Simple diamond NV color center four-axis measuring method and device, terminal equipment and storage medium

Abstract

The invention discloses a simple diamond NV color center four-axis measuring method and device, terminal equipment and a storage medium, and relates to the technical field of vector sensor sensitive axis space direction calibration, and the method comprises the steps: obtaining an ODMR spectrum of a to-be-measured diamond NV color center; adjusting the direction of the applied magnetic field, determining all the directions of the applied magnetic field perpendicular to the first axial direction of the NV color center of the to-be-measured diamond based on the formant condition in the ODMR spectrum, obtaining a first plane, and then determining the first axial direction; adjusting the direction of the external magnetic field in the first plane, and determining a second plane when the formant of the ODMR spectrum changes; adjusting the direction of the external magnetic field in a second plane, and determining a second axial direction when the formant of the ODMR spectrum changes again; and calculating a third axial direction and a fourth axial direction of the NV color center of the diamond to be measured according to the first axial direction and the second axial direction. By means of the method, the four axial directions of the NV color center of the diamond can be measured at a time.

Description

Technical Field

[0001] The present invention relates to the technical field of calibration of the spatial direction of the sensitive axis of a vector sensor, and particularly to a simple method, device, terminal device and storage medium for four-axis determination of a diamond NV center. Background Art

[0002] The diamond NV center is a structural defect existing in the diamond lattice. The carbon atoms themselves should be arranged according to the standard tetrahedron. The addition of a nitrogen atom will replace two adjacent carbon atoms, forming a nitrogen-vacancy structure, resulting in an unpaired electron around this nitrogen atom. This lattice defect has special fluorescence characteristics. Under the irradiation of a laser (such as 532 nm), it will emit fluorescence, and this fluorescence is very stable and can be observed at room temperature. Coupled with the physical and chemical stability of diamond itself, it can be used for high-precision measurement of physical fields such as electromagnetic fields and temperatures, and is an important quantum precision measurement technology.

[0003] According to the tetrahedral structure of the diamond lattice, the NV center may have four axes. The basic principle of the existing methods for determining the NV center axis is to change the direction and magnitude of the externally applied magnetic field. The diamond NV center will emit different fluorescence, and the axis is determined by observing the change in the splitting of the resonance peaks in the ODMR spectrum. Specifically, it can be divided into two categories. One is to directly change the direction of the externally applied magnetic field. When a certain axis of the diamond NV center is parallel to the externally applied magnetic field, only two sets of resonance peaks will appear in the ODMR spectrum. Fine-tune the magnetic field direction, and the magnetic field direction corresponding to the maximum fluorescence intensity is taken as a certain axis of the diamond NV center (simply referred to as the parallel method).

[0004] The other is to change the vector of the externally applied magnetic field. Each magnetic field vector will obtain an ODMR spectrum, which is converted into the projection of the magnetic field on each axis of the NV center. Repeat a number of experiments to obtain a set of corresponding relationships between the externally applied magnetic field vector and the magnetic field vector of the NV center axis, and obtain the coordinate transformation matrix from the space coordinate system to the diamond NV center coordinate system through the least squares solution of the overdetermined linear equations (simply referred to as the equation method).

[0005] However, there are still conflicts in the existing technology in terms of the number of axes determined for the diamond NV center and the complexity of scheme implementation. The parallel method can only measure one NV center axis at a time. If all four axes need to be measured, repeated experiments are required. The equation method can obtain all four NV center axes, but it is necessary to establish overdetermined linear equations. To ensure the measurement accuracy, multiple repeated experiments are also required, resulting in low measurement efficiency. Summary of the Invention

[0006] An embodiment of the present invention provides a simple method, device, terminal device and storage medium for measuring four axial directions of a diamond NV center. The present invention can solve the problem that the prior art cannot achieve the measurement of four axial directions of a diamond NV center at one time.

