Temperature control system and method based on NV color center

Abstract

The invention relates to the technical field of temperature control, in particular to a temperature control system and method based on an NV color center, and the system comprises a diamond NV color center temperature sensing module which is used for sensing the temperature change of a target area in real time and generating a corresponding fluorescence signal; the dual-channel demodulation and signal processing module is connected with the diamond NV color center temperature sensing module and is used for extracting an actual temperature value from the fluorescence signal; the PID temperature control module is connected with the dual-channel demodulation and signal processing module and is used for generating a control signal according to the deviation between the actual temperature value and the target temperature value; and the adjustment execution module is connected with the PID temperature control module and is used for adjusting the temperature of the target area according to the control signal. The high-stability temperature control system has the beneficial effects that diamond NV color center quantum sensing, two-channel demodulation and PID closed-loop control technologies are fused, and high-stability temperature control of milliKelvin-level precision and microsecond-level response under the micro-nano scale is realized.

Description

Technical Field

[0001] This invention relates to the field of temperature control technology, and in particular to a temperature control system and method based on NV color centers. Background Technology

[0002] In modern industry and scientific research, precise temperature control has become a core requirement in many high-tech fields such as chip manufacturing, quantum computing, and biomedicine.

[0003] However, existing temperature control schemes suffer from the following significant drawbacks: traditional thermistors, thermocouples, and other sensors are not only bulky but also possess considerable thermal inertia, making it difficult to achieve rapid temperature response at micro-nano scale spatial resolution. Furthermore, they are susceptible to interference in extreme environments such as strong electromagnetic fields. Although novel quantum sensing materials, represented by diamond nitrogen-vacancy (NV) centers, have attracted widespread attention in recent years due to their ultra-high sensitivity to physical quantities such as temperature and magnetic fields, current technologies generally focus on the sensing principle itself. How to demodulate the weak fluorescence signal of NV centers with a high signal-to-noise ratio to obtain stable and accurate temperature feedback, and use this to drive actuators to achieve millisecond or even microsecond-level closed-loop control, remains a pressing technical challenge. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a temperature control system based on NV color centers, including a diamond NV color center temperature sensing module, which is used to sense the temperature change of the target area in real time and generate a corresponding fluorescence signal. A dual-channel demodulation and signal processing module is connected to the diamond NV color center temperature sensing module to extract the actual temperature value from the fluorescence signal; The PID temperature control module, connected to the dual-channel demodulation and signal processing module, is used to generate a control signal based on the deviation between the actual temperature value and the target temperature value. The adjustment execution module is connected to the PID temperature control module and is used to adjust the temperature of the target area according to the control signal; The actual temperature value is continuously fed back to the PID temperature control module to form a closed-loop control.

[0005] As a preferred embodiment of the temperature control system based on NV color centers of the present invention, the diamond NV color center temperature sensing module includes, Diamond NV color center probe; The laser excitation unit is used to emit laser light to excite the diamond NV color center probe to produce fluorescence. A fluorescence collection and filtering unit is used to collect fluorescence and filter out the excitation laser. A photodetector is used to convert filtered fluorescence signals into electrical signals.

[0006] As a preferred embodiment of the temperature control system based on NV color centers of the present invention, the dual-channel demodulation and signal processing module includes, The microwave generation and modulation unit is used to generate modulated microwaves and couple them to the diamond NV center probe to control the spin state of the NV center. A dual-channel lock-in amplifier is used to synchronously demodulate electrical signals with reference to the modulation frequency of the modulated microwave. The data acquisition and digitization unit is used to perform analog-to-digital conversion on the analog demodulated signal output from the dual-channel lock-in amplifier; The digital signal processing unit is used to process the digitized signal and calculate the actual temperature value based on the pre-calibrated temperature-frequency relationship.

[0007] As a preferred embodiment of the temperature control system based on NV color centers of the present invention, the PID temperature control module includes, The error calculation unit is used to calculate the deviation between the actual temperature value and the target temperature value. A PID controller is used to generate a control output based on the deviation using proportional, integral, and derivative algorithms. The control signal output unit is used to convert the control output quantity into a signal that can be recognized by the regulation execution module.

[0008] As a preferred embodiment of the temperature control system based on NV color centers of the present invention, the adjustment execution module includes, A heating unit is used to heat the target area; A refrigeration unit is used to cool the target area; The drive and power regulation unit is used to adjust the power output of the heating or cooling unit according to the control signal.

[0009] As a preferred embodiment of the temperature control system based on NV color centers of the present invention, wherein: the diamond NV color center probe is made of diamond containing a high concentration and uniformly distributed NV color centers inside; Diamond NV color center probes are fabricated to the nanoscale or microscale.

