Cultural relic lossless dating method based on diamond nitrogen-vacancy color center quantum sensing

Abstract

The invention relates to a cultural relic lossless dating method based on diamond nitrogen-vacancy color center quantum sensing, and belongs to the technical field of cultural relic age determination and quantum sensing. The method solves the problem that destructive sampling needs to be carried out in traditional cultural relic dating technologies such as radioactive carbon dating and thermoluminescence dating, so that permanent damage is caused to cultural relics. Firstly, a sample is prepared and positioned, and a flat area rich in magnetic minerals on the surface of a cultural relic is selected; acquiring high-resolution three-dimensional shape data by using a scanning probe; a quantum probe integrated with a diamond nitrogen vacancy color center is adopted to measure surface stray magnetic field distribution in a non-contact manner through an optical detection magnetic resonance technology; based on the magnetic field data and the morphology information, equivalent thermal remanence vectors including magnetic declination, magnetic inclination and magnetization intensity in the cultural relic are calculated through a frequency domain inversion algorithm; and finally, comparing the paleomagnetic field parameter obtained by inversion with an archaeological geomagnetic long-term change reference curve, and determining a cultural relic firing age interval through least square method matching. According to the invention, zero-damage detection is realized.

Description

Technical Field

[0001] This invention belongs to the field of cultural relic dating and quantum sensing technology, and relates to a non-destructive dating method for cultural relics based on diamond nitrogen-vacancy color center quantum sensing. Background Technology

[0002] Accurate dating of cultural relics is a fundamental aspect of archaeological and historical research, crucial for revealing the evolution of human civilization. Currently, widely used dating techniques include traditional methods such as radiocarbon dating (C14) and thermoluminescence dating. However, these methods generally suffer from a major drawback: they require drilling or scraping away powder from the artifact, causing permanent and irreversible physical damage to precious and non-renewable cultural heritage. This destructive sampling method is ethically and practically unacceptable, especially when dealing with unique, rare, or structurally fragile artifacts.

[0003] Archaeomagnetic dating, as a reliable alternative, determines the age of artifacts by interpreting the paleomagnetic field information recorded during the cooling process of fired ceramics, bricks, and tiles. However, traditional archaeomagnetic measurements rely on equipment such as superconducting magnetometers, which still involve cutting or drilling samples from artifacts, failing to fundamentally overcome the constraints of destructive testing. Therefore, developing a truly non-destructive and accurate dating technique has become a crucial breakthrough urgently needed in the fields of cultural relic preservation and archaeological research.

[0004] In recent years, solid-state quantum sensing technology has made significant progress, with innovative probes such as diamond nitrogen-vacancy centers (NV centers) showing great potential. As an atomic-level magnetic field sensor, NV centers offer room-temperature operation and extremely high sensitivity (up to [missing information - likely referring to sensitivity levels]). It possesses unique advantages such as spatial resolution at the order of magnitude (magnitude) and nanometer scale, and can achieve non-invasive magnetic imaging through scanning magnetic microscopy. This provides a completely new path to solve the aforementioned long-standing technical challenges. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a non-destructive dating method for cultural relics based on diamond nitrogen-vacancy color center quantum sensing.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A non-destructive dating method for cultural relics based on diamond nitrogen-vacancy color center quantum sensing includes the following steps: S1: Sample preparation and positioning. Fix the artifact to be tested on the sample stage and select an area on the surface of the artifact that is rich in magnetic minerals and has good flatness as the area to be tested. S2: Surface topography scanning, which uses a scanning probe to acquire high-resolution three-dimensional topography data of the surface of the area to be measured; S3: Magnetic field vector imaging, which uses a probe with diamond NV color centers to perform non-contact scanning of the area under test, and measures the distribution of stray magnetic fields on the surface of the artifact by optically detected magnetic resonance (ODMR) technology. S4: Thermoremanent magnetization inversion. Based on the measured surface stray magnetic field distribution and three-dimensional morphology data, the equivalent thermomanent magnetization (TRM) vector distribution inside the artifact is calculated using a magnetic inversion algorithm, including magnetic declination, magnetic inclination, and magnetization intensity. S5: Age calibration. The direction and intensity vectors of the paleomagnetic field obtained by inversion are compared with the long-term archaeological geomagnetic variation reference curve of the known cultural relic excavation area. The firing period range of the cultural relic is determined by matching algorithm.