[0007] An embodiment of the present invention provides a simple method for measuring four axial directions of a diamond NV center, including:

[0008] Applying microwave and an external magnetic field to the diamond to be measured, and obtaining the ODMR spectrum of the NV center of the diamond to be measured in real time by the frequency sweep method;

[0009] Adjusting the direction of the external magnetic field. When the resonance peaks in the first preset frequency range in the ODMR spectrum are split into four resonance peaks with amplitudes less than the first preset threshold, it is determined that the direction of the external magnetic field is perpendicular to the first axial direction of the NV center of the diamond to be measured;

[0010] Continuing to adjust the direction of the external magnetic field, determining at least 3 directions of the external magnetic field perpendicular to the first axial direction of the NV center of the diamond to be measured in the same plane; then determining the plane where the direction of the external magnetic field perpendicular to the first axial direction of the NV center of the diamond to be measured is located as the first plane, and determining the first axial direction of the NV center of the diamond to be measured according to the first plane;

[0011] Adjusting the direction of the external magnetic field in the first plane. When the resonance peaks with amplitudes greater than the second preset threshold in the second preset frequency range in the ODMR spectrum are reduced from three groups to two groups, it is determined that the current direction of the external magnetic field is parallel to the second plane where the first axial direction and the second axial direction of the NV center of the diamond to be measured are located, and then the second plane is determined; adjusting the direction of the external magnetic field in the second plane. When the resonance peaks in the first preset frequency range in the ODMR spectrum are split into four resonance peaks with amplitudes less than the first preset threshold again, it is determined that the current direction of the external magnetic field is perpendicular to the second axial direction of the NV center of the diamond to be measured, and then the second axial direction of the NV center of the diamond to be measured is determined;

[0012] Calculating the third axial direction and the fourth axial direction of the NV center of the diamond to be measured according to the determined first axial direction and the second axial direction of the NV center of the diamond to be measured, so as to determine all the axial directions of the NV center of the diamond to be measured.

[0013] Further, the applying microwave to the diamond to be measured includes:

[0014] Controlling the microwave antenna to apply microwave to the diamond to be measured placed at the strongest point of the microwave signal; wherein, the center frequency of the microwave antenna is set to 2.87 GHz.

[0015] Further, the adjusting the direction of the external magnetic field includes:

[0016] Controlling the permanent magnet to adjust the direction of the external magnetic field.

[0017] Further, calculating the third axial direction and the fourth axial direction of the diamond NV color center to be measured according to the determined first axial direction and second axial direction of the diamond NV color center to be measured includes:

[0018] Determining the angle between the axial directions according to the lattice structure of the regular tetrahedron of the diamond to be measured;

[0019] Based on the determined first axial direction and second axial direction of the diamond NV color center to be measured and the angle between the axial directions, calculating the third axial direction and the fourth axial direction of the diamond NV color center to be measured.

[0020] Another embodiment of the present invention provides a simple device for measuring four axial directions of a diamond NV color center, including: an ODMR spectrum acquisition module, a first axial direction preliminary determination module, a first axial direction determination module, a second axial direction determination module, and a remaining axial direction determination module;

[0021] The ODMR spectrum acquisition module is used to apply microwaves and an external magnetic field to the diamond to be measured, and obtain the ODMR spectrum of the diamond NV color center to be measured in real time by the frequency sweep method;

[0022] The first axial direction preliminary determination module is used to adjust the direction of the external magnetic field. When the resonance peaks in the first preset frequency range in the ODMR spectrum are split into four resonance peaks with amplitudes less than the first preset threshold, it is determined that the direction of the external magnetic field is perpendicular to the first axial direction of the diamond NV color center to be measured;

[0023] The first axial direction determination module is used to continue to adjust the direction of the external magnetic field, determine at least 3 directions of the external magnetic field perpendicular to the first axial direction of the diamond NV color center to be measured in the same plane; connect and determine the plane where the direction of the external magnetic field perpendicular to the first axial direction of the diamond NV color center to be measured is located as the first plane, and determine the first axial direction of the diamond NV color center to be measured according to the first plane;

[0024] The second axial direction determination module is used to adjust the direction of the external magnetic field in the first plane. When the resonance peaks with amplitudes greater than the second preset threshold in the second preset frequency range in the ODMR spectrum are reduced from three groups to two groups, it is determined that the current direction of the external magnetic field is parallel to the second plane where the first axial direction and the second axial direction of the diamond NV color center to be measured are located, and then the second plane is determined; adjust the direction of the external magnetic field in the second plane. When the resonance peaks in the first preset frequency range in the ODMR spectrum are split into four resonance peaks with amplitudes less than the first preset threshold again, it is determined that the current direction of the external magnetic field is perpendicular to the second axial direction of the diamond NV color center to be measured, and then the second axial direction of the diamond NV color center to be measured is determined;

[0025] The remaining axial direction determination module is configured to calculate the third axial direction and the fourth axial direction of the diamond NV color center to be measured according to the determined first axial direction and second axial direction of the diamond NV color center to be measured, so as to determine all the axial directions of the diamond NV color center to be measured.