[0010] As a preferred embodiment of the temperature control system based on NV color centers of the present invention, the laser wavelength emitted by the laser excitation unit is 532nm or 520nm.

[0011] Secondly, the present invention provides a temperature control method based on NV color centers, comprising: sensing the temperature change of the target area in real time through a diamond NV color center temperature sensing module and generating a corresponding fluorescence signal; The fluorescence signal is demodulated and processed by a dual-channel demodulation and signal processing module to extract the actual temperature value. The PID temperature control module compares the actual temperature value with the target temperature value and generates a control signal based on the deviation. The temperature of the target area is adjusted by regulating the execution module according to the control signal; The extracted actual temperature value is continuously fed back to the PID temperature control module to form a closed-loop control.

[0012] As a preferred embodiment of the temperature control method based on NV color centers of the present invention, wherein: generating a control signal includes, Using the PID algorithm, the control output is calculated based on the temperature deviation, and the control output is converted into a pulse width modulation signal or an analog voltage / current signal.

[0013] As a preferred embodiment of the temperature control method based on NV color centers of the present invention, the extraction of actual temperature values ​​includes, By utilizing microwave modulation and dual-channel phase-locked demodulation technology, the signals of two resonance peaks or the I / Q components of the signal in the optically detected magnetic resonance spectrum can be processed simultaneously. The common-mode noise is suppressed and the change in the zero-field splitting parameter D is calculated. The actual temperature value is then retrieved through a pre-calibrated temperature-frequency relationship.

[0014] Compared with existing technologies, the beneficial effects of this invention are as follows: By integrating the high sensitivity of diamond NV color center quantum sensing with dual-channel demodulation technology, it breaks through the performance limits of traditional temperature sensors at the micro-nano scale, achieving precise local temperature sensing with milliKelvin-level accuracy and microsecond-level response speed; thanks to the synergistic optimization of diamond's ultra-high thermal conductivity and PID closed-loop control, the system can not only achieve rapid dynamic temperature stabilization of micron / nano-scale target areas in application scenarios such as quantum chips and micro-nano electronic devices, but also effectively suppress common-mode noise such as laser power fluctuations and electromagnetic interference through the dual-channel structure, significantly improving robustness. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a system block diagram of a temperature control system based on NV color centers.

[0017] Figure 2 This is a schematic diagram of temperature measurement.

[0018] Figure 3 This is a schematic diagram of temperature closed-loop control.

[0019] Figure 4 This is a schematic diagram showing the energy level of the NV color center in diamond as a function of temperature.

[0020] Figure 5 This is the photodetector magnetic resonance spectrum when the temperature is increased from room temperature to 38.5℃.

[0021] Figure 6 This is a flowchart illustrating the temperature control method based on NV color centers. Detailed Implementation

[0022] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0023] Example 1, referring to Figure 1 This is the first embodiment of the present invention, which provides a temperature control system based on NV color centers, comprising: Diamond NV color center temperature sensing module 1 is used to sense the temperature change of the target area in real time and generate the corresponding fluorescence signal; The dual-channel demodulation and signal processing module 2 is connected to the diamond NV color center temperature sensing module 1 and is used to extract the actual temperature value from the fluorescence signal. The PID temperature control module 3 is connected to the dual-channel demodulation and signal processing module 2 and is used to generate a control signal based on the deviation between the actual temperature value and the target temperature value. The adjustment execution module 4 is connected to the PID temperature control module 3 and is used to adjust the temperature of the target area according to the control signal. The actual temperature value is continuously fed back to the PID temperature control module 3 to form a closed-loop control.

[0024] It should be noted that the qubits in quantum computing chips are extremely sensitive to fluctuations in ambient temperature. Temperature changes at the milliKelvin level can cause quantum decoherence, distorting the calculation results. Traditional temperature sensors, due to their large thermal inertia and spatial resolution of only millimeters, cannot accurately capture transient temperature gradients in the micro-nano scale region of the chip surface. At the same time, electromagnetic interference and laser power drift in the experimental environment further aggravate measurement noise, making it difficult to achieve fast and accurate closed-loop temperature control.

[0025] Therefore, to address the high-precision temperature control requirements of quantum computing chips at the micro-nano scale, this system utilizes the high thermal conductivity and quantum sensitivity of the diamond NV color center probe 11 to improve the temperature response speed to the microsecond level; it employs dual-channel demodulation technology to suppress common-mode noise, ensuring a high signal-to-noise ratio and stability of the temperature measurement; and it uses PID closed-loop control combined with PWM fast power regulation to offset ambient temperature disturbances in real time, achieving millisecond-level precise temperature stability of the target area of ​​the quantum chip, thereby ensuring the coherence of the qubits and extending their decoherence time.

