Automated calibration of logical gate fidelities based on neutral atom quantum computing systems

Abstract

This invention discloses an automatic calibration method for logic gates based on a neutral atom quantum computing system, and also discloses an automatic calibration method for logic gate fidelity based on a neutral atom quantum computing system. The method performs self-calibration on the fidelity of a two-qubit gate, including 420nm laser pointing self-calibration, 1013nm laser pointing self-calibration, Rydberg excitation Rabi frequency self-calibration, and single-photon Rabi frequency self-calibration; then it performs self-calibration on the ORMD waveform and ORMD phase; and finally, it performs self-calibration on the fidelity of an addressing single-qubit gate, including 795nm Raman light pointing self-calibration and single-qubit gate Rabi frequency self-calibration. This invention performs parameter self-calibration at fixed intervals to ensure that the logic gate fidelity remains at a high level. Without involving the installation of additional high-resolution laser position detectors, it uses a fully automated process to calibrate the fidelity of quantum logic gates, saving space in the physical system and the manpower costs required for calibration.

Description

Technical Field

[0001] This invention belongs to the field of quantum computing technology, specifically relating to automatic calibration logic gates based on neutral atom quantum computing systems, and also to a method for maintaining the fidelity of automatic calibration logic gates based on neutral atom quantum computing systems. Background Technology

[0002] Quantum computing circuits can be broken down into a series of single-qubit and two-qubit quantum gates, and the fidelity of quantum computing is also limited by the fidelity of single-qubit and two-qubit gates. Significant progress has been made in improving the fidelity of quantum gate operations in neutral atom systems. In 2023, the MD Lukin group at Harvard University achieved a fidelity greater than 99.5% for two-qubit gates using two-photon excitation techniques at 420nm and 1013nm. In 2018, the Zhan Mingsheng group at the Institute of Precision Measurement and Control, Chinese Academy of Sciences, achieved a fidelity of 0.99995 for microwave global single-qubit manipulation, and in 2024, they achieved a fidelity of 0.996 for addressable single-qubit gates using Raman spectroscopy.

[0003] The operational fidelity of existing technologies involving ORMD two-bit gates and Raman optical addressing single-bit gates is highly dependent on the stability of various parameters of the laser used. Drifts in laser power, frequency, and pointing can cause a loss in the fidelity of quantum circuits. In addition to ensuring the stability of various optical components and the external environment, it is also necessary to periodically calibrate the operational fidelity of the gates. This usually requires a laser position detector with extremely high resolution and a set of supporting monitoring devices. The calibration operation also requires a lot of time and manpower. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in the prior art by providing an automatic calibration logic gate based on a neutral atom quantum computing system, and also to provide a method for maintaining the fidelity of the automatic calibration logic gate based on a neutral atom quantum computing system.

[0005] The above-mentioned objectives of the present invention are achieved by the following technical means: An automatic calibration method for logic gate fidelity based on neutral atom quantum computing systems includes the following steps: Step 1: Two-bit gate fidelity self-calibration; Step 2: Self-calibration of ORMD waveform and ORMD phase; Step 3: Addressing single-bit gate fidelity self-calibration; The two-bit gate fidelity self-calibration in step 1 includes 420nm laser pointing self-calibration, 1013nm laser pointing self-calibration, Rydberg excitation Rabi frequency self-calibration, and single-photon Rabi frequency self-calibration. The addressing single-bit gate fidelity self-calibration in step 3 includes 795nm Raman beam pointing self-calibration and single-bit gate Rabi frequency self-calibration.

[0006] As described above, the self-calibration of the ORMD waveform and ORMD phase specifically includes the following steps: Set the iteration count n1 of the ORMD waveform and the iteration count n2 of the ORMD phase, and initialize them to 0 respectively. Set the waveform threshold. Phase threshold Iteration coefficients The interval time t; Step 2.1: After time t, proceed to step 2.2 to perform ORMD waveform verification; Step 2.2, ORMD waveform verification: Acquire the actual ORMD waveform and calculate the difference between the actual ORMD waveform and the target ORMD waveform. , the difference Comparison with waveform threshold T1: like If n2 > 0, then cancel the pause, resume the experiment, and jump to step 2.1; like If n2 = 0, then proceed to step 2.4; like Since n1=n2=0, pause the experiment and jump to step 2.3; like If n1 or n2 > 0, proceed directly to step 2.3; Step 2.3, ORMD waveform calibration: Add an ORMD waveform calibration layer to the driving waveform generated by the arbitrary waveform generator. Generate a new driving waveform, and set n1 = n1 + 1, then jump to step 2.2; Step 2.4, ORMD Phase Verification: Acquire the actual ORMD phase and calculate the difference between the actual ORMD phase and the target ORMD phase. , the difference With phase threshold Compare: like If n1 > 0, then cancel the pause, resume the experiment, and jump to step 2.1; like And if n1=n2=0, then there is no operation and the process jumps to step 2.1; like If n1=0 and n2>0, then proceed to step 2.2; like Since n1=n2=0, pause the experiment and jump to step 2.5; like If n1 or n2 > 0, proceed directly to step 2.5; Step 2.5, ORMD phase calibration: Add to the phase of the driving waveform to generate a new driving waveform, and let n2 = n2 + 1, then jump to Step 2.4.

