Strong pumping bilateral resonance modulation-demodulation magnetic sensitivity enhancement method of quantum magnetic compass

Abstract

The invention discloses a strong pumping bilateral resonance modulation-demodulation magnetic sensitivity enhancement method of a quantum magnetic compass. The method comprises the following steps: constructing a quantum magnetic compass platform comprising a sensing unit and external optical and microelectronic devices; quantum state enhanced reading containing magnetic vector information is realized by using a pumping enhancement mode; a standard diamond is used, the thermal conductivity and the light transmission of the diamond are utilized, the initialization of a quantum state is realized by using near-saturation external pump light, the line width is narrowed, and the magnetic measurement sensitivity is improved; noise in the environment is filtered out in a modulation and demodulation mode, and high-robustness extraction of quantum information is achieved. By enhancing the laser pumping power, the emission speed of the solid-state quantum color center ensemble fluorescence photons is increased, the full width at half maximum of a magnetic resonance curve is compressed, and the measuring capacity of the solid-state quantum color center to a magnetic field is improved; accurate measurement of external magnetic field signals through the solid quantum color center in the diamond is realized.

Description

Technical Field

[0001] This invention belongs to the field of intelligent connected vehicle in-vehicle quantum magnetic compass technology, and particularly relates to a method for enhancing the magnetic sensitivity of a quantum magnetic compass through strong pumping bilateral resonance modulation and demodulation. Background Technology

[0002] With the rapid development of intelligent transportation technology, technologies such as autonomous driving, intelligent traffic management, and vehicle cooperative driving are receiving increasing attention from managers and users. Intelligent connected vehicles rely on high-precision positioning and navigation technologies to achieve safe and efficient autonomous driving functions. However, traditional navigation systems (such as GPS) often suffer from weak signals and insufficient positioning accuracy in complex environments (such as urban canyons, tunnels, or areas with electromagnetic interference), making it difficult to meet the stringent requirements of intelligent connected vehicles for high-precision navigation.

[0003] Quantum technology has seen rapid development in recent years. Against this backdrop, the quantum magnetic compass, as an emerging high-precision navigation technology, has gradually attracted the attention of researchers and is suitable for application in intelligent connected vehicles. It can achieve high-precision measurement of magnetic field vectors through the high sensitivity of quantum states, providing more reliable navigation support for intelligent connected vehicles. However, existing quantum magnetic compasses still face several challenges and are mainly in the laboratory stage. When applied to vehicles, it is necessary to consider how to achieve high-precision measurement and stable operation under different vehicle driving environments (such as complex electromagnetic interference, rapidly changing magnetic field environments, vehicle vibration, and variable weather conditions).

[0004] Furthermore, onboard electronic units require good environmental adaptability. Intelligent connected vehicles operate in diverse environmental scenarios, demanding that equipment maintain high-precision operation under varying conditions. However, current quantum magnetic compasses lack sufficient ability to extract effective signals in response to dynamic environmental changes, leading to reduced measurement accuracy and impacting the safe driving functions of intelligent connected vehicles.

[0005] Therefore, there is an urgent need for a quantum magnetic compass signal extraction method with environmental adaptability. By enhancing signal extraction and effective filtering, the accuracy and reliability of the system can be ensured, thus meeting the actual needs of intelligent connected vehicles for high-precision navigation in complex environments. Summary of the Invention

[0006] Objective of the Invention: The objective of this invention is to provide a method for enhancing the magnetic sensitivity of a quantum magnetic compass through strong-pumped bilateral resonant modulation and demodulation. While using conventional quantum sensing units, the method reduces linewidth to improve the sensitivity of magnetic information measurement; and through modulation and demodulation filtering methods, noise is reduced while effectively extracting the magnetic signal to be measured.

[0007] Technical solution: The present invention provides a method for enhancing the magnetic sensitivity of a quantum magnetic compass through strong-pumped bilateral resonant modulation and demodulation, comprising the following steps:

[0008] Step 1: Construct a quantum magnetic compass platform that includes the sensing unit and various external optical and microelectronic devices;

[0009] Step 2: Use pump enhancement to enhance the readout of quantum states containing magnetic vector information; use standard diamond, take advantage of its thermal conductivity and light transmittance, and use near-saturated external pump light to initialize the quantum state, narrow the linewidth, and improve the sensitivity of magnetic measurement.