[0008] Furthermore, step S3 includes the following sub-steps: S31: Maintain a constant, minute distance between the probe and the surface of the artifact; S32: Irradiate the NV color center with a 532 nm wavelength laser to polarize its electron spin to state; S33: Apply a microwave field with linear frequency scanning and simultaneously monitor the fluorescence intensity of the NV color center to obtain the ODMR spectrum; S34: Resonance valley frequencies in the fitted ODMR spectrum and According to the formula Calculate the magnetic field components along the NV axis, where Electron gyromagnetic ratio; S35: By measuring the magnetic field components in different directions, the stray magnetic field vector at that point on the sample surface is calculated. .

[0009] Furthermore, step S4 employs a frequency domain inversion method, which includes the following sub-steps: S41: Distribution of the vertical component of the measured magnetic field Perform a two-dimensional Fourier transform to obtain ; S42: Utilizing transfer function relationships Solving for the equivalent magnetization in the frequency domain ,in The permeability of free space, To measure height, It is a spatial frequency vector; S43: Reconstruct the equivalent magnetization distribution on the surface of the artifact using inverse Fourier transform. .

[0010] Furthermore, in S5, the matching algorithm uses the least squares method to find the age range in which the measured paleomagnetic field vector and the long-term archaeological geomagnetic variation reference curve have the highest degree of agreement. The center value of this range is the estimated firing age of the cultural relic.

[0011] Furthermore, in step S1, when selecting the area to be measured, the area size is 20. ×20 The surface contains dark mineral spots.

[0012] Furthermore, in step S2, high-precision three-dimensional morphology data is obtained by measuring the interaction force between the NV color center probe and the sample surface using a scanning probe. x , y , z ).

[0013] Furthermore, in S31, the constant distance between the probe and the surface of the artifact is 80 nm.

[0014] Furthermore, in S33, the ODMR spectrum is obtained by monitoring the fluorescence intensity at the resonance frequency.

[0015] Furthermore, in step S43, the reconstructed equivalent magnetization distribution is used to extract magnetic declination. D and magnetic inclination I .

[0016] Furthermore, in S5, the long-term archaeological geomagnetic variation reference curve is established based on historical geomagnetic data of the area where the cultural relics were unearthed.

[0017] The beneficial effects of this invention are as follows: (1) This invention achieves completely non-destructive testing of cultural relics. The entire measurement process does not require any physical contact or chemical interaction with the surface of the cultural relic, completely avoiding the destructive operations such as drilling, cutting, or scraping samples required in traditional dating methods. This method is especially suitable for unique items, rare items, and precious cultural relics with fragile structures that do not allow sampling, truly achieving the highest requirement of zero damage in cultural relic protection.

[0018] (2) This invention possesses nanoscale high spatial resolution magnetic field imaging capability. Utilizing diamond NV color centers as atomic-level magnetic probes, its magnetic field imaging resolution is better than 50 nanometers. This advantage not only accurately acquires macroscopic thermoremanence information of cultural relics, but also clearly reveals the distribution of microscopic magnetic mineral particles inside the relics, providing unprecedented detailed information for in-depth research on the materials and craftsmanship of cultural relics.

[0019] (3) This invention possesses extremely high magnetic detection sensitivity. Its sensitivity reaches... The magnitude is sufficient to accurately detect extremely small magnetic field signals generated by the weak remanent magnetization inside the artifact. This characteristic makes the method applicable to artifacts with low magnetic mineral content as well, greatly expanding the application scope of archaeomagnetic dating technology.

[0020] (4) This invention effectively combines microscopic measurement with macroscopic dating. By accurately measuring the surface stray magnetic field using optical magnetic resonance imaging (OMRI), and then calculating the equivalent thermoremanent magnetic vector distribution inside the artifact using a magnetic inversion algorithm, the precise dating of the artifact is achieved by matching it with a long-term archaeological geomagnetic variation reference curve. This multi-step, multi-information fusion approach ensures the scientific validity and reliability of the dating results.

[0021] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is an overall flowchart of the method in the embodiments of the present invention; Figure 2 This is the NV color core energy level structure diagram; Figure 3 This is a schematic diagram of the ODMR spectral measurement principle. Figure 4 A dating map for matching the measured paleomagnetic vectors with the reference curve. Detailed Implementation

[0023] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0024] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures, and should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0025] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0026] Please see Figures 1-4 This is a quantum method for dating cultural relics.