[0026] Further, the ODMR spectrum acquisition module applies microwaves to the diamond to be measured, including:

[0027] Controlling the microwave antenna to apply microwaves to the diamond to be measured placed at the strongest point of the microwave signal; wherein, the center frequency of the microwave antenna is set to 2.87 GHz.

[0028] Further, the first axial direction preliminary determination module adjusts the direction of the externally applied magnetic field, including:

[0029] Controlling the permanent magnet to adjust the direction of the externally applied magnetic field.

[0030] Further, the remaining axial direction determination module includes an included angle determination unit and a third and fourth axial direction determination unit:

[0031] The included angle determination unit is configured to determine the included angle between the axial directions according to the lattice structure of the regular tetrahedron of the diamond to be measured;

[0032] The third and fourth axial direction determination unit is configured to calculate the third axial direction and the fourth axial direction of the diamond NV color center to be measured based on the determined first axial direction and second axial direction of the diamond NV color center to be measured and the included angle between the axial directions.

[0033] Another embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements a simple method for measuring the four axial directions of a diamond NV color center as described in any one of the above embodiments.

[0034] Another embodiment of the present invention provides a storage medium, which includes a stored computer program. When the computer program runs, it controls the device where the storage medium is located to execute a simple method for measuring the four axial directions of a diamond NV color center as described in any one of the above embodiments.

[0035] By implementing the present invention, the following beneficial effects are achieved:

[0036] An embodiment of the present invention provides a simple method for measuring the four axes of a diamond NV center. The method includes: obtaining the ODMR spectrum of the diamond NV center to be measured; adjusting the direction of the externally applied magnetic field. When the resonance peaks within the first preset frequency range in the ODMR spectrum split into four resonance peaks with amplitudes less than the first preset threshold, it is determined that the direction of the externally applied magnetic field is perpendicular to the first axis of the diamond NV center to be measured; continuing to adjust the direction of the externally applied magnetic field to determine at least 3 directions of the externally applied magnetic field that are perpendicular to the first axis of the diamond NV center to be measured and lie in the same plane; then determining the plane where the direction of the externally applied magnetic field perpendicular to the first axis of the diamond NV center to be measured is located as the first plane, and determining the first axis of the diamond NV center to be measured according to the first plane; adjusting the direction of the externally applied magnetic field within the first plane. When the resonance peaks with amplitudes greater than the second preset threshold within the second preset frequency range in the ODMR spectrum are reduced from three groups to two groups, it is determined that the current direction of the externally applied magnetic field is parallel to the second plane where the first axis and the second axis of the diamond NV center to be measured are located, and then the second plane is determined; adjusting the direction of the externally applied magnetic field within the second plane. When the resonance peaks within the first preset frequency range in the ODMR spectrum split into four resonance peaks with amplitudes less than the first preset threshold again, it is determined that the current direction of the externally applied magnetic field is perpendicular to the second axis of the diamond NV center to be measured, and then the second axis of the diamond NV center to be measured is determined; calculating the third axis and the fourth axis of the diamond NV center to be measured according to the determined first axis and the second axis of the diamond NV center to be measured, so as to determine all the axes of the diamond NV center to be measured. The present invention measures the axes of the diamond NV center by observing the changes in the splitting of the resonance peaks in the ODMR spectrum of the diamond under an externally applied magnetic field environment and a zero-field environment. A permanent magnet is used to apply a magnetic field to the diamond and change the direction of the magnetic field to determine all the axes of the diamond, achieving the measurement of the four axes of the diamond NV center in one go in a simple way without repeated operations, thus improving the measurement efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 FIG. is a schematic flowchart of a simple method for measuring the four axes of a diamond NV center provided by an embodiment of the present invention.

[0038] Figure 2 FIG. is a schematic diagram of the splitting of resonance peaks in the ODMR spectrum under zero-field conditions provided by an embodiment of the present invention.

[0039] Figure 3 FIG. is a schematic diagram of the splitting of all resonance peaks in the ODMR spectrum when the direction of the externally applied magnetic field is perpendicular to one of the axes of the diamond NV center provided by an embodiment of the present invention.