[0010] Step 3: By using modulation and demodulation, noise in the environment is filtered out to achieve highly robust extraction of quantum information.

[0011] Further, step 1 specifically involves: using treated diamond as the sensitive unit in a solid-state quantum magnetic compass based on nitrogen vacancies in diamond; the processing technology involves infiltrating nitrogen into diamond material cut on the [1 1 1] crystal plane or adding nitrogen during growth, then using electron irradiation to prepare lattice vacancies inside the diamond, followed by high-temperature annealing; after preparation, diamond containing nitrogen vacancy centers cut on the [1 1 1] crystal plane is selected as the sensitive unit, pump light is added to the sensitive unit, and a parabolic prism is used to collect the fluorescence signal, while laser is used to initialize the nitrogen vacancy centers to the |0> state; a sine wave generator and a microwave modulation unit are set in the circuit, the modulation signal is a sine wave, and one allowed working condition is an amplitude of ±1V and a frequency from 1kHz to 1MHz; subsequently, the demodulation circuit is used to demodulate the fluorescence voltage signal and extract effective information.

[0012] Furthermore, by adding pump light to the sensitive unit, a laser and a convex lens are used to achieve ensemble excitation of color centers with a size of hundreds of cubic micrometers, or a laser is used to achieve excitation of color centers with a size of cubic millimeters.

[0013] Further, step 2 specifically involves the following: In the system where the NV color center interacts with the pump laser and microwave, the linear profile of the optically probed magnetic resonance (ODMR) is Lorentz-type. With increasing microwave power, spin-spin coupling leads to a decrease in the contrast and an increase in the linewidth of the magnetic resonance spectrum. The longitudinal and transverse relaxation times of the color center electron spin are represented by T1 and T2, respectively, and the corresponding attenuation rates are represented by γ2 = 1 / T2 and γ1 = 1 / T1, respectively. Under continuous laser pumping and microwave irradiation, the electron spin... The transition rate of a state is represented by Γ. p This indicates that in continuous ODMR measurements, the contrast of the magnetic resonance spectrum at each frequency point is related to the detuning amount v-v0, and the final spectrum is the Lorentz function of the microwave detuning amount v-v0, as shown in the following equation:

[0014]

[0015] In the equation, S(∞) represents the contrast when the microwave frequency is far from the resonance, C represents the contrast during the resonance period, v represents the microwave frequency acting on the nitrogen vacancy NV, v0 represents the microwave resonance frequency, Δv represents the full width at half maximum (FWHM), and the FWHM of a single nitrogen vacancy resonance peak is expressed as:

[0016]

[0017] In the formula, T2 eff and T1 eff The effective relaxation time depends on the optical pump rate 1 / T1. eff = 1 / T1+Γp and 1 / T2 eff = 1 / T2 + Γp;fr = Ω / (2π) is related to the microwave irradiation power, where Ω is NV. - The frequency of electron spin precession will broaden the resonance peak as microwave power increases; for sufficiently high microwave power, FWHM is expressed as:

[0018]

[0019]

[0020] For the NV color center ensemble, T1 is three orders of magnitude higher than T2. ​​Since the environment of each NV is different, the overall situation of NVs in diamond is considered, assuming a single color center:

[0021]

[0022] In the formula For a single NV ODMR signal, with center frequency v0, P(v0) indicates a Lorentz-type linear shape, and the ensemble average ODMR FWHM is denoted as ΔV. tot ;

[0023]

[0024] In the above equation, T2* represents the effective transverse relaxation time, assuming that the pump laser does not affect the transverse relaxation rate; therefore, γ2 eff ≈γ2, and furthermore, considering γ2 eff Significantly smaller than Δv inh Furthermore, this information cannot be obtained from the non-uniformly broadened resonance peak, so this term can be omitted. Therefore, the final equation is:

[0025]

[0026] in, The intrinsic transverse relaxation rate (FWHM) decreases with increasing pump intensity. Due to spin-spin interactions, the FWHM under low lasing pump conditions is higher than that under high lasing pump conditions. Figure 2 As shown.