[0027] like Figure 1 As shown, this embodiment provides a method for quantum-based dating of cultural relics, including the following steps: S1: Sample preparation and positioning. Fix the artifact to be tested on the sample stage and select an area on the surface of the artifact that is rich in magnetic minerals and has good flatness as the area to be tested. Specifically, the selection process includes: The artifact to be tested is fixed on the scanning stage without any cutting. It is then observed by scanning with an NV color center probe, selecting a point approximately 20... μm ×20 μm Areas with relatively smooth surfaces and containing dark mineral spots.

[0028] S2: Surface topography scanning, which uses a scanning probe to acquire high-resolution three-dimensional topography data of the surface of the area to be measured; Specifically, the acquisition process includes: By measuring the interaction force between the NV color center probe and the sample surface, a selected area is scanned to obtain high-precision three-dimensional topography data. x , y , z This data is used to subsequently define the distance distribution between the magnetic field source on the artifact surface and the NV color center.

[0029] S3: Magnetic field vector imaging, which uses a probe with integrated diamond nitrogen-vacancy NV color centers to perform non-contact scanning of the area under test, and measures the distribution of stray magnetic field on the surface of the artifact through optically detected magnetic resonance (ODMR) technology. Specifically, the acquisition process includes: S31: Maintain a constant probe height of approximately 80 nm above the artifact surface; S32: Irradiate the NV color center with a 532nm wavelength laser, such as... Figure 2 As shown, its electron spin is polarized to Maintaining high fluorescence intensity in the bright state prepares the fluorescence intensity for subsequent transitions to the dark state. This is to prepare for drawing ODMR spectra.

[0030] S33: The fluorescence intensity of the NV center is related to its spin state. The fluorescence intensity of the state is much higher than Therefore, by applying a microwave field with a linear frequency scan and monitoring changes in fluorescence intensity, one or two concave "valleys" can be observed at the resonance frequency, i.e., the ODMR spectrum. For example... Figure 3 The image shows an ODMR spectrum, where the frequency of the valley floor is... or ; S34: Fitting the two resonance valley frequencies in the ODMR spectrum and According to the magnetic field projection formula The magnetic field components along the NV axis are calculated, and the magnetic field distribution in the region is finally generated.

[0031] S35: By measuring the magnetic field components in different directions, the stray magnetic field vector at that point on the sample surface is calculated. .

[0032] S4: Thermal remanent magnetization inversion. Based on the measured surface stray magnetic field distribution and three-dimensional morphology data, the equivalent thermal remanent magnetization (TRM) vector distribution inside the artifact is calculated using a magnetic inversion algorithm, including magnetic declination, magnetic inclination, and magnetization intensity. Specifically, the inversion and extrapolation process includes: S41: Distribute the measured vertical component of the magnetic field. Perform a two-dimensional Fourier transform to obtain ; S42: Utilizing the transfer function relationship of the inversion operator Solving for the equivalent magnetization in the frequency domain ,in The constant height measured in S31; S43: By reconstructing the equivalent magnetization distribution of the three-dimensional surface of the artifact back to the spatial domain through inverse Fourier transform. Statistical analysis of the inverted magnetization intensity was performed to extract the dominant magnetization vector direction of the micro-region, thus obtaining the magnetic declination of the artifact. D and magnetic inclination I .

[0033] S5: Age calibration. The direction and intensity vectors of the paleomagnetic field obtained by inversion are compared with the long-term archaeological geomagnetic variation reference curve of the known cultural relic excavation area. The firing period range of the cultural relic is determined by matching algorithm.