[0040] Figure 4 FIG. is a schematic diagram of the process of the reduction of resonance peaks in the ODMR spectrum when adjusting the direction of the externally applied magnetic field within the first plane provided by an embodiment of the present invention.

[0041] Figure 5 It is a schematic structural diagram of a simple diamond NV color center four-axis measurement device provided by an embodiment of the present invention. Detailed implementation manners

[0042] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0044] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, "a plurality of" means more than two unless otherwise specifically defined.

[0045] As Figure 1 shown, it is a schematic flow diagram of a simple diamond NV color center four-axis measurement method provided by an embodiment of the present invention, including the following steps:

[0046] Step S1: Apply microwave and an external magnetic field to the diamond to be measured, and obtain the ODMR spectrum of the NV color center of the diamond to be measured in real time by the frequency sweeping method.

[0047] In a preferred embodiment, applying microwave to the diamond to be measured includes:

[0048] Controlling the microwave antenna to apply microwave to the diamond to be measured placed at the strongest point of the microwave signal; wherein, the center frequency of the microwave antenna is set to 2.87 GHz.

[0049] In the present invention, microwave is applied to the diamond to be measured through the microwave antenna, the diamond to be measured is placed at the strongest point of the microwave signal, the microwave center frequency is set to 2.87 GHz, a permanent magnet is used to apply an external magnetic field to the diamond to be measured, and the ODMR spectrum of the NV color center of the diamond to be measured is obtained in real time by the frequency sweeping method.

[0050] An external magnetic field will cause the resonance peak of the diamond NV center to split. Since there are four axes of the diamond NV center, the resonance peak splitting caused by the external magnetic field is also in four groups. The splitting of the resonance peak is relatively obvious, and the maximum amplitude is relatively large. Without an external magnetic field, the resonance peak will also split in a zero-field environment. This splitting is relatively small, the maximum amplitude is relatively small, and it is closer to the center frequency of 2.87 GHz.

[0051] Schematically, as Figure 2 shown, it is the resonance peak splitting situation of the ODMR spectrum in the zero-field case in an embodiment.

[0052] Step S2: Adjust the direction of the external magnetic field. When the resonance peak in the first preset frequency range in the ODMR spectrum splits into four resonance peaks with amplitudes less than the first preset threshold, it is determined that the direction of the external magnetic field is perpendicular to the first axis of the diamond NV center to be measured;

[0053] In a preferred embodiment, the adjusting the direction of the external magnetic field includes:

[0054] Controlling the permanent magnet to adjust the direction of the external magnetic field.

[0055] In the present invention, the first preset frequency range is a relatively small preset frequency range close to the center frequency of 2.87 GHz. Schematically, the first preset frequency range can be 2.867 GHz - 2.876 GHz. In the first preset frequency range, the small resonance peak splitting in the zero-field environment can be observed, that is, four resonance peaks with amplitudes less than the first preset threshold appear. Schematically, the first preset threshold can be set to 0.3% of the baseline fluorescence intensity. For example, if the baseline fluorescence intensity is measured as 1000 a.u., then the first preset threshold corresponds to 3 a.u.; there are a total of four axes of the diamond NV center, and the first axis is one of the axes of the diamond NV center;

[0056] Specifically, by controlling the permanent magnet to adjust the direction of the external magnetic field and observing the resonance peak on the ODMR spectrum, when the direction of the external magnetic field is perpendicular to one of the axes of the diamond NV center to be measured, the influence of the external magnetic field on this axis of the diamond NV center to be measured is relatively small and can be approximated as a zero field. The small resonance peak splitting in the zero-field environment will occur. At this time, the resonance peak will become three large splittings in the external magnetic field environment and four small splittings in the zero-field environment. Only when a certain axis of the NV center is perpendicular to the magnetic field direction will four small splittings appear. Therefore, it can be judged whether there is an axis perpendicular to the magnetic field direction by observing whether four small splittings appear. Therefore, when the resonance peak in the first preset frequency range in the ODMR spectrum splits into four resonance peaks with amplitudes less than the first preset threshold, it is determined that the direction of the external magnetic field is perpendicular to the first axis of the diamond NV center to be measured at this time;

[0057] During the process of obtaining the ODMR spectrum, the acquisition time is proportional to the frequency range involved. That is, if the frequency range involved in the ODMR spectrum is larger, the time to obtain the ODMR spectrum will be longer. In this step, only the resonance peaks in a very small area near the central frequency need to be concerned, that is, those resonance peaks with amplitudes less than the first preset threshold. Therefore, the above steps only need to obtain the ODMR spectrum in a very small frequency range to operate, reducing the measurement time and improving the measurement efficiency.