[0027] Further, step 3 specifically involves: under the operating circuit of the lock-in amplifier, multiplying the fluorescence signal with the reference signal, passing it through a low-pass filter, so that the lock-in signal can reflect the resonant frequency point; converting the frequency modulation of nv into the amplitude modulation of the fluorescence voltage, adjusting θR and adding a low-pass filter to obtain a stable voltage V corresponding to the resonant frequency. X ;

[0028]

[0029] Among them, V X For demodulated signals, V I For the input fluorescence voltage signal, V R As the reference signal, ω R For the modulation frequency, θ I Let θ be the phase of the fluorescence voltage signal. R The adjustable phase of the reference signal is t, where t is time.

[0030] In typical ODMR combined with lock detection, only one frequency of microwave is applied to the NV ensemble. With the support of a lock system tracking a specific frequency, two different frequencies of microwave are applied, corresponding to transitions from ms = 0 to ms = -1 and from ms = 0 to ms = +1, respectively. At the stable power of both microwaves, it is assumed that one of the two microwaves affects a specific proportion of NVs. Without phase-locked detection, in CW-ODMR using two frequencies simultaneously, it is impossible to distinguish which frequency of microwave causes the fluorescence change, as both resonant frequencies lead to fluorescence reduction. Lock detection technology is used to generate signals with specific frequencies to determine the portion of the change originating from fluorescence. After the measurement system is configured, the modulation signal generation module outputs two different frequency modulation signals from microwave sources 1 and 2. The outputs of the two microwave sources are transmitted through an ohmic antenna near the diamond, driving the qubits to flip. The fluorescence signal obtained by the photodetector is simultaneously transmitted to the two signal input ports of the demodulation module. By adjusting the phase, the X components of the two demodulated signals are output in opposite directions, and then a differential method is used to achieve effective signal extraction.

[0031] The present invention also discloses a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method of the present invention.

[0032] The present invention also discloses a computer-readable storage medium having a computer program / instructions stored thereon, which, when executed by a processor, implements the steps of the method of the present invention.

[0033] The present invention also discloses a computer program product, including a computer program / instructions that, when executed by a processor, implement the steps of the method of the present invention.

[0034] Beneficial Effects: Compared with existing technologies, this invention has the following significant advantages: This invention enhances the fluorescence photon emission velocity of the solid-state quantum color center ensemble and compresses the full width at half maximum (FWHM) of the magnetic resonance curve by increasing the laser pump power, thereby improving the measurement capability of the solid-state quantum color center for magnetic fields. Combined with a bilateral modulation and demodulation magnetic resonance information extraction method, after achieving effective low-noise extraction of a single-channel magnetic resonance signal through single-sided magnetic resonance modulation and demodulation, the magnetic resonance information from the other side is simultaneously extracted, enabling precise measurement of external magnetic field signals through the solid-state quantum color center in diamond. Simultaneously, the zero-field splitting signal extracted by bilateral magnetic resonance measurement allows for real-time monitoring of the external temperature, reducing the impact of temperature noise on magnetic field signal measurement. This combined method helps achieve efficient and stable acquisition of magnetic field vector information. This invention uses a pump enhancement method to compress the magnetic resonance signal spectral lines in the vehicle-mounted quantum magnetic compass, achieving improved magnetic field measurement sensitivity under narrowed linewidth. The bilateral magnetic resonance modulation and demodulation method enables noise filtering and extraction of magnetic measurement information from the vehicle-mounted quantum magnetic compass. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of modulation and demodulation according to the present invention.

[0036] Figure 2 This is a schematic diagram of pump-enhanced linewidth compression.

[0037] Figure 3 A schematic diagram of a pump-enhanced bilateral resonant modulation and demodulation system.