[0034] Specifically, the confirmation process includes: S51: The magnetic declination of the paleogeothermal remanence of the artifact was measured. Magnetic inclination Calling such as Figure 4 The paleomagnetic field vector and the long-term archaeological geomagnetic variation reference curve shown are used to calculate the minimum statistical distance between the measured vector and the reference curve. The matching results show that this set of geomagnetic parameters is highly consistent with the geomagnetic characteristics in the period from 1050 to 1067 AD.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A non-destructive dating method for cultural relics based on diamond nitrogen-vacancy color center quantum sensing, characterized in that: Includes the following steps: S1: Sample preparation and positioning. Fix the artifact to be tested on the sample stage and select an area on the surface of the artifact that is rich in magnetic minerals and has good flatness as the area to be tested. S2: Surface topography scanning, which uses a scanning probe to acquire high-resolution three-dimensional topography data of the surface of the area to be measured; S3: Magnetic field vector imaging, which uses a probe with diamond NV color centers to perform non-contact scanning of the area under test, and measures the distribution of stray magnetic field on the surface of the artifact through optically detected magnetic resonance (ODMR) technology. S4: Thermoremanence inversion. Based on the measured surface stray magnetic field distribution and three-dimensional morphology data, the equivalent thermoremanence vector distribution inside the artifact is calculated using a magnetic inversion algorithm, including magnetic declination, magnetic tilt, and magnetization. S5: Age calibration. The direction and intensity vectors of the paleomagnetic field obtained by inversion are compared with the long-term archaeological geomagnetic variation reference curve of the known cultural relic excavation area. The firing period range of the cultural relic is determined by matching algorithm.

2. The non-destructive dating method for cultural relics based on diamond nitrogen-vacancy color center quantum sensing according to claim 1, characterized in that: S3 includes the following sub-steps: S31: Maintain a constant, minute distance between the probe and the surface of the artifact; S32: Irradiate the NV color center with a 532 nm wavelength laser to polarize its electron spin to state; S33: Apply a microwave field with linear frequency scanning and simultaneously monitor the fluorescence intensity of the NV color center to obtain the ODMR spectrum; S34: Resonance valley frequencies in the fitted ODMR spectrum and According to the formula Calculate the magnetic field components along the NV axis, where Electron gyromagnetic ratio; S35: By measuring the magnetic field components in different directions, the stray magnetic field vector at that point on the sample surface is calculated. .

3. The non-destructive dating method for cultural relics based on diamond nitrogen-vacancy color center quantum sensing according to claim 1, characterized in that: S4 employs a frequency domain inversion method, including the following sub-steps: S41: Distribution of the vertical component of the measured magnetic field Perform a two-dimensional Fourier transform to obtain ; S42: Utilizing transfer function relationships Solving for the equivalent magnetization in the frequency domain ,in The permeability of free space, To measure height, It is a spatial frequency vector; S43: Reconstruct the equivalent magnetization distribution on the surface of the artifact using inverse Fourier transform. .

4. The non-destructive dating method for cultural relics based on diamond nitrogen-vacancy color center quantum sensing according to claim 1, characterized in that: In S5, the matching algorithm uses the least squares method to find the age range in which the measured paleomagnetic field vector and the long-term archaeological geomagnetic variation reference curve have the highest degree of agreement. The center value of this range is the estimated value of the firing age of the cultural relic.

5. The non-destructive dating method for cultural relics based on diamond nitrogen-vacancy color center quantum sensing according to claim 1, characterized in that: In step S1, when selecting the area to be measured, the area size is 20. ×20 The surface contains dark mineral spots.

6. The non-destructive dating method for cultural relics based on diamond nitrogen-vacancy color center quantum sensing according to claim 1, characterized in that: In step S2, a scanning probe is used to measure the interaction force between the NV color center probe and the sample surface to obtain high-precision three-dimensional morphology data. x , y , z ).

7. The non-destructive dating method for cultural relics based on diamond nitrogen-vacancy color center quantum sensing according to claim 2, characterized in that: In S31, the constant distance between the probe and the surface of the artifact is 80 nm.

8. The non-destructive dating method for cultural relics based on diamond nitrogen-vacancy color center quantum sensing according to claim 2, characterized in that: In S33, the ODMR spectrum is obtained by monitoring the fluorescence intensity at the resonance frequency.

9. The non-destructive dating method for cultural relics based on diamond nitrogen-vacancy color center quantum sensing according to claim 3, characterized in that: In step S43, the reconstructed equivalent magnetization distribution is used to extract the magnetic declination. D and magnetic inclination I .

10. The non-destructive dating method for cultural relics based on diamond nitrogen-vacancy color center quantum sensing according to claim 4, characterized in that: In S5, the long-term archaeological geomagnetic variation reference curve is established based on historical geomagnetic data of the area where the cultural relics were unearthed.

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