[0026] Example 2, refer to Figures 1-5 As an embodiment of the present invention, a temperature control system based on NV color centers is provided based on the above embodiment.

[0027] Diamond NV color center temperature sensing module 1 is used to sense the temperature change of the target area in real time and generate the corresponding fluorescence signal; Understandably, the target region refers to the qubits on the quantum chip that require precise temperature control and their surrounding micro-nano scale environment.

[0028] Furthermore, the diamond NV color center temperature sensing module 1 includes, Diamond NV color center probe 11; Preferably, the diamond NV color center probe 11 is made of diamond containing a high concentration and uniform distribution of NV color centers, and the diamond NV color center probe 11 is prepared in the nanometer or micrometer scale.

[0029] It should be noted that the diamond NV center probe 11 is used to utilize the quantum properties of the NV centers themselves to directly convert the physical quantity of temperature into changes in the internal electronic energy levels (zero-field splitting parameter D value). Specifically, high-quality single-crystal diamond is selected, and through processes such as ion implantation and high-temperature annealing, a high concentration and uniform distribution of nitrogen-vacancy (NV) centers are formed inside. Combined with the high thermal conductivity of diamond (approximately 2000 W / (m·K)), this ensures that the NV centers can quickly respond to temperature changes in the target area. It is important to emphasize that this probe can not only sense micro-area temperature but also respond rapidly to temperature changes.

[0030] Ideally, fabrication at the nanoscale or microscale makes it possible to directly measure the temperature gradient near a single qubit, something that is absolutely impossible with traditional bulk sensors.

[0031] The laser excitation unit 12 is used to emit laser light to excite the diamond NV color center probe 11 to generate fluorescence; Preferably, the laser wavelength emitted by the laser excitation unit 12 is 532nm or 520nm. This preferred wavelength range is the optimal choice for exciting NV color centers to generate fluorescence (its fluorescence wavelength is in the red band of 600-850nm), which can achieve a high fluorescence yield.

[0032] It should be noted that the laser excitation unit 12 uses a high-stability, low-noise solid-state laser, which outputs a green laser with a wavelength of 532nm or 520nm. Furthermore, the laser power should be precisely controllable to avoid measurement errors introduced by the laser heating effect. An acousto-optic modulator (AOM) or an electro-optic modulator (EOM) can be used to quickly modulate and stabilize the laser power. Specifically, during use, the laser beam passes through an optical fiber coupler or a free-space optical system, and after beam expansion, collimation, and focusing, it is precisely focused onto the target (measurement) area of ​​the diamond NV color center probe 11.

[0033] The fluorescence collection and filtering unit 13 is used to collect fluorescence and filter out the excitation laser. Understandably, the purpose of setting up the fluorescence collection and filtering unit 13 is to efficiently collect weak NV color center fluorescence under extremely strong excitation laser background noise and to filter out scattered light from the excitation laser to the maximum extent. Specifically, this unit includes a high numerical aperture (NA) microscope objective (e.g., NA≥0.8), a dichroic mirror, and a long-pass filter (e.g., a long-pass filter with a cutoff wavelength of 647 nm).

[0034] It should be noted that a high numerical aperture (NA) microscope objective is used to ensure that as many fluorescence photons as possible are collected, thereby enhancing signal intensity. Simultaneously, the dichroic mirror and long-pass filter constitute a highly efficient optical filtering system, allowing only the red fluorescence at the NV color center to pass through while resolutely blocking the green excitation laser. Specifically, during operation, the high numerical aperture (NA) microscope objective collects as many fluorescence photons as possible, and then the highly efficient optical filtering system consisting of the dichroic mirror and long-pass filter filters out the excitation laser, allowing only the red fluorescence at the NV color center to pass through.

[0035] The photodetector 14 is used to convert the filtered fluorescence signal into an electrical signal.

[0036] It should be noted that the photodetector 14 uses a high-sensitivity avalanche photodiode (APD) or photomultiplier tube (PMT) (because the fluorescence signal emitted by the NV color center is extremely weak, and such a high-sensitivity detector with an internal gain mechanism is required for effective detection) to convert the collected fluorescence signal into an electrical signal. Furthermore, to support dual-channel demodulation, a beam splitter can be used to split the fluorescence signal into two paths, which are then sent to two independent photodetectors 14, or a photodetector 14 with dual output function can be used to simultaneously acquire the two resonance peak signals or I / Q component signals of the ODMR spectrum.

[0037] Preferably, the diamond NV color center temperature sensing module 1 in this system achieves spatial resolution and rapid response through a micro-nano diamond probe, then effectively excites the signal with a specific wavelength laser, purifies the signal through a precision optical system, and finally completes photoelectric conversion with a high-sensitivity detector. This series of steps are interconnected and together ensure that a high-fidelity, high signal-to-noise ratio, fast-response temperature signal originating from the micro-nano scale can be provided to the subsequent system, thus making it possible to ultimately achieve ultra-high precision temperature closed-loop control.