[0038] Figure 4 This is a schematic diagram of a magnetic compass system. In the diagram, 1 is the control and signal processing unit, 2 is the photoelectric conversion module, 3 is the diamond sensing unit with abundant NV color centers, 4 is the microwave generating module, 5 is the microwave radiation structure, and 6 is the parabolic prism. Detailed Implementation

[0039] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0040] 1. In the external world, magnetic field vectors exist, which can be used for auxiliary positioning and orientation. The NV color center in diamond is a highly efficient sensing unit capable of sensing external magnetic field vectors. Unlike gaseous quantum sensing units, the crystal lattice in diamond is fixed. When the diamond position is fixed, the angle of the microscopic nitrogen-vacancy color center relative to the external reference frame is also fixed. Therefore, the color center structure in a solid medium can serve as a vector sensor for external magnetic fields. Furthermore, the NV color center's scale is on the sub-nanometer scale, naturally possessing miniaturization advantages. The energy formula for the NV color center is:

[0041]

[0042] In the formula, z is the quantum axis along the NV axis; D ≈ 2.87 GHz is the zero-field splitting parameter; γ = 28MHz / mT is the electron gyromagnetic ratio; B is the magnetic field vector; and S is the Pauli matrix of the NV electron spin.

[0043] The formula for the sensitivity of the color center is:

[0044]

[0045] This shows that the sensitivity of the NV color center is related to the received optical signal.

[0046] In systems where NV centers interact with pump lasers and microwaves, the linear profile of ODMR is typically Lorentz-type, and its spectral equation is as follows. With increasing microwave power, spin-spin coupling leads to a decrease in contrast and an increase in linewidth in the magnetic resonance spectrum. Here, the longitudinal and transverse relaxation times of the electron spins at the color centers are represented by... and The corresponding decay rates are represented by... and This indicates that under continuous laser pumping and microwave irradiation, the electron spin... The transition rate of the state is represented by Γp. In continuous ODMR measurements, the contrast and detuning of the magnetic resonance spectrum at each frequency point are... Relatedly, the final spectrum is related to the microwave detuning. The Lorentz function is shown in the following equation.

[0047]

[0048] In the equation, S(∞) represents the contrast when the microwave frequency is far from the resonance, C represents the contrast during the resonance period, and v represents the microwave frequency acting on the nitrogen vacancy (NV). This represents the resonant frequency of microwaves. The full width at half maximum (FWHM) is represented by: The full width at half maximum (FWHM) of a single nitrogen-vacancy resonance peak can be expressed as:

[0049]

[0050] In the formula, and The "effective" relaxation time depends on the optical pump rate. and . It is related to microwave irradiation power. Generally, increasing microwave power broadens the resonance peak; for sufficiently high microwave power, FWHM can be expressed as:

[0051]

[0052]

[0053] For NV color heart system Usually more Three orders of magnitude higher, while optical pumping can shorten... However, even a power output of 100 megawatts is difficult to shorten. Therefore, this invention can be based on the following assumption: Almost unaffected, and Significantly reduced. Finally, under normal operating conditions, the linewidth decreases with increasing pump power. Thereafter, since the environment of each NV is slightly different, the overall situation of NVs in diamond is considered. Single color center state:

[0054]

[0055] In the formula For a single NV ODMR signal, the center frequency is v0. The ensemble average ODMR FWHM is denoted as... , obtained from typical ODMR experiments.

[0056]

[0057] In the above equation, , The linear shape is Lorentz-type. Finally, the assumption that the pump laser does not affect the transverse relaxation rate is given; therefore, ≈ Furthermore, considering Significantly smaller than Furthermore, this information is difficult to obtain from non-uniformly broadened resonance peaks, so this term can be omitted. Therefore, the final equation is:

[0058]

[0059] As the pump light intensity increases, the bandwidth of the resonance peak decreases. Due to the strong spin-spin interaction, the full width at half maximum (FWHM) under low laser pump conditions is higher than that under high laser pump conditions.

[0060] 2. Overall Structure of the Magnetic Compass. The overall structure uses a diamond containing NV centers as the sensing element, externally equipped with a green LED light, an RF microwave antenna, a parabolic prism, and a balanced photodetector. In this design, the LED light pumps the NV centers to their ground state with electron spin of 0. The RF microwave antenna provides the microwave signal that flips the NV centers, with the required microwave frequency and power provided by a miniaturized microwave source within the device. Since the ground state energy level of the NV centers is degenerate in the absence of a magnetic field, an initial magnetic field of approximately 1 mT is applied using an external permanent magnet to remove the degeneracy. Due to the extremely high refractive index of the diamond NV centers, a parabolic prism is used to collect the fluorescence signal to improve fluorescence collection efficiency. Furthermore, a balanced photodetector is used to extract the effective fluorescence change signal to reduce interference from fluorescence substrate noise.

