Synchronous vector magnetic field measurement device, method and equipment based on diamond NV color center, medium and product

Abstract

The invention discloses a synchronous vector magnetic field measurement device, method and equipment based on a diamond NV color center, a medium and a product, and relates to the field of magnetic field measurement, and the method comprises the steps: constructing a magnetic field Cartesian coordinate system of an NV magnetometer; four microwave modulation signals are generated to apply excitation signals to the diamond at different frequencies, so that information from a plurality of NV directions is encoded in independent frequency bands, and measurement is performed on an optical detector in a diamond NV color center magnetometer probe to obtain voltage signals; performing phase-locked demodulation and filtering to extract signals related to each NV direction to obtain voltage offsets of different NV axes; the voltage offsets of different NV axes are converted into frequency offsets through the zero crossing point slope of the demodulation curve; determining the change relation between the frequency variation of the four NV axes and the three-axis magnetic field component; determining an effective gyromagnetic ratio matrix; calculating a left pseudo-inverse matrix; according to the invention, all Cartesian components of the dynamic magnetic field in the NV color center ensemble can be synchronously measured in real time.

Description

Technical Field

[0001] The present application relates to the field of magnetic field measurement, and in particular to a synchronous vector magnetic field measurement device, method, equipment, medium and product based on diamond NV color center. Background Art

[0002] With the rapid development of quantum technology, diamond nitrogen vacancy (NV)-based magnetometers are widely used in magnetic anomaly detection, current detection, geomagnetic navigation, biomagnetic field detection, and imaging due to their advantages of high sensitivity, high detection range, high stability, and adaptability to different environments at room temperature. Conventional scalar magnetometers such as Overhauser effect magnetometers can only measure the magnitude of the magnetic field. Vector projection magnetometers such as Hall probes can only measure the projection of the magnetic field along a specified axis in the air. If the vector magnitude of the magnetic field needs to be measured, multiple sensors need to be arranged along different axes. The relative direction errors of these sensors affect the accuracy of the vector field. In contrast, the fixed crystal axis inherent in solid-state spin sensors allows for vector field sensing while reducing the system errors caused by sensor axis misalignment and drift gain.

[0003] The detection technology of the traditional NV magnetometer is to obtain the ODMR spectrum by exciting the diamond with a laser and radiating it with microwaves in sequence to obtain the respective resonance peak frequencies, and then calculate the magnetic field component on the NV axis by the frequency deviation on each resonance peak. The disadvantage is that the frequency sweep time is too slow and the change of the magnetic field cannot be monitored in real time. Most of the integrated vector NV magnetometers use the traditional frequency hopping method, which realizes the measurement of the vector by continuously resonating the microwave source on different axes of the NV color center in sequence. This method can only sense static or slowly changing magnetic fields. When the speed of the magnetic field change exceeds the frequency hopping time, the vector solution is inaccurate. Secondly, the sensitivity of this vector magnetometer is not ideal in itself, because during each frequency hopping addressing process, the sensor will temporarily lose the magnetic field component transverse to the selected axis. Any dead time associated with vector field measurement, including the time of switching microwave frequency or driving away from resonance, will reduce the measurement speed and bandwidth. Therefore, both the traditional frequency sweep method and the frequency hopping method have the problem of long detection time and inability to achieve real-time synchronous detection, which also causes the unsatisfactory sensitivity, dynamic range and bandwidth parameters of the magnetometer.

[0004] Therefore, how to achieve synchronous real-time measurement of the vector magnetic field on the NV color center magnetometer has become an important technical problem that needs to be urgently solved by technicians in this field. Summary of the invention

[0005] The purpose of this application is to provide a synchronous vector magnetic field measurement device, method, equipment, medium and product based on diamond NV color center, which can synchronously measure all Cartesian components of the dynamic magnetic field in the NV color center ensemble in real time. It is applied to vector NV magnetometer to optimize parameters such as sensitivity, bandwidth and dynamic range, and reduce detection time.