[0038] The dual-channel demodulation and signal processing module 2 is connected to the diamond NV color center temperature sensing module 1 and is used to extract the actual temperature value from the fluorescence signal. Understandably, the purpose of setting up the dual-channel demodulation and signal processing module 2 is to accurately extract the quantum state change information directly related to temperature from the noisy and weak fluorescent electrical signal, and convert it into a high-precision digital temperature value.

[0039] Furthermore, the dual-channel demodulation and signal processing module 2 includes, The microwave generation and modulation unit 21 is used to generate modulated microwaves and couple them to the diamond NV center probe 11 to control the spin state of the NV center. It should be noted that the function of the microwave generation and modulation unit 21 is to precisely manipulate the electron spin state of the NV color center through a microwave field, providing a physical intervention method for temperature measurement based on optically detected magnetic resonance (ODMR). Specifically, this unit uses a microwave signal generator to generate a frequency-tunable microwave signal (e.g., around 2.8 GHz), which is connected to a microwave antenna (such as a loop antenna or microstrip line) via an RF coaxial cable and coupled to the probe area. It is important to emphasize that the microwave signal needs to be frequency-modulated (FM) or amplitude-modulated (AM), and its modulation frequency must be synchronized with the reference frequency of the lock-in amplifier. This is to cooperate with subsequent lock-in demodulation technology, thereby converting the physical change of temperature into a spectral change that can be processed by electrical signals.

[0040] The dual-channel lock-in amplifier 22 is used to synchronously demodulate electrical signals with reference to the modulation frequency of the modulated microwave. It should be noted that the dual-channel lock-in amplifier 22 is the core component of this module for achieving high signal-to-noise ratio signal extraction. Specifically, the dual-channel lock-in amplifier should have two independent input channels, capable of simultaneously processing two signal components of different frequencies or phases. For example, in ODMR temperature measurement, it can simultaneously track two temperature-shifting resonance peaks (corresponding to m) in the ODMR spectrum of the NV color center. s =0 to m s =±1 transition), or obtain the I (in-phase) and Q (quadrature) components of the signal through quadrature demodulation.

[0041] like Figure 4 As shown in the figure, this diagram illustrates the electron spin ground state (m) of the diamond NV color center under zero magnetic field. s =0) and excited state (m s The energy level splitting (zero-field splitting, ZFS) between m and ±1 is denoted by the parameter Dgs. As the ambient temperature increases, the thermal expansion of the diamond lattice leads to changes in the internal stress of the NV centers, thus affecting the zero-field splitting parameter Dgs. Specifically, m... s =0 energy level and m s The spacing between the ±1 energy levels decreases linearly with increasing temperature, meaning the Dgs value decreases as temperature rises. This reduction in energy level spacing manifests as a blue shift (movement towards lower frequencies) of the resonance frequency in optically detected magnetic resonance (ODMR) spectra. β·ΔT in the figure represents the energy level shift caused by the temperature change ΔT, visually illustrating the temperature sensitivity of the NV color center energy levels and forming the physical basis for temperature sensing.

[0042] Preferably, this dual-channel differential measurement method can effectively suppress common-mode noise such as laser power fluctuations and microwave power drift, improving the system's signal-to-noise ratio and measurement stability by several orders of magnitude.

[0043] The data acquisition and digitization unit 23 is used to perform analog-to-digital conversion on the analog demodulated signal output from the dual-channel lock-in amplifier; Understandably, the purpose of this unit is to convert analog voltage signals into digital signals for subsequent digital processing. Specifically, this unit uses a high-precision analog-to-digital converter (ADC), such as a 16-bit or 24-bit high-resolution ADC chip, to digitally sample the analog demodulated signal (usually a DC voltage signal) output from the lock-in amplifier, ensuring the accuracy and anti-interference capability of the temperature measurement.

[0044] The digital signal processing unit 24 is used to process the digitized signal and calculate the actual temperature value based on the pre-calibrated temperature-frequency relationship.

[0045] It should be noted that the digital signal processing unit 24 is responsible for the final temperature calculation. Specifically, this unit is implemented by a high-performance digital signal processor (DSP) or field-programmable gate array (FPGA), which performs digital filtering, signal averaging, baseline correction, and other processing on the digitized dual-channel signal to further improve measurement accuracy and stability. Based on the dual-channel demodulation results and combined with the pre-calibrated correspondence between the D value and temperature, the current actual temperature value is accurately calculated and transmitted to the PID temperature control module 3.