[0061] 3. High Laser Pump Power Used in Magnetic Compass. In quantum sensing of NV centers in diamond, the laser pump power affects the polarization rate and fluorescence intensity of the NV centers, and this parameter also affects the efficiency of microwave-induced NV center reversal. In this design, diamond samples containing 3 ppm of NV centers were used, with a laser pump power of 500 mW and a modular microwave source output power of 1 W. Experimental tests showed that significant photodetector magnetic resonance peaks could be observed under these parameters. When the laser power and microwave source power are not coordinated, the fluorescence intensity will not change with the frequency sweep of the NV microwave source. The fluorescence formula for the NV centers is as follows, showing a linear relationship between fluorescence intensity and the power of the input pump light between threshold values. Diamond is a very good transparent material, capable of transmitting light in the visible region with an efficiency of over 95%. However, when the pump laser intensity is significantly high, the temperature of the diamond increases, affecting the stability of magnetic measurements. Shifting the wavelength of fluorescence, the light output energy of one pump-radiation cycle is ~1.7804 eV; while the input energy of the excitation photon is 2.3305 eV. It can be inferred that ~0.55 eV is transferred to the non-radiative process. A cubic micrometer diamond with 2 ppm NV defects outputs 2 W of heat after one pump-radiation cycle. Diamond is a good thermal conductor with a thermal conductivity of 2000 W·m. −1 ⋅K −1 It can easily dissipate the heat generated by light pumping.

[0062]

[0063] 4. Modulation and demodulation technology used in the NV color center of the magnetic compass. The signal of the NV color center changing with the microwave frequency is a curve with a shape similar to a Lorentz or Gaussian line. It is difficult to accurately extract the resonant frequency position from this curve. Modulation and demodulation technology is used, using an onboard signal source to output a sinusoidal signal to frequency modulate the frequency signal of the onboard microwave source. Since the change in the microwave source frequency will drive the change in the fluorescence signal, the modulated signal is multiplied by the acquired fluorescence voltage signal in the device, and then the high-frequency signal is filtered out to obtain a significant DC signal.

[0064] Lock-in detection can extract weak signals of a specific frequency from a noisy background. ODMR detection is often affected by noise, such as laser power jitter and electronic noise from photodetectors. Applying lock-in detection in ODMR detection can obtain signals with low noise floor. The combination of ODMR and lock-in detection often requires a reference oscillation signal in both the microwave source and the lock-in amplifier. The reference signal in the microwave source, through a set demodulation depth and modulation frequency, causes the output microwave frequency to oscillate around a certain point. Within the allowable range of the longitude relaxation time of the NV defect, the generated fluorescence oscillates within the frequency of the modulation signal with a large amplitude. Under the working circuit of the lock-in amplifier, the fluorescence signal is multiplied by the reference signal, and after passing through a low-pass filter, the lock-in signal can accurately reflect the resonant frequency point with ultra-low noise. This invention temporarily rationalizes the frequency modulation of NV as the amplitude modulation of the fluorescence voltage, adjusting... After adding a low-pass filter, a stable voltage corresponding to the resonant frequency is obtained. .

[0065]

[0066] in, For demodulated signals, For input fluorescence voltage signal, For reference signal, For modulation frequency, The phase of the fluorescence voltage signal. The adjustable phase of the reference signal.

[0067] 5. Bilateral modulation and demodulation technology used in the NV color center of the magnetic compass. Since the NV color center, after degeneracy under the influence of a magnetic field, splits into high and low energy levels, the intermediate value of these two frequencies is related to the temperature of the NV color center. Furthermore, because the NV color center is also a good temperature-sensitive unit, changes in external temperature can introduce errors into the measurement of the magnetic field vector. Therefore, bilateral modulation and demodulation technology can be used to simultaneously detect the reversal of the ground state quantities of both the high and low energy levels, reducing the impact of temperature drift on the detection of the NV color center's magnetic field.