[0058] Schematically, as Figure 3 shown, it is the splitting situation of all resonance peaks of the ODMR spectrum when the external magnetic field direction is perpendicular to one of the axial directions of the diamond NV center in an embodiment.

[0059] Step S3: Continue to adjust the external magnetic field direction to determine at least 3 external magnetic field directions perpendicular to the first axial direction of the diamond NV center to be measured in the same plane; then determine the plane where the external magnetic field direction perpendicular to the first axial direction of the diamond NV center to be measured is located as the first plane, and determine the first axial direction of the diamond NV center to be measured according to the first plane;

[0060] In the present invention, the first plane is the plane perpendicular to the first axial direction;

[0061] Specifically, by controlling the permanent magnet to continuously adjust the direction of the external magnetic field, keeping the resonance peaks in the first preset frequency range in the ODMR spectrum always split into four resonance peaks with amplitudes less than the first preset threshold. At this time, it indicates that the adjusted external magnetic field directions are all perpendicular to the first axial direction of the NV center. Determine at least 3 magnetic field directions perpendicular to the first axial direction of the NV center in the same plane, and then determine the plane where the external magnetic field direction perpendicular to the first axial direction of the diamond NV center to be measured is located as the first plane. Since the first plane is perpendicular to the first axial direction of the NV center, the first axial direction of the diamond NV center to be measured can be accurately determined through the normal direction of the first plane.

[0062] Step S4: Adjust the external magnetic field direction in the first plane. When the resonance peaks with amplitudes greater than the second preset threshold in the second preset frequency range in the ODMR spectrum are reduced from three groups to two groups, it is determined that the current external magnetic field direction is parallel to the second plane where the first axial direction and the second axial direction of the diamond NV center to be measured are located, and then the second plane is determined; adjust the external magnetic field direction in the second plane. When the resonance peaks in the first preset frequency range in the ODMR spectrum are split into four resonance peaks with amplitudes less than the first preset threshold again, it is determined that the current external magnetic field direction is perpendicular to the second axial direction of the diamond NV center to be measured, and then the second axial direction of the diamond NV center to be measured is determined;

[0063] In the present invention, the second preset frequency range is a preset frequency range in which all four groups of resonance peak splittings can be observed. Schematically, the second preset frequency range can be 2.82 GHz - 2.92 GHz, and the second preset threshold can be set to 0.5% of the baseline fluorescence intensity. For example, if the measured baseline fluorescence intensity is 1000 a.u., then the second preset threshold corresponds to 5 a.u.; the second axis is one of the four axes of the diamond NV center except the first axis; the second plane is the plane where the first axis and the second axis are located;

[0064] Specifically, in the first plane, the direction of the externally applied magnetic field is perpendicular to one of the axes of the diamond NV center to be measured. At this time, the resonance peaks will become three large splittings in the external magnetic field environment and four small splittings in the zero-field environment. By controlling the permanent magnet to adjust the direction of the externally applied magnetic field in the first plane, when the three resonance peaks with amplitudes greater than the second preset threshold generated by the external magnetic field on the ODMR spectrum slowly approach and finally merge into two resonance peaks with amplitudes greater than the second preset threshold, it is determined that the direction of the externally applied magnetic field is parallel to the plane formed by the first axis and the second axis of the diamond NV center to be measured, that is, parallel to the second plane, and the second plane is determined; among them, during the adjustment process, the ODMR spectrum is continuously observed. The four resonance peaks with amplitudes less than the first preset threshold caused by the zero-field environment always exist, indicating that the magnetic field remains moving in the first plane, and the reduction in the number of resonance peak splittings indicates that the magnetic field direction has become parallel to the plane where the axes of two NV centers are located, making their responses to the magnetic field the same and merging.

[0065] By controlling the permanent magnet to adjust the direction of the externally applied magnetic field in a single direction in the second plane, at this time, the four resonance peaks with amplitudes less than the first preset threshold caused by the zero-field environment will disappear. When the four resonance peaks with amplitudes less than the first preset threshold caused by the zero-field environment appear again, it indicates that the direction of the externally applied magnetic field is perpendicular to the second axis at this time. Based on the determined first axis and the second plane, the second axis is determined.