[0006] To achieve the above objectives, this application provides the following solutions:

[0007] In a first aspect, the present application provides a synchronous vector magnetic field measurement device based on diamond NV color centers, comprising:

[0008] A first microwave source, a second microwave source, a third microwave source, a fourth microwave source, a signal generator, a combiner, a diamond NV color center magnetometer probe, an analog-to-digital converter, a first lock-in amplifier, a second lock-in amplifier, a third lock-in amplifier, a fourth lock-in amplifier, and a processor;

[0009] The first microwave source, the second microwave source, the third microwave source, the fourth microwave source and the signal generator are all connected to the combiner; the combiner, the diamond NV color center magnetometer probe and the analog-to-digital converter are connected in sequence; the first phase-locked amplifier, the second phase-locked amplifier, the third phase-locked amplifier and the fourth phase-locked amplifier are all connected to the analog-to-digital converter; the first phase-locked amplifier, the second phase-locked amplifier, the third phase-locked amplifier and the fourth phase-locked amplifier are also connected to the processor.

[0010] In the second aspect, based on the above-mentioned synchronous vector magnetic field measurement device based on diamond NV color center, the present application further provides a synchronous vector magnetic field measurement method based on diamond NV color center, and the synchronous vector magnetic field measurement method based on diamond NV color center specifically includes:

[0011] Construct the magnetic field Cartesian coordinate system of the NV magnetometer;

[0012] Using a first microwave source, a second microwave source, a third microwave source and a fourth microwave source to generate four different microwave modulation signals to apply excitation signals to the diamond at different frequencies, so that information from multiple NV directions is encoded in separate frequency bands, and is measured on an optical detector in a diamond NV color center magnetometer probe to obtain a voltage signal;

[0013] Based on the voltage signal, a first lock-in amplifier, a second lock-in amplifier, a third lock-in amplifier, and a fourth lock-in amplifier are used to perform phase-locked demodulation and filtering to extract a signal related to each NV direction, so as to obtain a voltage offset of different NV axes;

[0014] Based on the voltage offset of different NV axes, the voltage offset of different NV axes is converted into frequency offset by demodulating the slope of the zero crossing point of the curve to obtain the frequency changes of four NV axes;

[0015] Determine the relationship between the change in the frequency of the four NV axes and the change in the three-axis magnetic field components;

[0016] Determine an effective gyromagnetic ratio matrix based on the change relationship;

[0017] Calculating a left pseudo-inverse matrix of the effective gyromagnetic ratio matrix;

[0018] The dynamic magnetic field components are calculated based on the left pseudo-inverse matrix.

[0019] Optionally, constructing the magnetic field Cartesian coordinate system of the NV magnetometer specifically comprises the following steps:

[0020] Place the diamond NV color center magnetometer probe on a non-magnetic turntable at the center of the Holm-Heitz coil in a magnetic shielding barrel, apply a magnetic field in the z-axis direction to the Holm-Heitz coil, slowly rotate the diamond NV color center magnetometer probe on the non-magnetic turntable, and record the offset frequency changes of the four NV axes. When the offset frequency changes corresponding to the four NV axes are the same, it means that the z-axis of the diamond NV color center magnetometer probe is aligned with the z-axis of the Holm-Heitz coil. Mark the z-axis angle direction on the diamond NV color center magnetometer probe to obtain the z-axis in the Cartesian coordinate system of the magnetic field.

[0021] Only apply the magnetic field in the x-axis direction to the Holm-Heitz coil, keep the z-axis direction of the diamond NV color center magnetometer probe unchanged, and slowly rotate the diamond NV color center magnetometer probe. When the frequency changes of the four NV axis offsets are the same, it means that the x-axis of the diamond NV color center magnetometer probe coincides with the x-axis of the Holm-Heitz coil. Mark the x-axis direction on the diamond NV color center magnetometer probe to obtain the x-axis in the Cartesian coordinate system of the magnetic field.

[0022] Only apply the magnetic field in the y-axis direction to the Holm-Heitz coil, keep the z-axis direction of the diamond NV color center magnetometer probe unchanged, and slowly rotate the diamond NV color center magnetometer probe. When the changes in the offset frequencies of the four NV axes are the same, it means that the y-axis of the diamond NV color center magnetometer probe coincides with the y-axis of the Holm-Heitz coil. Mark the y-axis direction on the diamond NV color center magnetometer probe to obtain the y-axis in the Cartesian coordinate system of the magnetic field.