[0068] In typical ODMR combined with lock-in detection, only one frequency of microwave is applied to the NV ensemble. Supported by a lock-in system tracking a specific frequency, this invention applies two different microwave frequencies, corresponding to transitions from |ms = 0> to |ms = -1> and from |ms = 0> to |ms = +1>, respectively. At stable power for both microwaves, it can be assumed that one of the two microwaves affects a specific proportion of NVs. Without phase-locked detection, when using both frequencies simultaneously in CWODMR, it is impossible to distinguish which microwave frequency causes the fluorescence change because both resonant frequencies result in a reduction in fluorescence. Using lock-in detection to generate a signal with a specific frequency allows identification of the portion of the change originating from fluorescence. The measurement system composition is as follows... Figure 4 As shown, two modulation signals of different frequencies modulate the outputs of two microwave sources, which are transmitted through an ohmic antenna near the diamond, driving the qubits to flip. A fluorescence signal obtained by a photodetector is simultaneously transmitted to the two signal input ports of a lock-in amplifier. By adjusting the phase, the X components of the two demodulated signals are output in opposite directions.

Claims

1. A method for enhancing the magnetic sensitivity of a quantum magnetic compass through strong-pumped bilateral resonant modulation and demodulation, characterized in that, Includes the following steps: Step 1: Construct a quantum magnetic compass platform that includes the sensing unit and various external optical and microelectronic devices; Step 2: Use pump enhancement to enhance the readout of quantum states containing magnetic vector information; use standard diamond, take advantage of its thermal conductivity and light transmittance, and use near-saturated external pump light to initialize the quantum state, narrow the linewidth, and improve the sensitivity of magnetic measurement. Step 3: By using modulation and demodulation, noise in the environment is filtered out to achieve highly robust extraction of quantum information.

2. The method for enhancing the magnetic sensitivity of a quantum magnetic compass by strong pumping bilateral resonant modulation and demodulation according to claim 1, characterized in that, Step 1 is as follows: The solid-state quantum magnetic compass based on nitrogen vacancies in diamond uses processed diamond as the sensitive unit; the processing technology is to infiltrate nitrogen element into diamond material cut with [1 1 1] crystal plane or add nitrogen element during growth, and then use electron irradiation to prepare the lattice vacancies inside the diamond, and then use high temperature annealing; after the preparation is completed, diamond containing nitrogen vacancy color centers cut with [1 1 1] is selected as the sensitive unit, pump light is added to the sensitive unit, and a parabolic prism is used to collect the fluorescence signal. Laser is used to initialize the nitrogen vacancy color centers to the |0> state; a sine wave generator and a microwave modulation unit are set in the circuit. The modulation signal is a sine wave, and the working conditions are an amplitude of ±1V and a frequency from 1kHz to 1MHz; subsequently, the demodulation circuit is used to demodulate the fluorescence voltage signal and extract effective information.

3. The method for enhancing the magnetic sensitivity of a quantum magnetic compass by strong pumping bilateral resonant modulation and demodulation according to claim 2, characterized in that, The process involves adding pump light to the sensitive unit and using a laser with a convex lens to achieve ensemble excitation of color centers with a size of 100 cubic micrometers, or using a laser to achieve excitation of color centers with a size of 1 cubic millimeter.