[0046] Reference Figure 5 As shown in the figure, this graph displays the ODMR spectra of diamond NV centers at different temperatures (25.0℃ and 38.5℃). ODMR spectra are obtained by scanning microwave frequencies and monitoring changes in the fluorescence intensity of the NV centers. When the microwave frequency matches the electron spin resonance frequency of the NV centers, the fluorescence intensity decreases, forming a resonance peak. As can be seen from the figure, as the temperature increases from 25.0℃ to 38.5℃, both resonance peaks in the ODMR spectrum shift towards lower frequencies (i.e., a blue shift occurs). This resonance frequency shift is linearly related to temperature changes; by accurately measuring the resonance frequency shift, the current actual temperature can be deduced. The ΔV marked in the figure represents the change in fluorescence signal intensity due to temperature changes at a fixed microwave frequency, providing a direct measurement basis for real-time temperature control based on fluorescence signal changes. Through detailed analysis of the ODMR spectrum, combined with a pre-calibrated temperature-frequency relationship curve, high-precision temperature measurement can be achieved.

[0047] Preferably, this unit accurately calculates the change in the zero-field splitting parameter D based on the dual-channel demodulation results, and then combines it with the temperature-D value relationship curve (i.e., temperature-frequency relationship) calibrated in advance through experiments to finally deduce the actual temperature value of the target area.

[0048] In one alternative implementation, the actual temperature value can be calculated based on the pre-calibrated temperature-frequency relationship using the dual-resonance peak center frequency difference calibration method. That is, a dual-channel lock-in amplifier synchronously locks two resonant peaks and outputs their respective center frequencies f1 and f2 in real time, and calculates Δf = f2 - f1. The temperature can then be directly converted by looking up a table or using a linear formula.

[0049] In another alternative implementation, the actual temperature value can be calculated based on the pre-calibrated temperature-frequency relationship using a fast inversion method using the ratio of fluorescence intensity at two frequencies. This involves outputting a dual-frequency composite microwave signal (f1 and f2 superimposed) through a microwave generator, synchronously demodulating the signal with each channel lock-in amplifier using its respective frequency as a reference, and outputting two DC signals representing I1 and I2. The DSP then calculates the ratio R in real time and looks up the temperature value in a table.

[0050] Preferably, the dual-channel demodulation and signal processing module 2 in this system, from precisely manipulating the spin state of the NV color center through microwave, to using dual-channel phase-locked loop technology to suppress various common-mode noises, and then through high-precision digital acquisition, finally completes temperature calculation through digital signal processing, this series of processes are closely linked and together constitute a complete quantum signal extraction and processing scheme, providing a stable, reliable and high-precision temperature feedback signal for the subsequent PID control module.

[0051] The PID temperature control module 3 is connected to the dual-channel demodulation and signal processing module 2. It is used to generate a control signal based on the deviation between the actual temperature value and the target temperature value. The actual temperature value is continuously fed back to the PID temperature control module 3 to form a closed-loop control.

[0052] Understandably, the purpose of setting up the PID temperature control module 3 is to establish a precise temperature regulation decision mechanism, convert high-precision temperature measurement values ​​into effective control commands, and form a closed-loop control system through continuous temperature feedback, thereby achieving dynamic and stable control of the target temperature.

[0053] Furthermore, the PID temperature control module 3 includes, Error calculation unit 31 is used to calculate the deviation between the actual temperature value and the target temperature value; It should be noted that the error calculation unit 31 is responsible for receiving the actual temperature measurement value from the digital signal processing unit 24 in real time, and comparing it with the target temperature value set by the system control module (which can be set separately according to actual needs, and is not limited here) to calculate the instantaneous temperature deviation (the formula is: Error = set temperature - actual temperature).

[0054] PID controller 32 is used to generate control output based on deviation using proportional, integral, and derivative algorithms; It should be noted that the PID controller 32 in this module is based on the temperature deviation output by the error calculation unit 31, and uses proportional (P), integral (I), and derivative (D) algorithms to perform comprehensive calculations to generate the optimal control output. Specifically, the proportional action provides a control force proportional to the current deviation, achieving a fast response; the integral action is used to eliminate long-term steady-state error, ensuring that the temperature eventually stabilizes precisely at the set value; and the derivative action predicts the temperature change trend, effectively suppressing overshoot and oscillation.