[0066] Schematically, as Figure 4 shown, it is the process of reducing the resonance peaks of the ODMR spectrum when adjusting the direction of the externally applied magnetic field in the first plane.

[0067] Step S5: According to the determined first axis and the second axis of the diamond NV center to be measured, calculate the third axis and the fourth axis of the diamond NV center to be measured, so as to determine all the axes of the diamond NV center to be measured.

[0068] In the present invention, the third axis and the fourth axis are the remaining two axes of the four axes of the diamond NV center to be measured except the first axis and the second axis;

[0069] In a preferred embodiment, calculating the third axis and the fourth axis of the diamond NV color center to be measured according to the determined first axis and second axis of the diamond NV color center to be measured includes:

[0070] Determining the angle between the axes according to the lattice structure of the regular tetrahedron of the diamond to be measured;

[0071] Based on the determined first axis and second axis of the diamond NV color center to be measured and the angle between the axes, calculating the third axis and the fourth axis of the diamond NV color center to be measured.

[0072] Specifically, according to the lattice structure of the regular tetrahedron of the diamond to be measured, the diamond NV color center to be measured has four axes, and the angle between every two axes is 109°28'. According to the positions of the first axis and the second axis and the angle information between the axes, the third axis and the fourth axis of the diamond NV color center to be measured can be obtained, thereby determining all the axes of the diamond NV color center to be measured.

[0073] Based on the above method item embodiment, the present invention correspondingly provides a device item embodiment;

[0074] As Figure 5 shown, it is a schematic structural diagram of a simple device for measuring the four axes of a diamond NV color center provided by an embodiment of the present invention, including:

[0075] ODMR spectrum acquisition module, first axis preliminary determination module, first axis determination module, second axis determination module and remaining axis determination module:

[0076] The ODMR spectrum acquisition module is used to apply microwaves and an external magnetic field to the diamond to be measured, and obtain the ODMR spectrum of the diamond NV color center to be measured in real time by the frequency sweep method;

[0077] The first axis preliminary determination module is used to adjust the direction of the external magnetic field. When the resonance peaks in the first preset frequency range in the ODMR spectrum are split into four resonance peaks with amplitudes less than the first preset threshold, it is determined that the direction of the external magnetic field is perpendicular to the first axis of the diamond NV color center to be measured;

[0078] The first axis determination module is used to continue to adjust the direction of the external magnetic field, determine at least 3 directions of the external magnetic field perpendicular to the first axis of the diamond NV color center to be measured in the same plane; then determine the plane where the direction of the external magnetic field perpendicular to the first axis of the diamond NV color center to be measured is located as the first plane, and determine the first axis of the diamond NV color center to be measured according to the first plane;

[0079] The second axial direction determination module is configured to adjust the direction of the externally applied magnetic field within the first plane. When the number of resonance peaks with amplitudes greater than the second preset threshold within the second preset frequency range in the ODMR spectrum is reduced from three groups to two groups, it is determined that the current direction of the externally applied magnetic field is parallel to the second plane where the first axial direction and the second axial direction of the diamond NV center to be measured are located, and then the second plane is determined. The direction of the externally applied magnetic field is adjusted within the second plane. When the resonance peaks within the first preset frequency range in the ODMR spectrum are split into four resonance peaks with amplitudes less than the first preset threshold again, it is determined that the current direction of the externally applied magnetic field is perpendicular to the second axial direction of the diamond NV center to be measured, and then the second axial direction of the diamond NV center to be measured is determined.

[0080] The remaining axial direction determination module is configured to calculate the third axial direction and the fourth axial direction of the diamond NV center to be measured according to the determined first axial direction and the second axial direction of the diamond NV center to be measured, so as to determine all the axial directions of the diamond NV center to be measured.

[0081] Further, the ODMR spectrum acquisition module applies microwaves to the diamond to be measured, including:

[0082] Controlling the microwave antenna to apply microwaves to the diamond to be measured placed at the point with the strongest microwave signal; wherein, the center frequency of the microwave antenna is set to 2.87 GHz.

[0083] Further, the first axial direction preliminary determination module adjusts the direction of the externally applied magnetic field, including:

[0084] Controlling the permanent magnet to adjust the direction of the externally applied magnetic field.