[0007] As described above, the self-calibration of the 420nm laser pointing specifically includes the following steps: Step 1.1, Turn on the 420nm laser switch to cause optical frequency shift of the atoms; set the counts n3 = m3 = 0, the target row number T in the calibrated atomic array, the calibration accuracy , set the threshold T3, and the control coefficient ; Step 1.2, Scan the microwave frequency to obtain the global microwave flip absorption peak. After averaging the data of each row, perform Gaussian fitting with the microwave frequency as the horizontal axis to obtain the center frequency value of the absorption peak. Then, perform a second Gaussian fitting with the center frequency values of the absorption peaks of all row data as the horizontal axis with the row number, and the row number corresponding to the peak value after the second Gaussian fitting is the central value u1. The central value u1 is the row number of the atoms corresponding to the laser center, and calculate the difference =(u1 - T); If the fitting fails, pause the experiment and alarm; Step 1.3, Compare the difference with the threshold T3. If the difference is less than the threshold T3, then jump to Step 1.4; otherwise, adjust the output of the voltage controller to adjust the Y-axis voltage of the second electro-control mirror of the 420nm laser , and then jump to Step 1.2; Step 1.4, Calculate the Gaussian amplitude An1 obtained from the second Gaussian fitting in Step 1.2. If An1 ≥ An1-1 and m3 = 0, or n3 = 0, then adjust the X-axis voltage of the second electro-control mirror of the 420nm laser , n3 = n3 + 1, and jump to Step 1.2; if An1 < An1-1, then make , and adjust the X-axis voltage of the second electro-control mirror of the 420nm laser , n3 = n3 + 1, m3 = m3 + 1, and jump to Step 1.2; if An1 < An1-1 and m3 > 0, then adjust the X-axis voltage of the second electro-control mirror of the 420nm laser , and jump to Step 1.5 for the self-calibration of the 1013nm laser pointing; Among them, An1 is the Gaussian amplitude obtained from the second Gaussian fitting when performing Step 1.2 this time, and An1-1 is the Gaussian amplitude obtained from the second Gaussian fitting when performing Step 1.2 last time; The self-calibration of the 1013nm laser pointing specifically includes the following steps: Step 1.5: Turn on the 1013 nm laser switch to cause optical frequency shift of the atoms; set the count n4 = m4 = 0, calibrate the target row number T, and calibration accuracy , set the threshold T4, and control coefficient , Step 1.6: Scan the microwave frequency to obtain the global microwave flip absorption peak. After averaging each row of data, perform Gaussian fitting with the microwave frequency as the horizontal axis to obtain the center frequency value of the absorption peak. Then, perform a second Gaussian fitting with the center frequency values of the absorption peaks of all data as the horizontal axis using the row number, and obtain the row number corresponding to the peak after the second Gaussian fitting as the center value u2, and calculate the difference = (u2 - T); if the fitting fails, pause the experiment and give an alarm; Step 1.7: Compare the difference with the threshold T4. If the difference is less than the threshold T4, jump to Step 1.8; otherwise, adjust the output of the voltage controller to adjust the Y-axis voltage of the first electro-control mirror of the 1013 nm laser , and then jump to Step 1.6; Step 1.8: Calculate the Gaussian amplitude An2 obtained from the second Gaussian fitting in Step 1.6. If An2 ≥ An2-1 and m4 = 0, or n4 = 0, then adjust the X-axis voltage of the first electro-control mirror of the 1013 nm laser , n4 = n4 + 1, and jump to Step 1.6; if An2 < An2-1, then make , adjust the X-axis voltage of the first electro-control mirror of the 1013 nm laser , n4 = n4 + 1, m4 = m4 + 1, and jump to Step 1.6; if An2 < An2-1 and m4 > 0, then adjust the X-axis voltage of the first electro-control mirror of the 1013 nm laser , and jump to Step 1.9 for Rydberg excitation Rabi frequency self-calibration; where, An2 is the Gaussian amplitude obtained from the second Gaussian fitting when performing Step 1.6 this time, and An2-1 is the Gaussian amplitude obtained from the second Gaussian fitting when performing Step 1.6 last time.