[0023] Optionally, determining the relationship between the frequency changes of the four NV axes and the change of the three-axis magnetic field components specifically includes the following steps:

[0024] The diamond NV color center magnetometer probe was placed in the uniform magnetic field section at the center of the Helmholtz coil, and the Helmholtz coil was calibrated with a magnetic field of 0.1-1A using a three-axis fluxgate magnetometer;

[0025] The Helmholtz coil was aligned along a defined x-axis relative to the diamond NV color center magnetometer probe head, and the frequency peak shift was tracked as the current was increased in steps of 0.1 A to apply a defined bias magnetic field;

[0026] The Helmholtz coil was aligned along a defined y-axis relative to the diamond NV color center magnetometer probe head, and the frequency peak shift was tracked as the current was increased in steps of 0.1 A to apply a defined bias magnetic field;

[0027] The Helmholtz coil was aligned along a defined z-axis relative to the diamond NV color center magnetometer probe head, and the frequency peak shift was tracked as the current was increased in steps of 0.1 A to apply a defined bias magnetic field;

[0028] A linear fit is performed on all four peaks in each axis to determine the relationship between the frequency changes of the four NV axes and the changes in the three-axis magnetic field components.

[0029] Optionally, the specific expression of the relationship between the change in the frequency of the four NV axes and the change in the three-axis magnetic field components is as follows:

[0030]

[0031] Where Δv NV1 , Δv NV2 , Δv NV3 , Δv NV4 is the offset frequency of the NV axis, B x , B y , B z are the magnetic field components in the frame defined around the diamond NV color center magnetometer probe, and A is the effective gyromagnetic ratio matrix.

[0032] Optionally, the effective gyromagnetic ratio matrix is ​​determined based on the change relationship by using the following formula:

[0033]

[0034] Where Δv NV1 , Δv NV2 , Δv NV3 , Δv NV4 is the offset frequency of the NV axis, B x , B y , B z are the magnetic field components in the frame defined around the diamond NV color center magnetometer probe, and A is the effective gyromagnetic ratio matrix.

[0035] Optionally, the left pseudo-inverse matrix of the effective gyromagnetic ratio matrix is ​​calculated by using the following formula:

[0036]

[0037] Where Δv NV1 , Δv NV2 , Δv NV3 , Δv NV4 is the offset frequency of the NV axis, B x , B y , B z are the magnetic field components in the frame defined around the diamond NV color center magnetometer probe, A + is the left pseudo-inverse matrix.

[0038] In a third aspect, the present application provides a computer device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of any of the above-mentioned synchronous vector magnetic field measurement methods based on diamond NV color centers.

[0039] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the above-mentioned synchronous vector magnetic field measurement methods based on diamond NV color centers.

[0040] In a fifth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the steps of any of the above-mentioned synchronous vector magnetic field measurement methods based on diamond NV color centers.

[0041] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0042] The present application provides a synchronous vector magnetic field measurement device, method, equipment, medium and product based on diamond NV color center. Compared with other types of magnetometers, diamond nitrogen vacancy (NV) magnetometer has high sensitivity, easy integration and strong working adaptability, and can meet the high-precision requirements in practical applications; and diamond has high temperature stability and small shape change, so the environment has little effect on the NV magnetometer; due to the natural vector characteristics of the ensemble NV color center, the NV magnetometer has greater advantages in measuring vector magnetic fields than other magnetometers; compared with the existing NV magnetometer application, the NV magnetometer using the synchronous real-time vector magnetic field measurement method has high sensitivity, high resolution, high dynamic range, and the system is simple and easy to maintain, which provides new possibilities for applications such as geomagnetic navigation and underwater detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 This is a schematic diagram of a synchronous vector magnetic field measurement device based on diamond NV color centers in one embodiment of the present application;

[0045] Figure 2 A schematic diagram of a flow chart of a synchronous vector magnetic field measurement method based on diamond NV color centers provided in one embodiment of the present application;

[0046] Figure 3 A schematic diagram of a three-axis solution based on an NV magnetometer provided in an embodiment of the present application;

[0047] Figure 4 A diamond unit cell diagram provided for an embodiment of the present application;

[0048] Figure 5 A diagram of a calibration device provided in an embodiment of the present application;

[0049] Figure 6 ODMR and demodulation curve diagram thereof provided in an embodiment of the present application;

[0050] Figure 7 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0053] like Figure 1 As shown, the present application provides a synchronous vector magnetic field measurement device based on diamond NV color center, including:

[0054] A first microwave source 1, a second microwave source 2, a third microwave source 3, a fourth microwave source 4, a signal generator 5, a combiner 6, a diamond NV color center magnetometer probe 7, an analog-to-digital converter 13, a first lock-in amplifier 8, a second lock-in amplifier 9, a third lock-in amplifier 10, a fourth lock-in amplifier 11, and a processor 12;

[0055] The first microwave source 1, the second microwave source 2, the third microwave source 3, the fourth microwave source 4 and the signal generator 5 are all connected to the combiner 6; the combiner 6, the diamond NV color center magnetometer probe 7 and the analog-to-digital converter 13 are connected in sequence; the first phase-locked amplifier 8, the second phase-locked amplifier 9, the third phase-locked amplifier 10 and the fourth phase-locked amplifier 11 are all connected to the analog-to-digital converter 13; the first phase-locked amplifier 8, the second phase-locked amplifier 9, the third phase-locked amplifier 10 and the fourth phase-locked amplifier 11 are also connected to the processor 12.

[0056] The first microwave source 1, the second microwave source 2, the third microwave source 3 and the fourth microwave source 4 are used to generate four microwave signals, which are mixed with the modulated carrier emitted by the signal generator 5. These signals are amplified and combined by the combiner 6, and then radiated to the diamond by the microwave antenna coil. The diamond NV color center magnetometer probe 7 converts the measured signal into a digital signal through the ADC analog-to-digital converter 13 and inputs it into the first phase-locked amplifier 8, the second phase-locked amplifier 9, the third phase-locked amplifier 10 and the fourth phase-locked amplifier 11 for detection and demodulation of the signal transmitted by the probe, and finally feeds the result back to the processor 12.

[0057] Figure 2 A flow chart of a synchronous vector magnetic field measurement method based on diamond NV color center provided in an embodiment of the present application, Figure 2 , the method in this application comprises the following steps:

[0058] Step 101: Construct the magnetic field Cartesian coordinate system of the NV magnetometer.

[0059] When measuring the vector magnetic field of a diamond nitrogen vacancy (NV) color center magnetometer, an orthogonal three-axis coordinate system must be constructed to project the four axial magnetic field components of the NV color center onto the x, y, and z coordinate axes. 3V Symmetry, such as Figure 3 As shown, the NV axes are located at

[111] , Based on this, a weak magnetic detection coordinate system of the ensemble diamond NV color center under laboratory coordinates, namely the magnetic field Cartesian coordinate system of the NV magnetometer, is constructed to realize the relationship between the resonant frequency drift under different NV axis magnetic field strengths and the external test magnetic field. The coordinate system model is as follows: Figure 3On this basis, the ensemble diamond surface was selected as the X and Y planes of the coordinate system. The Z axis is perpendicular to the diamond surface, and the x, y, and z axes of the coordinate system are along

[001] ,

[110] , Crystal orientation is established, the structure of diamond is like Figure 4 As shown. Observe from the perspective of the z-axis (i.e. looking from top to bottom). The projections of each NV axis on the x-axis-y-axis plane show the same symmetry. When viewed from the x-axis or y-axis direction of the coordinate system, the NV axes show the characteristics of overlapping in pairs. Therefore, when the diamond sample is placed in a vector magnetic field and its coordinate system axis is aligned with the magnetic field direction, if the magnetic field is only applied along the z-axis direction, then the offset frequency changes of all NV axes should be equal. Similarly, when the magnetic field is applied along the x-axis or y-axis direction, it should be observed that the NV axis offset frequency changes show a pairwise identical pattern.

[0060] The diamond NV color center magnetometer probe is placed on a non-magnetic turntable 16 at the center of the Holmheitz coil 15 in the magnetic shielding barrel 14. Figure 5 , apply a magnetic field in the z-axis direction to the coil, slowly and randomly rotate the diamond NV color center magnetometer probe on the turntable, and observe the offset frequency changes of the four NV axes. When the offset frequency changes corresponding to the four NV axes are the same, it means that the sensor probe z-axis is aligned with the coil z-axis, and the z-axis angle direction is marked on the diamond NV color center magnetometer probe; only apply a magnetic field in the x-axis direction to the coil, keep the sensor z-axis direction unchanged and slowly rotate the probe. When the four NV axis offset frequency changes are the same, it means that the sensor x-axis coincides with the coil x-axis, and the x-axis direction is marked on the diamond NV color center magnetometer probe. The same applies to the y-axis.