[0085] Further, the remaining axial direction determination module includes an included angle determination unit and a third and fourth axial direction determination unit:

[0086] The included angle determination unit is configured to determine the included angles between the axial directions according to the lattice structure of the regular tetrahedron of the diamond to be measured.

[0087] The third and fourth axial direction determination unit is configured to calculate the third axial direction and the fourth axial direction of the diamond NV center to be measured based on the determined first axial direction and the second axial direction of the diamond NV center to be measured and the included angles between the axial directions.

[0088] It can be understood that the above device item embodiments correspond to the method item embodiments of the present invention, and can implement a simple method for measuring the four axial directions of the diamond NV center provided by any one of the above method item embodiments of the present invention.

[0089] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. In addition, in the attached drawings of the device embodiments provided by the present invention, the connection relationships between the modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0090] Those skilled in the art can clearly understand that for the convenience and simplicity, the specific working process of the device described above can refer to the corresponding process in the foregoing method embodiment, and will not be elaborated here.

[0091] Another preferred embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements a simple diamond NV color center four-axis measurement method as described in any one of the above embodiments.

[0092] It should be noted that the terminal device mentioned here can be computing devices such as desktop computers, notebooks, palm computers, and cloud servers. The terminal device may include, but is not limited to, a processor and a memory. Those skilled in the art can understand that, for example, it may also include input and output devices, network access devices, buses, etc.

[0093] The so-called processor may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The processor is the control center of the terminal device, and connects various parts of the entire terminal device through various interfaces and lines.

[0094] The memory can be used to store the computer program. By running or executing the computer program stored in the memory and invoking the data stored in the memory, the processor realizes various functions of the terminal device. The memory mainly includes a program storage area and a data storage area. Among them, the program storage area can store an operating system, application programs required for at least one function, etc.; the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory can include high-speed random access memory and can also include non-volatile memory, such as a hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one magnetic disk storage device, flash memory device, or other volatile solid-state storage devices.

[0095] Another preferred embodiment of the present invention provides a storage medium. The storage medium includes a stored computer program. When the computer program runs, it controls the device where the storage medium is located to execute a simple diamond NV color center four-axis measurement method described in any one of the present invention.

[0096] The storage medium is a computer-readable storage medium. The computer program is stored in the computer-readable storage medium. When the computer program is executed by a processor, it can implement the steps of the above-mentioned various method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0097] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A simple method for four-axis measurement of diamond NV color centers, characterized in that, Including: Applying microwaves and an external magnetic field to the diamond to be measured, and obtaining the ODMR spectrum of the NV color center of the diamond to be measured in real time by the frequency sweep method; Adjusting the direction of the external magnetic field. When the resonance peaks in the first preset frequency range in the ODMR spectrum split into four resonance peaks with amplitudes less than the first preset threshold, it is determined that the direction of the external magnetic field is perpendicular to the first axis of the NV color center of the diamond to be measured; Continuing to adjust the direction of the external magnetic field to determine at least 3 directions of the external magnetic field perpendicular to the first axis of the NV color center of the diamond to be measured in the same plane; then determining the plane where the direction of the external magnetic field perpendicular to the first axis of the NV color center of the diamond to be measured is located as the first plane, and determining the first axis of the NV color center of the diamond to be measured according to the first plane; Adjusting the direction of the external magnetic field in the first plane. When the resonance peaks with amplitudes greater than the second preset threshold in the second preset frequency range in the ODMR spectrum are reduced from three groups to two groups, it is determined that the current direction of the external magnetic field is parallel to the second plane where the first axis and the second axis of the NV color center of the diamond to be measured are located, and then the second plane is determined; adjusting the direction of the external magnetic field in the second plane. When the resonance peaks in the first preset frequency range in the ODMR spectrum split into four resonance peaks with amplitudes less than the first preset threshold again, it is determined that the current direction of the external magnetic field is perpendicular to the second axis of the NV color center of the diamond to be measured, and then the second axis of the NV color center of the diamond to be measured is determined; Calculating the third axis and the fourth axis of the NV color center of the diamond to be measured according to the determined first axis and the second axis of the NV color center of the diamond to be measured, so as to determine all the axes of the NV color center of the diamond to be measured.

2. The simple four-axial measurement method for diamond NV color centers according to claim 1, characterized in that The applying microwaves to the diamond to be measured includes: Controlling the microwave antenna to apply microwaves to the diamond to be measured placed at the point with the strongest microwave signal; wherein, the center frequency of the microwave antenna is set to 2.87 GHz.

