro-area electrical response data, including: In each intervention state, source-drain biases with opposite directions are applied, and paired electrical response data corresponding to the two source-drain biases are collected. The pair of electrical response data is decomposed into sum and difference. Bias couple response data is generated based on the average value of the response data corresponding to the source and drain bias in the two directions. Bias odd response data is generated based on the difference between the response data corresponding to the source and drain bias in the two directions. The bias couple response data is compared with a preset contact asymmetry threshold. When the bias couple response data exceeds the preset contact asymmetry threshold, the paired electrical response data in the corresponding intervention state is deleted and a probe re-contact command is output. After receiving the probe re-contact completion signal, the corresponding intervention coding data is re-executed. When the bias couple response data does not exceed the preset contact asymmetry threshold, the bias odd response data is corrected by the drift correction data and written into the coded response matrix data.

6. The method for measuring the electrical properties of a two-dimensional magnetic material through interlayer exchange coupling in a micro-region according to claim 1, characterized in that: Projective decomposition of the encoded response matrix data includes: The encoded response matrix data is projected based on the magnetic field disturbance direction encoding, the interlayer differential potential direction encoding, and the cross-combination encoding to generate individual magnetic field response data and interlayer exchange-related cross-response data. The ratio of the response amplitude of the inter-layer exchange-related cross-response data to the response amplitude of the magnetic field-only response data is calculated as the contribution ratio of inter-layer exchange. The inter-layer exchange contribution ratio data is compared with a preset contribution ratio threshold. If the preset contribution ratio threshold is not reached, the current coding period is marked as an invalid coding period, and perturbation amplitude adjustment data is generated. If the preset contribution ratio threshold is reached, the inter-layer exchange related cross-response data and the inter-layer exchange contribution ratio data are input into the two-layer magnetic moment model.

7. The method for measuring the electrical properties of a two-dimensional magnetic material through interlayer exchange coupling in a micro-region according to claim 6, characterized in that: Generate inter-layer exchange coupling parameter data and its identifiability data, including: The magnetic field response data of the individual magnetic field is processed by second-order differential, and the magnetic field value corresponding to the zero crossing point of the second-order differential value is used as the magnetic configuration switching field data. The magnetic configuration switching field data, the interlayer exchange-related cross-response data, the interlayer exchange contribution ratio data, and the current measurement state data are input into a two-layer magnetic moment model containing interlayer exchange coupling parameter data and magnetic anisotropy parameters to generate multiple sets of candidate parameter data and their corresponding model response data. The model response data is compared with the inter-layer exchange-related cross-response data to generate model residual data. The identifiability data is generated based on the model response change data caused by different candidate inter-layer exchange coupling parameter data, the model residual data, and the inter-layer exchange contribution ratio data. From the candidate parameter data whose model residual data does not exceed the preset residual threshold, the candidate parameter data with the largest identifiability data is selected as the interlayer exchange coupling parameter data.

8. The method for measuring the electrical properties of a two-dimensional magnetic material through interlayer exchange coupling in a micro-region according to claim 7, characterized in that: Select to update at least one of the following: magnetic field disturbance amplitude, interlayer differential potential disturbance amplitude, or the current measurement state data, including: When the identifiability data does not reach the preset identification threshold and the model residual data does not exceed the preset residual threshold, the identifiability increment data after adjusting the magnetic field disturbance amplitude and the interlayer differential potential disturbance amplitude are obtained according to the model response change data, and the disturbance amplitude data of the next encoding cycle is generated according to the identifiability increment data. When the identifiability data does not reach the preset identification threshold and the model residual data exceeds the preset residual threshold, the central magnetic field data in the current measurement state data is updated according to the magnetic configuration switching field data to generate the current measurement state data for the next encoding cycle. The intervention coding data is regenerated using the disturbance amplitude data of the next coding cycle or the current measurement status data; if the identifiability data still does not reach the preset identification threshold after a preset number of consecutive updates, a target micro-area measurement anomaly command is output.

9. The method for measuring the electrical properties of a two-dimensional magnetic material through interlayer exchange coupling in a micro-region according to claim 8, characterized in that: After the identifiability data reaches the preset identification threshold, the method further includes: The spatial coordinate data, interlayer exchange coupling parameter data, and identifiability data of the target micro-region are correlated to generate target micro-region measurement record data, and displacement stage control commands pointing to adjacent micro-regions are generated based on the spatial coordinate data. The current measurement status data of the target micro-region is used as the initial measurement status data of the adjacent micro-region. Intervention coding measurement is performed on the adjacent micro-region to generate adjacent micro-region measurement record data. The target micro-area measurement record data is compared with the adjacent micro-area measurement record data. When the difference in the interlayer exchange coupling parameter data between adjacent micro-areas is inconsistent with the difference in the corresponding interlayer exchange-related cross-response data, a repeat measurement instruction is generated pointing to the target micro-area and the adjacent micro-area; otherwise, the interlayer exchange coupling parameter data in the target micro-area measurement record data and the adjacent micro-area measurement record data are fused and written into a pre-stored interlayer exchange coupling micro-area quantization mapping database.

10. A two-dimensional magnetic material interlayer exchange-coupled micro-region electrical measurement system, characterized in that: The method for measuring the electrical properties of a two-dimensional magnetic material through interlayer exchange coupling in a micro-region, as described in any one of claims 1 to 9, includes: The measurement and coding generation module is used to acquire the spatial location coordinate data and current measurement status data of the target micro-region, generate multiple sets of intervention coding data consisting of magnetic field disturbance direction coding and interlayer differential potential direction coding with a predetermined number of bits, and generate cross-combination coding according to the same or opposite direction relationship of various coding bits; the magnetic field disturbance direction coding, the interlayer differential potential direction coding and the cross-combination coding satisfy an orthogonal combination relationship. The excitation and response acquisition module is used to change the magnetic field state of the target micro-region according to each set of intervention coding data, and apply equal-amplitude and opposite-phase potential perturbations to adjacent magnetic layers, synchronously acquire micro-region electrical response data, associate the micro-region electrical response data with the corresponding intervention coding data, and generate coded response matrix data. The cross-response extraction module is used to perform projection decomposition on the encoded response matrix data based on the magnetic field disturbance direction encoding, the interlayer differential potential direction encoding, and the cross-combination encoding of the two, to generate interlayer exchange-related cross-response data. The parameter identification module is used to input the interlayer exchange-related cross-response data and the current measurement state data into a preset two-layer magnetic moment model to generate interlayer exchange coupling parameter data and its identifiability data. The feedback and displacement control module is used to compare the identifiability data with a preset identification threshold. If the preset identification threshold is not reached, it selects to update at least one of the following based on whether the model residual data exceeds the preset residual threshold and the numerical range of the response amplitude of the interlayer exchange-related cross-response data: the magnetic field disturbance amplitude, the interlayer differential potential disturbance amplitude, or the current measurement state data, and regenerates the intervention coding data and returns it for execution. If the preset identification threshold is reached, it outputs the interlayer exchange coupling parameter data.

Images