[0061] Step 102: Use the first microwave source, the second microwave source, the third microwave source and the fourth microwave source to generate four different microwave modulation signals to apply excitation signals to the diamond at different frequencies, so that information from multiple NV directions is encoded in separate frequency bands, and is measured on an optical detector in the diamond NV color center magnetometer probe to obtain a voltage signal.

[0062] Step 103: Based on the voltage signal, use the first lock-in amplifier, the second lock-in amplifier, the third lock-in amplifier and the fourth lock-in amplifier to perform phase-locked demodulation and filtering to extract the signal related to each NV direction to obtain the voltage offset of different NV axes.

[0063] In the high-precision measurement area, the sensing bandwidth can be moved from the DC frequency to the high frequency band by up-modulation, thereby effectively reducing the adverse effects of 1 / f noise in the low frequency band. A common method in diamond NV color center magnetometer experiments is to apply frequency or phase modulation to the MWs that process spin transitions, which allows the magnetic field information to be encoded in the frequency band around the modulation frequency. Multiplexing extensions using this scheme, such as Figure 1 As shown, four different microwave modulation signals f NV1 、f NV2 、f NV3 、f NV4 Applying excitation signals to diamond at different frequencies allows voltage information from multiple NV directions to be encoded in separate frequency bands and measured on a single optical detector. Then, phase-locked demodulation and filtering extract the signal associated with each NV direction. Figure 6 ), and the resonant frequency corresponds to the zero point of the demodulation curve. The ODMR demodulation curve shows good linearity, and the resonant frequency is linearly correlated within the linear range. This positive correlation is further reflected in the demodulation curve. The frequency k of the zero point of the demodulation curve is the ratio of the NV axis offset voltage to the offset frequency. where the voltage offset difference ΔU NV To monitor the change in the magnetic field, by measuring the voltage changes of different NV axes, all components of the dynamic magnetic field can be measured accurately and quickly.

[0064] Step 104: Based on the voltage offsets of different NV axes, the voltage offsets of different NV axes are converted into frequency offsets by demodulating the slope of the zero-crossing point of the curve to obtain four NV axis frequency changes.

[0065] Step 105: Determine the relationship between the frequency changes of the four NV axes and the changes in the three-axis magnetic field components.

[0066] Step 106: Determine an effective gyromagnetic ratio matrix based on the change relationship.

[0067] The purpose of this step is to convert the frequency changes of the four NV axes detected in step 103 into magnetic field changes in the three-axis coordinate system established in the first step, converting the four-axis to three-axis, and converting the four-axis frequency changes into three-axis magnetic field changes. The specific steps are as follows:

[0068] Vector solution requires establishing the relationship between the four NV axis offset frequencies and the three magnetic field intensity vector components. The sensor probe is placed in the uniform magnetic field section at the center of the Helmholtz coil, and the coil is calibrated with a 0.1-1A magnetic field using a three-axis fluxgate magnetometer. The coil is aligned along the defined x-axis relative to the head of the diamond NV color center magnetometer probe, and as the current increases in steps of 0.1A to apply a determined bias magnetic field, the frequency peak shift is tracked, and the y-axis and z-axis are operated in the same way. All four peaks in each axis are linearly fitted to determine the relationship between the peak center frequency and the increase in the external field. Based on the determined bias magnetic field parameters, that is, the magnitude and direction of the applied bias magnetic field, and the relationship between the NV center frequency offset and the magnetic field change, the effective gyromagnetic ratio matrix (hereinafter referred to as the A matrix) is derived:

[0069]

[0070] Where Δv NV1 , Δv NV2 , Δv NV3 , Δv NV4 is the offset frequency of the NV axis, B x , B y , B z are the magnetic field components in the frame defined around the sensor head, respectively.

[0071] Using the NV center spin Hamiltonian and the measured bias magnetic field parameters, the expression of the A matrix is ​​derived. The general form of the A matrix is:

[0072]

[0073] The elements in the matrix are the partial derivatives of the different axial resonance frequencies of the NV center with respect to the magnetic field components in the Cartesian coordinate system. The rows of the A matrix correspond to the four different crystallographic directions of the NV center.