3. The simple four-axis measurement method for diamond NV color centers according to claim 2, characterized in that, The adjusting the direction of the external magnetic field includes: Controlling the permanent magnet to adjust the direction of the external magnetic field.

4. The simple four-axis measurement method for diamond NV color centers according to claim 3, characterized in that, The calculating the third axis and the fourth axis of the NV color center of the diamond to be measured according to the determined first axis and the second axis of the NV color center of the diamond to be measured includes: Determining the included angle between the axes according to the lattice structure of the regular tetrahedron of the diamond to be measured; Calculating the third axis and the fourth axis of the NV color center of the diamond to be measured based on the determined first axis and the second axis of the NV color center of the diamond to be measured and the included angle between the axes.

5. A simple diamond NV color center four-axis measurement device, characterized in that, Including: ODMR spectrum acquisition module, first axis preliminary determination module, first axis determination module, second axis determination module and remaining axis determination module: The ODMR spectrum acquisition module is used to apply microwaves and an external magnetic field to the diamond to be measured, and obtain the ODMR spectrum of the NV color center of the diamond to be measured in real time by the frequency sweep method; The first axis preliminary determination module is used to adjust the direction of the external magnetic field. When the resonance peaks in the first preset frequency range in the ODMR spectrum split into four resonance peaks with amplitudes less than the first preset threshold, it is determined that the direction of the external magnetic field is perpendicular to the first axis of the NV color center of the diamond to be measured; The first axial direction determination module is configured to continuously adjust the direction of the external magnetic field to determine at least three directions of the external magnetic field that are perpendicular to the first axial direction of the diamond NV center to be measured and lie in the same plane; then determine the plane where the direction of the external magnetic field perpendicular to the first axial direction of the diamond NV center to be measured is located as the first plane, and determine the first axial direction of the diamond NV center to be measured according to the first plane. The second axial direction determination module is configured to adjust the direction of the external magnetic field within the first plane. When the number of resonance peaks with amplitudes greater than the second preset threshold within the second preset frequency range in the ODMR spectrum is reduced from three groups to two groups, it is determined that the current direction of the external magnetic field is parallel to the second plane where the first axial direction and the second axial direction of the diamond NV center to be measured are located, and then the second plane is determined; adjust the direction of the external magnetic field within the second plane. When the resonance peaks within the first preset frequency range in the ODMR spectrum are split into four resonance peaks with amplitudes less than the first preset threshold again, it is determined that the current direction of the external magnetic field is perpendicular to the second axial direction of the diamond NV center to be measured, and then the second axial direction of the diamond NV center to be measured is determined. The remaining axial direction determination module is configured to calculate the third axial direction and the fourth axial direction of the diamond NV center to be measured according to the determined first axial direction and the second axial direction of the diamond NV center to be measured, so as to determine all the axial directions of the diamond NV center to be measured.

6. The simple diamond NV color center four-axis measurement device according to claim 5, characterized in that The ODMR spectrum acquisition module applies microwaves to the diamond to be measured, including: Controlling the microwave antenna to apply microwaves to the diamond to be measured placed at the point with the strongest microwave signal; wherein, the center frequency of the microwave antenna is set to 2.87 GHz.

7. The simple diamond NV color center four-axis measurement device according to claim 6, characterized in that, The first axial direction preliminary determination module adjusts the direction of the external magnetic field, including: Controlling the permanent magnet to adjust the direction of the external magnetic field.

8. The simple diamond NV color center four-axis measuring device according to claim 7, characterized in that, The remaining axial direction determination module includes an angle determination unit and a third and fourth axial direction determination unit: The angle determination unit is configured to determine the angle between the axial directions according to the lattice structure of the regular tetrahedron of the diamond to be measured. The third and fourth axial direction determination unit is configured to calculate the third axial direction and the fourth axial direction of the diamond NV center to be measured based on the determined first axial direction and the second axial direction of the diamond NV center to be measured and the angle between the axial directions.

9. A terminal device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements a simple method for measuring the four axial directions of a diamond NV center as described in any one of claims 1 to 4.

10. A storage medium, characterized in that, The storage medium includes a stored computer program. When the computer program runs, it controls the device where the storage medium is located to execute a simple method for measuring the four axial directions of a diamond NV center as described in any one of claims 1 to 4.

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