[0055] In one optional implementation, the control output generated using proportional, integral, and derivative algorithms can be achieved through adaptive fuzzy PID control based on the nonlinear response of the NV color center. This involves introducing a fuzzy inference mechanism, using the temperature deviation e(t) and the rate of change of deviation de(t) / dt as fuzzy inputs, and establishing a fuzzy rule base of "large / medium / small deviation" and "fast / medium / slow rate of change." The PID parameter corrections ΔKp, ΔKi, and ΔKd are dynamically output. When |e(t)|>1K, the weight of Kp is increased to achieve rapid convergence; when |e(t)|<0.01K, Kd is enhanced to suppress minor oscillations caused by the pulsed thermal load of the quantum chip; if the deviation persists for 10ms without being eliminated, Ki is gradually increased to eliminate steady-state error. The fuzzy rules are obtained through offline training of the step response data of the NV color center probe in different temperature zones. The DSP performs real-time lookup calculations with a parameter adjustment period of 50μs, matching the dual-channel demodulation rate.

[0056] In another alternative implementation, the control output can be generated using proportional, integral, and derivative algorithms via event-triggered predictive PID composite control. Specifically, PID calculation is activated only when the temperature deviation |e(t)| of the dual-channel demodulated output exceeds a threshold (e.g., 0.5 mK) or the temperature change rate |de(t) / dt| exceeds a warning value (e.g., 10 K / s). After triggering, the PID controller 32 does not directly use the current deviation but instead calls a simplified temperature field prediction model: based on the target area's heat capacity, diamond thermal conductivity, and historical power data of the actuator, it predicts the temperature trend for the next 5 ms. The predicted deviation e_pred(t+Δt) is then substituted into the PID algorithm to output the control quantity in advance. Furthermore, the model updates its parameters every 10 triggers to learn the actual response characteristics of the actuator.

[0057] Preferably, the PID parameters (Kp, Ki, Kd) can be optimized through adaptive algorithms or manual tuning to adapt to different system dynamic characteristics, thereby achieving fast response, small overshoot and high precision control.

[0058] The control signal output unit 33 is used to convert the control output quantity into a signal that can be recognized by the adjustment execution module 4.

[0059] Understandably, this unit converts the control output into a signal format recognizable by the regulation execution module 4, such as a pulse width modulation (PWM) signal, an analog voltage signal (e.g., 0-5V), or an analog current signal (e.g., 4-20mA). It should be noted that using PWM signals enables highly efficient power regulation, while analog voltage / current signals facilitate interfacing with common temperature control drive devices, enhancing the system's compatibility and flexibility at the execution level.

[0060] The adjustment execution module 4 is connected to the PID temperature control module 3 and is used to adjust the temperature of the target area according to the control signal. Understandably, the purpose of setting up the adjustment execution module 4 is to transform the control decisions generated by the PID temperature control module 3 into actual physical control actions, and to directly apply precise power output to the target area to complete the final execution stage of temperature closed-loop control.

[0061] Furthermore, the adjustment execution module 4 includes, Heating unit 41 is used to heat the target area; It should be noted that the heating unit 41, as the actuator for temperature increase, needs to possess the characteristics of rapid response and precise temperature control. Specifically, the heating unit 41 can employ a high-power-density thin-film resistance heater or a semiconductor cooling chip operating in heating mode. Preferably, a miniaturized thin-film resistance heater can be directly integrated near the target area to achieve localized rapid heating and reduce thermal delay. It is important to emphasize that the power capacity and thermal response speed of the heating unit 41 should meet the heating rate and maximum temperature requirements of the system, ensuring that temperature increase is completed within milliseconds.

[0062] Cooling unit 42 is used to cool the target area; Understandably, the cooling unit 42 plays a crucial role in reducing temperature, especially in applications requiring rapid cooling. Specifically, the cooling unit 42 can be a semiconductor cooling chip operating in cooling mode, a micro-circulating water cooling system, or a thermoelectric cooler based on the Peltier effect. Preferably, semiconductor cooling chips offer advantages such as no moving parts, rapid response, and high control precision, making them particularly suitable for micro- and nano-scale temperature control. It should be noted that the selection of the cooling unit 42 must comprehensively consider its cooling capacity, cooling rate, and minimum achievable temperature to meet the cooling requirements of the system under different operating conditions.

[0063] The drive and power regulation unit 43 is used to adjust the power output of the heating unit 41 or the cooling unit 42 according to the control signal.

[0064] It should be noted that the drive and power regulation unit 43 is the precision power amplifier of this module, and its performance directly determines the accuracy and stability of temperature control. Specifically, this unit includes a power amplifier circuit and a precision drive circuit, which can precisely adjust the magnitude and direction of the current flowing to the heating unit 41 or the cooling unit 42 according to the control signal (such as a PWM signal or an analog voltage signal) output by the PID control module.

[0065] Understandably, employing a high-efficiency switching power amplifier circuit based on MOSFETs or IGBTs can achieve both fast power response and reduced energy loss. Furthermore, this unit should have an automatic switching function for heating / cooling modes, capable of automatically selecting the appropriate execution unit based on the polarity of the control signal.