[0008] The above-mentioned Rydberg excitation Rabi frequency self-calibration specifically includes the following steps: Step 1.9: Set the target Rabi frequency , set the threshold t1, control coefficient , the number of single-photon Rabi frequency scans n5, and the scan step size s; Step 1.10: When performing Rydberg excitation, scan the frequency of the 1013 nm laser, and use a Gaussian function to fit to obtain the center frequency value u3 of the absorption peak; Step 1.11: Fix the center frequency value u3, scan the 420nm laser action time, and obtain the Rabi oscillation by fitting with a damped sine function. Pulse time If the fitting fails, the experiment is paused and an alarm is triggered; if the fitting is successful, the voltage locked to the 420nm laser by the power-stabilized PID controller is read, and the voltages of the power detector and the ORMD waveform detector are also read. Step 1.12: Calculate the difference Compare the differences Does it exceed the threshold t1? If the difference is... If the threshold t1 is exceeded, the lockout voltage of the PID controller will be adjusted to stabilize the power of the 420nm laser. If the result is negative, proceed to step 1.10; otherwise, proceed to step 1.13 to perform single-photon Rabi frequency self-calibration.

[0009] As described above, single-photon Rabi frequency self-calibration specifically includes the following steps: Step 1.13: Perform Rydberg excitation and scan the frequency of the 1013nm laser to obtain the actual evolution waveforms of single atoms and dual atoms with the 1013nm laser frequency, respectively. Step 1.14: Calculate the difference D between the actual evolution waveform and the theoretical evolution waveform, adjust the locking voltage s of the power stabilizing PID controller for the 420nm laser, adjust the locking voltage -s of the power stabilizing PID controller for the 1013nm laser, and jump to step 1.10; until the number of times n5 is reached, jump to step 1.15. Step 1.15: Fit the difference D as the vertical axis and the locking voltage of the 420nm laser by the power-stabilized PID controller as the horizontal axis. Find the lowest point as the optimal point for two-bit gate fidelity. Feed back the locking voltage of the 420nm laser by the power-stabilized PID controller and the locking voltage of the 1013nm laser by the power-stabilized PID controller corresponding to the optimal point for two-bit gate fidelity to the central control computer. The calibration is complete.

[0010] As described above, the self-calibration of the 795nm Raman beam orientation specifically includes the following steps: Step 3.1: Set the X-axis frequency scanning range: Initial position X0 of the X-axis frequency, precision ΔX, number of scans nx, current number of scans is recorded as n6, initialize n6=0; update the X-axis frequency X=X+X0; Step 3.2: Scan the 795nm Raman light interaction time to obtain single-bit Gate Rabi oscillations. Each atom is independently fitted using a damped sine function to obtain the corresponding oscillation for each atom. Pulse duration w2; Step 3.3: Update the X-axis frequency X = X + ΔX, n6 = n6 + 1, jump to step 3.2, until n6 = nx; Step 3.4: Summarize the results For pulse time w2, with the corresponding X-axis frequency as the horizontal axis, perform Gaussian fitting to obtain the center X-axis frequency value X' of the absorption peak of the Gaussian fitting, and update the X-axis frequency X = center X-axis frequency value X'; if the fitting fails, jump to step 3.1 to reset the X-axis frequency scanning range. Step 3.5: Set the Y-axis frequency scanning range: Initial position Y0 for scanning Y-axis frequency, precision ΔY, number of scans ny, current number of scans is recorded as n7=0; Update Y-axis frequency Y=Y+Y0; Step 3.6: Scan the 795nm Raman light interaction time to obtain single-qubit Gate Rabi oscillations. Each atom is independently fitted using a damped sine function to obtain... Pulse duration w3; Step 3.7: Update the Y-axis frequency Y = Y + ΔY, n7 = n7 + 1, jump to step 3.6, until n7 = ny; Step 3.8: Summarize the results For pulse time w3, with the corresponding Y-axis frequency as the horizontal axis, perform Gaussian fitting to obtain the center Y-axis frequency value Y' of the absorption peak of the Gaussian fitting, and update the Y-axis frequency Y = center Y-axis frequency value Y'; if the fitting fails, jump to step 3.5 to reset the Y-axis frequency scanning range. Step 3.9: Simultaneously perform steps 3.1 to 3.8 to address all atoms in the atomic array to construct the updated frequency table X'Y'; The single-bit gate-Labbi frequency self-calibration specifically includes the following steps: Step 3.10: Using the updated frequency table X'Y', scan the 795nm Raman light interaction time to obtain single-bit Gate Rabi oscillations. Fit each atom independently using a damped sine function to obtain new... Pulse timetable w'.