[0074] Step 107: Calculate the left pseudo-inverse matrix of the effective gyromagnetic ratio matrix.

[0075] Furthermore, after a large number of experiments to measure the experimental data, and after calculating the A matrix through multiple numerical fittings, the left pseudo-inverse matrix A of A is calculated using mathematical methods + , using the A matrix and the measured ODMR resonance peak frequency change and magnetic field change, through A + Calculate the dynamic magnetic field components in the laboratory coordinate system:

[0076]

[0077] Finally, by measuring different magnetic field changes and using A + The conversion is performed and compared with the fluxgate measurement results to verify the validity of the A matrix.

[0078] Through the above operations, the A matrix can be accurately determined and used to complete synchronous real-time vector measurement of the dynamic magnetic field, thereby improving the measurement efficiency and providing new possibilities for real-time magnetic induction and imaging.

[0079] Step 108: Calculate the dynamic magnetic field component based on the left pseudo-inverse matrix.

[0080] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 7 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store synchronous vector magnetic field measurement data based on diamond NV color centers. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a synchronous vector magnetic field measurement method based on diamond NV color centers is implemented.

[0081] Those skilled in the art will understand that Figure 7 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0082] In an exemplary embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0083] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0084] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0085] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0086] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0087] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0088] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0089] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A synchronous vector magnetic field measurement device based on diamond NV color center, characterized in that: The synchronous vector magnetic field measurement device based on diamond NV color center includes: A first microwave source, a second microwave source, a third microwave source, a fourth microwave source, a signal generator, a combiner, a diamond NV color center magnetometer probe, an analog-to-digital converter, a first lock-in amplifier, a second lock-in amplifier, a third lock-in amplifier, a fourth lock-in amplifier, and a processor; The first microwave source, the second microwave source, the third microwave source, the fourth microwave source and the signal generator are all connected to the combiner; the combiner, the diamond NV color center magnetometer probe and the analog-to-digital converter are connected in sequence; the first phase-locked amplifier, the second phase-locked amplifier, the third phase-locked amplifier and the fourth phase-locked amplifier are all connected to the analog-to-digital converter; the first phase-locked amplifier, the second phase-locked amplifier, the third phase-locked amplifier and the fourth phase-locked amplifier are also connected to the processor.

2. A synchronous vector magnetic field measurement method based on diamond NV color center, characterized in that: The synchronous vector magnetic field measurement method based on diamond NV color center specifically includes: Construct the magnetic field Cartesian coordinate system of the NV magnetometer; Using a first microwave source, a second microwave source, a third microwave source and a fourth microwave source to generate four different microwave modulation signals to apply excitation signals to the diamond at different frequencies, so that information from multiple NV directions is encoded in separate frequency bands, and is measured on an optical detector in a diamond NV color center magnetometer probe to obtain a voltage signal; Based on the voltage signal, a first lock-in amplifier, a second lock-in amplifier, a third lock-in amplifier, and a fourth lock-in amplifier are used to perform phase-locked demodulation and filtering to extract a signal related to each NV direction, so as to obtain a voltage offset of different NV axes; Based on the voltage offset of different NV axes, the voltage offset of different NV axes is converted into frequency offset by demodulating the slope of the zero crossing point of the curve to obtain the frequency changes of four NV axes; Determine the relationship between the change in the frequency of the four NV axes and the change in the three-axis magnetic field components; Determine an effective gyromagnetic ratio matrix based on the change relationship; Calculating a left pseudo-inverse matrix of the effective gyromagnetic ratio matrix; The dynamic magnetic field components are calculated based on the left pseudo-inverse matrix.