4. The method for enhancing the magnetic sensitivity of a quantum magnetic compass with strong pumping bilateral resonant modulation and demodulation according to claim 1, characterized in that, Step 2 specifically involves the following: In the system where the NV color center interacts with the pump laser and microwave, the linear profile of the optically probed magnetic resonance (ODMR) spectrum is Lorentz-type. With increasing microwave power, spin-spin coupling leads to a decrease in the contrast and an increase in the linewidth of the magnetic resonance spectrum. The longitudinal and transverse relaxation times of the electron spin at the color center are represented by T1 and T2, respectively, and the corresponding attenuation rates are represented by γ2 = 1 / T2 and γ1 = 1 / T1, respectively. Under continuous laser pumping and microwave irradiation, the electron spin... The transition rate of a state is represented by Γ. p This indicates that in continuous ODMR measurements, the contrast of the magnetic resonance spectrum at each frequency point is related to the detuning amount v-v0, and the final spectrum is the Lorentz function of the microwave detuning amount v-v0, as shown in the following equation: ； In the equation, S(∞) represents the contrast when the microwave frequency is far from the resonance, C represents the contrast during the resonance period, v represents the microwave frequency acting on the nitrogen vacancy NV, v0 represents the microwave resonance frequency, Δv represents the full width at half maximum (FWHM), and the FWHM of a single nitrogen vacancy resonance peak is expressed as: ； In the formula, T2 eff and T1 eff The effective relaxation time depends on the optical pump rate 1 / T1. eff = 1 / T1+Γp and 1 / T2 eff = 1 / T2 + Γp;fr = Ω / (2π) is related to microwave irradiation power, where Ω is NV. - The frequency of electron spin precession will broaden the resonance peak as microwave power increases; for sufficiently high microwave power, FWHM is expressed as: ； ； For the NV color center ensemble, T1 is three orders of magnitude higher than T2. ​​Since the environment of each NV is different, the overall situation of NVs in diamond is considered, assuming a single color center: ； In the formula For a single NV ODMR signal, with center frequency v0, P(v0) indicates a Lorentz-type linear shape, and the ensemble average ODMR FWHM is denoted as ΔV. tot ; ； In the above equation, , To determine the effective transverse relaxation time, the assumption is made that the pump laser does not affect the transverse relaxation rate; therefore, γ2 eff ≈γ2, and furthermore, based on γ2 eff Significantly smaller than Δv inh Furthermore, this information cannot be obtained from the non-uniformly broadened resonance peak, so this term can be omitted. Therefore, the final equation is: ； in, The intrinsic transverse relaxation rate is denoted as FWHM. As the pump intensity increases, the bandwidth of the resonance peak decreases. Due to the spin-spin interaction, FWHM under low laser pump conditions is higher than that under high laser pump conditions.

5. The method for enhancing the magnetic sensitivity of a quantum magnetic compass by strong pumping bilateral resonant modulation and demodulation according to claim 1, characterized in that, Step 3 specifically involves: In the operating circuit of the lock-in amplifier, multiplying the fluorescence signal with the reference signal, passing it through a low-pass filter, and ensuring the lock-in signal reflects the resonant frequency; converting the frequency modulation of nv into amplitude modulation of the fluorescence voltage, adjusting θR, and adding a low-pass filter to obtain a stable voltage V corresponding to the resonant frequency. X ; ； Among them, V X For demodulated signals, V I For the input fluorescence voltage signal, V R As the reference signal, ω R For the modulation frequency, θ I Let θ be the phase of the fluorescence voltage signal. R The adjustable phase of the reference signal is t, where t is time. In typical ODMR combined with lock detection, only one frequency of microwave is applied to the NV color center ensemble. With the support of a lock system tracking a specific frequency, two different frequencies of microwave are applied, corresponding to transitions from ms = 0 to ms = -1 and from ms = 0 to ms = +1, respectively. At the stable power of both microwaves, it is assumed that one of the two microwaves affects a specific proportion of NVs. Without phase-locked detection, in CW-ODMR using two frequencies simultaneously, it is impossible to distinguish which frequency of microwave causes the fluorescence change, as both resonant frequencies lead to fluorescence reduction. Lock detection technology is used to generate signals with specific frequencies to determine the portion of the change originating from fluorescence. After the measurement system is configured, the modulation signal generation module outputs two different frequency modulation signals from microwave sources 1 and 2. The outputs of the two microwave sources are transmitted through an ohmic antenna near the diamond, driving the qubits to flip. The fluorescence signal obtained by the photodetector is simultaneously transmitted to the two signal input ports of the demodulation module. By adjusting the phase, the X components of the two demodulated signals are output in opposite directions, and then a differential method is used to achieve effective signal extraction.

6. A computer device comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method of claim 1.

7. A computer-readable storage medium having a computer program / instructions stored thereon, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method of claim 1.

8. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method of claim 1.

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