[0011] The automatic calibration logic gate based on the neutral atom quantum computing system includes a 420nm laser system and an atom array, as well as a monitoring system that includes an oscilloscope and a central control computer. The 420nm laser system includes a 420nm laser, a delayed beat frequency optical module, a target ORMD waveform generation module, a target ORMD phase monitoring module, and an actual ORMD waveform phase analysis module. The delayed beat frequency optical module includes a first collimator, an optical fiber, and a second collimator. The 420nm laser sequentially passes through a first half-wave plate and a first polarizing beam splitter. One of the 420nm laser beams after being split by the first polarizing beam splitter is used as the delayed beat frequency light and sequentially passes through the first collimator, the optical fiber, the second collimator, the fourth half-wave plate, and the beam splitter. The target ORMD waveform generation module includes an acousto-optic modulator and an arbitrary waveform generator. Another 420nm laser beam, after being split by the first polarization beam splitter, passes sequentially through the second half-wave plate and the second polarization beam splitter. One of the 420nm laser beams after being split by the second polarization beam splitter is input to the acousto-optic modulator, and the acousto-optic modulator outputs the 420nm laser of the target ORMD waveform. The acousto-optic modulator is connected to the arbitrary waveform generator. The arbitrary waveform generator outputs a driving waveform to the acousto-optic modulator. The central control computer drives the generation of the target ORMD waveform by adjusting the amplitude and phase of the driving waveform output by the arbitrary waveform generator. The target ORMD phase detection module includes an ORMD phase detector and a high-bandwidth oscilloscope. One of the 420nm laser beams of the target ORMD waveform, after being split by the first beam splitter, passes sequentially through the third half-wave plate and the beam splitter prism. After being combined with the delayed beat frequency light by the beam splitter prism, it passes sequentially through the ORMD phase detector, the high-bandwidth oscilloscope, and the central control computer. The central control computer obtains the target ORMD phase. The actual ORMD waveform phase analysis module includes a second electrically controlled mirror, a voltage controller, and an ORMD waveform detector. Another 420nm laser beam of the target ORMD waveform, which has passed through the first beam splitter, passes through the second beam splitter and the second electrically controlled mirror in sequence and enters the atomic array. After passing through the atomic array, the 420nm laser beam passes through the ORMD waveform detector, a high-bandwidth oscilloscope, and a central control computer in sequence. The central control computer analyzes and obtains the actual ORMD waveform and the actual ORMD phase. The second electrically controlled reflector is connected to a voltage controller, which is connected to a central control computer. The central control computer changes the angle at which the 420nm laser is incident on the atom array by changing the magnitude of the voltage signal output from the voltage controller to the second electrically controlled reflector.

[0012] It also includes a 795nm Raman optical system and a 1013nm laser system; The 795nm Raman optical system also includes 795nm Raman light and an addressable single-bit gate module. The addressable single-bit gate module includes a two-dimensional acousto-optic deflector and an arbitrary waveform generator. The 795nm Raman light is split by a third beam splitter, and one beam of 795nm Raman light enters the two-dimensional acousto-optic deflector. The two-dimensional acousto-optic deflector outputs the diffracted light of the 795nm Raman light to the atomic array. The two-dimensional acousto-optic deflector is connected to the arbitrary waveform generator, which is connected to a central control computer. The central control computer controls the arbitrary waveform generator to output radio frequency signals to the two-dimensional acousto-optic deflector. The central control computer adjusts the intensity and angle of the diffracted light of the 795nm Raman light by changing the amplitude and frequency of the radio frequency signal. The 1013nm laser system includes a 1013nm laser and a two-bit gate operation module. The two-bit gate operation module includes a first electrically controlled mirror, a power detector, and a voltage controller. The 1013nm laser sequentially passes through a fifth half-wave plate, a third polarizing beam splitter, and a fourth beam splitter. One of the 1013nm laser beams split by the fourth beam splitter is reflected by the first electrically controlled mirror and enters the atomic array. After passing through the atomic array, the 1013nm laser enters the power detector. The output signal of the power detector is output to an oscilloscope and transmitted to the central control computer. The first electrically controlled reflector is connected to a voltage controller. The central control computer changes the angle at which the 1013nm laser is incident on the atom array by changing the magnitude of the voltage signal output from the voltage controller to the first electrically controlled reflector.