3. The synchronous vector magnetic field measurement method based on diamond NV color center according to claim 2 is characterized in that: The construction of the magnetic field Cartesian coordinate system of the NV magnetometer specifically includes the following steps: Place the diamond NV color center magnetometer probe on a non-magnetic turntable at the center of the Holm-Heitz coil in a magnetic shielding barrel, apply a magnetic field in the z-axis direction to the Holm-Heitz coil, slowly rotate the diamond NV color center magnetometer probe on the non-magnetic turntable, and record the offset frequency changes of the four NV axes. When the offset frequency changes corresponding to the four NV axes are the same, it means that the z-axis of the diamond NV color center magnetometer probe is aligned with the z-axis of the Holm-Heitz coil. Mark the z-axis angle direction on the diamond NV color center magnetometer probe to obtain the z-axis in the Cartesian coordinate system of the magnetic field. Only apply the magnetic field in the x-axis direction to the Holm-Heitz coil, keep the z-axis direction of the diamond NV color center magnetometer probe unchanged, and slowly rotate the diamond NV color center magnetometer probe. When the frequency changes of the four NV axis offsets are the same, it means that the x-axis of the diamond NV color center magnetometer probe coincides with the x-axis of the Holm-Heitz coil. Mark the x-axis direction on the diamond NV color center magnetometer probe to obtain the x-axis in the Cartesian coordinate system of the magnetic field. Only apply the magnetic field in the y-axis direction to the Holm-Heitz coil, keep the z-axis direction of the diamond NV color center magnetometer probe unchanged, and slowly rotate the diamond NV color center magnetometer probe. When the changes in the offset frequencies of the four NV axes are the same, it means that the y-axis of the diamond NV color center magnetometer probe coincides with the y-axis of the Holm-Heitz coil. Mark the y-axis direction on the diamond NV color center magnetometer probe to obtain the y-axis in the Cartesian coordinate system of the magnetic field.

4. The synchronous vector magnetic field measurement method based on diamond NV color center according to claim 2, characterized in that: Determining the relationship between the frequency changes of the four NV axes and the change of the three-axis magnetic field components specifically includes the following steps: The diamond NV color center magnetometer probe was placed in the uniform magnetic field section at the center of the Helmholtz coil, and the Helmholtz coil was calibrated with a magnetic field of 0.1-1A using a three-axis fluxgate magnetometer; The Helmholtz coil was aligned along a defined x-axis relative to the diamond NV color center magnetometer probe head, and the frequency peak shift was tracked as the current was increased in steps of 0.1 A to apply a defined bias magnetic field; The Helmholtz coil was aligned along a defined y-axis relative to the diamond NV color center magnetometer probe head, and the frequency peak shift was tracked as the current was increased in steps of 0.1 A to apply a defined bias magnetic field; The Helmholtz coil is aligned along a defined z-axis relative to the diamond NV color center magnetometer probe head, and the frequency peak shift is tracked as the current is increased in steps of 0.1A to apply a defined bias magnetic field; a linear fit is performed on all four peaks in each axial direction to determine the relationship between the change in the four NV axis frequencies and the change in the three-axis magnetic field components.

5. The synchronous vector magnetic field measurement method based on diamond NV color center according to claim 2, characterized in that: The specific expression of the relationship between the change in the frequency of the four NV axes and the change in the three-axis magnetic field components is as follows: Where Δv NV1 , Δv NV2 , Δv NV3 , Δv NV4 is the offset frequency of the NV axis, B x , B y , B z are the magnetic field components in the frame defined around the diamond NV color center magnetometer probe, and A is the effective gyromagnetic ratio matrix.

6. The synchronous vector magnetic field measurement method based on diamond NV color center according to claim 2, characterized in that: The following formula is specifically used to determine the effective gyromagnetic ratio matrix based on the change relationship: Where Δv NV1 , Δv NV2 , Δv NV3 , Δv NV4 is the offset frequency of the NV axis, B x , B y , B z are the magnetic field components in the frame defined around the diamond NV color center magnetometer probe, and A is the effective gyromagnetic ratio matrix.

7. The synchronous vector magnetic field measurement method based on diamond NV color center according to claim 2, characterized in that: The left pseudo-inverse matrix of the effective gyromagnetic ratio matrix is ​​calculated by the following formula: Where Δv NV1 , Δv NV2 , Δv NV3 , Δv NV4 is the offset frequency of the NV axis, B x , B y , B z are the magnetic field components in the frame defined around the diamond NV color center magnetometer probe, A + is the left pseudo-inverse matrix.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the synchronous vector magnetic field measurement method based on diamond NV color center described in any one of claims 2-7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the synchronous vector magnetic field measurement method based on diamond NV color center described in any one of claims 2 to 7 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the synchronous vector magnetic field measurement method based on diamond NV color center described in any one of claims 2 to 7 are implemented.

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