[0066] Preferably, the regulation execution module 4 in this system achieves bidirectional temperature regulation capability through the coordinated control of the heating and cooling units 42 by the drive and power regulation unit 43. From receiving control signals to precise power output and then to rapid heat transfer, this execution chain is seamlessly connected with the high-precision temperature sensing and intelligent PID control at the front end, jointly ensuring that the entire system can achieve millisecond-level or even microsecond-level stable temperature control, meeting the extreme temperature stability requirements of high-end applications such as quantum computing.

[0067] System control and human-computer interaction module 5 is responsible for the overall coordination of the system, data management and user interface.

[0068] Furthermore, the system control and human-machine interaction module 5 includes, The main control unit is responsible for coordinating the work of each module, executing PID control algorithms, managing data flow, and communicating with the human-machine interface. The main control unit can also integrate data storage functions.

[0069] It should be noted that the main control unit uses a high-performance microcontroller (MCU, such as the ARM Cortex-M series) or an embedded processor (e.g., an ARM-based microcontroller).

[0070] The data storage and recording unit is used to store historical temperature data, control parameters, system operating status, and alarm information.

[0071] It should be noted that the data can be stored in non-volatile memory (such as NAND Flash, SD card) to facilitate long-term data analysis and fault diagnosis.

[0072] The interactive interface provides an intuitive user interface for setting target temperatures, displaying real-time temperature curves, viewing system status, adjusting PID parameters, and performing system calibration.

[0073] Remote monitoring and operation can be achieved by using a color touchscreen, LCD display combined with buttons, or by connecting to a PC host computer software via USB / Ethernet interface.

[0074] In use, after the user sets the target temperature, a 532nm laser excites the NV color center of the nanodiamond to produce fluorescence, while the microwave generator applies a frequency modulation signal. The dual-channel lock-in amplifier 22 uses the microwave modulation frequency as a reference to synchronously demodulate the two resonance peak components or I / Q quadrature components in the fluorescence signal. After high-precision analog-to-digital conversion and digital signal processing, the zero-field splitting parameter D value is extracted and then converted into the actual temperature. The PID controller 32 calculates the deviation between the temperature value and the target value in real time, generates a control quantity through a proportional-integral-derivative algorithm, and converts it into a PWM signal to drive the semiconductor cooling chip or heater to adjust the temperature of the target area. During this process, the temperature change is instantaneously sensed by the NV color center probe, and the fluorescence signal changes accordingly, forming a microsecond-level fast feedback closed loop. The system status is displayed in real time on the human-machine interface, realizing high-precision dynamic stability control at the milliKelvin level.

[0075] In summary, the beneficial effects of the temperature control system based on NV centers of this invention are as follows: by integrating the high sensitivity of diamond NV center quantum sensing with dual-channel demodulation technology, it breaks through the performance limits of traditional temperature sensors at the micro-nano scale, achieving precise local temperature sensing with milliKelvin-level accuracy and microsecond-level response speed; thanks to the synergistic optimization of diamond's ultra-high thermal conductivity and PID closed-loop control, the system can not only achieve rapid dynamic temperature stabilization of micron / nano-scale target areas in application scenarios such as quantum chips and micro-nano electronic devices, but also effectively suppress common-mode noise such as laser power fluctuations and electromagnetic interference through the dual-channel structure, significantly improving robustness.

[0076] Example 3 illustrates a schematic scheme for a temperature control system based on NV color centers. It should be noted that the technical solution of this NV color center-based temperature control method belongs to the same concept as the aforementioned NV color center-based temperature control system. Details not described in detail in this embodiment can be found in the description of the aforementioned NV color center-based temperature control system.

[0077] Reference Figure 6 This embodiment also provides a temperature control method based on NV color centers, including: S100: The temperature change of the target area is sensed in real time through the diamond NV color center temperature sensing module 1, and the corresponding fluorescence signal is generated. S200: The fluorescence signal is demodulated and processed by the dual-channel demodulation and signal processing module 2 to extract the actual temperature value; S300: The PID temperature control module 3 compares the actual temperature value with the target temperature value and generates a control signal based on the deviation. S400: The temperature of the target area is adjusted by the adjustment execution module 4 according to the control signal; The extracted actual temperature value is continuously fed back to the PID temperature control module 3 to form a closed-loop control.

[0078] Furthermore, extract the actual temperature value, including, By utilizing microwave modulation and dual-channel phase-locked demodulation technology, the signals of two resonance peaks or the I / Q components of the signal in the optically detected magnetic resonance spectrum can be processed simultaneously. The common-mode noise is suppressed and the change in the zero-field splitting parameter D is calculated. The actual temperature value is then retrieved through a pre-calibrated temperature-frequency relationship.

[0079] Furthermore, control signals are generated, including, Using the PID algorithm, the control output is calculated based on the temperature deviation, and the control output is converted into a pulse width modulation signal or an analog voltage / current signal.

[0080] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not 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 technical solutions 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 temperature control system based on NV color centers, characterized in that: include, The diamond NV color center temperature sensing module (1) is used to sense the temperature change of the target area in real time and generate the corresponding fluorescence signal. The dual-channel demodulation and signal processing module (2) is connected to the diamond NV color center temperature sensing module (1) and is used to extract the actual temperature value from the fluorescence signal. The PID temperature control module (3) is connected to the dual-channel demodulation and signal processing module (2) and is used to generate a control signal based on the deviation between the actual temperature value and the target temperature value. The adjustment execution module (4) is connected to the PID temperature control module (3) and is used to adjust the temperature of the target area according to the control signal; The actual temperature value is continuously fed back to the PID temperature control module (3) to form a closed-loop control.

2. The temperature control system based on NV color centers as described in claim 1, characterized in that: The diamond NV color center temperature sensing module (1) includes, Diamond NV color center probe (11); A laser excitation unit (12) is used to emit a laser to excite the diamond NV color center probe (11) to generate fluorescence; A fluorescence collection and filtering unit (13) is used to collect the fluorescence and filter out the excitation laser; A photodetector (14) is used to convert the filtered fluorescence signal into an electrical signal.

3. The temperature control system based on NV color centers as described in claim 2, characterized in that: The dual-channel demodulation and signal processing module (2) includes, A microwave generation and modulation unit (21) is used to generate modulated microwaves and couple them to the diamond NV center probe (11) to control the spin state of the NV center. A dual-channel lock-in amplifier (22) is used to synchronously demodulate the electrical signal with reference to the modulation frequency of the modulated microwave; The data acquisition and digitization unit (23) is used to perform analog-to-digital conversion on the analog demodulated signal output by the dual-channel lock-in amplifier; The digital signal processing unit (24) is used to process the digitized signal and calculate the actual temperature value based on the pre-calibrated temperature-frequency relationship.

4. A temperature control system based on NV color centers as described in claim 3, characterized in that: The PID temperature control module (3) includes, The error calculation unit (31) is used to calculate the deviation between the actual temperature value and the target temperature value; PID controller (32) is used to generate control output based on the deviation using proportional, integral, and derivative algorithms; The control signal output unit (33) is used to convert the control output quantity into a signal that can be recognized by the adjustment execution module (4).

5. A temperature control system based on NV color centers as described in claim 4, characterized in that: The adjustment execution module (4) includes, Heating unit (41) is used to heat the target area; Refrigeration unit (42) is used to refrigerate the target area; The drive and power regulation unit (43) is used to regulate the power output of the heating unit (41) or the cooling unit (42) according to the control signal.

6. A temperature control system based on NV color centers as described in any one of claims 2-5, characterized in that: The diamond NV color center probe (11) is made of diamond containing a high concentration and uniform distribution of NV color centers. The diamond NV color center probe (11) is fabricated in nanoscale or microscale.

7. A temperature control system based on NV color centers as described in any one of claims 2-5, characterized in that: The laser wavelength emitted by the laser excitation unit (12) is 532nm or 520nm.

8. A temperature control method based on NV color centers, using the system described in any one of claims 1-7, characterized in that, include: The temperature change of the target area is sensed in real time by the diamond NV color center temperature sensing module (1), and the corresponding fluorescence signal is generated. The fluorescence signal is demodulated and processed by the dual-channel demodulation and signal processing module (2) to extract the actual temperature value; The actual temperature value is compared with the target temperature value by the PID temperature control module (3), and a control signal is generated based on the deviation. The temperature of the target area is adjusted by the adjustment execution module (4) according to the control signal; The extracted actual temperature value is continuously fed back to the PID temperature control module (3) to form a closed-loop control.

9. The temperature control method based on NV color centers as described in claim 8, characterized in that: The generation control signal includes, Using a PID algorithm, the control output is calculated based on the temperature deviation, and the control output is converted into a pulse width modulation signal or an analog voltage / current signal.

10. The temperature control method based on NV color centers as described in claim 8, characterized in that: The extraction of the actual temperature value includes, By utilizing microwave modulation and dual-channel phase-locked demodulation technology, the signals of two resonance peaks or the I / Q components of the signal in the optically detected magnetic resonance spectrum can be processed simultaneously. The common-mode noise is suppressed and the change in the zero-field splitting parameter D is calculated. The actual temperature value is then inverted through a pre-calibrated temperature-frequency relationship.

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