[0013] It also includes a 795nm Raman optical system, a 1013nm laser system, and a 420nm laser system, all of which include power stabilization and monitoring modules; In the power stabilization and monitoring module of the 795nm Raman optical system, another 795nm Raman beam split by the third beam splitter passes through the first power stabilization detector and the power stabilization PID controller in sequence. The power stabilization PID controller outputs an error monitoring signal to the oscilloscope and transmits it to the central control computer. In the power stabilization and monitoring module of the 1013nm laser system, another 1013nm laser beam split by the fourth beam splitter passes through the second power stabilization detector and the power stabilization PID controller in sequence. The power stabilization PID controller outputs a power stabilization monitoring signal for the 1013nm laser to the oscilloscope and transmits it to the central control computer. In the power stabilization and monitoring module of the 420nm laser system, one of the 420nm laser beams with the target ORMD waveform split by the second beam splitter enters the second electrically controlled reflector, and the other 420nm laser beam with the target ORMD waveform passes through the third power stabilization detector and the power stabilization PID controller in sequence. The power stabilization PID controller outputs a power stabilization monitoring signal for the 420nm laser to the oscilloscope and transmits it to the central control computer. The 1013nm laser system and the 420nm laser system also include a frequency locking and monitoring module, which includes an electro-optic modulator, an ultra-stable cavity, and a frequency-locked PID controller. In the 1013nm laser system, one of the 1013nm laser beams split by the third polarization beam splitter sequentially passes through an electro-optic modulator, an ultra-stable cavity, and a frequency-locked PID controller for frequency locking. The frequency-locked PID controller also outputs a frequency-locked monitoring signal for the 1013nm laser and transmits it to the central control computer. One of the 1013nm laser beams split by the third polarization beam splitter enters the fourth beam splitter. The electro-optic modulator is connected to a microwave source, which is connected to a central control computer. The central control computer adjusts the frequency of the radio frequency signal input from the microwave source to the electro-optic modulator according to the monitoring signal to regulate the frequency shift of the electro-optic modulator. In the 420nm laser system, the other 420nm laser beam, after being split by the second polarization beam splitter prism, passes through an ultra-stable cavity and a frequency-locked PID controller in sequence for frequency locking. The frequency-locked PID controller also outputs a frequency locking monitoring signal for the 420nm laser and transmits it to the central control computer.

[0014] It also includes a microwave speaker, a fluxgate magnetometer, and a thermometer. The microwave speaker is connected to a microwave source, the fluxgate magnetometer is connected to an oscilloscope, and the thermometer is connected to a central control computer.

[0015] Compared with the prior art, the present invention has the following advantages: (1) This invention is applied to a miniaturized quantum computing prototype based on neutral atoms. It uses a fully automated process to automatically calibrate the fidelity of two-bit gate operations and the fidelity of addressing single-bit gate operations while minimizing human interference, thereby maximizing the fidelity of the prototype's computing environment.

[0016] (2) The fidelity of the quantum logic gate implemented based on the neutral atom quantum computing prototype depends on the various parameters of the laser used. In addition to ensuring the stability of the system parameters, the present invention calibrates the system parameters at fixed intervals to ensure that the fidelity of the logic gate is maintained at a high level. Without involving the installation of additional high-resolution laser position detectors, the present invention uses a fully automatic process to calibrate the fidelity of the quantum logic gate, saving space in the physical system and manpower costs required for calibration as much as possible, and maintaining the stable operation of the prototype system. Attached Figure Description

[0017] Figure 1 A schematic diagram of an automatic calibration logic gate; Figure labels and corresponding component names: 101-Third beam splitter; 102-Two-dimensional acousto-optic deflector; 103-First power stabilizing detector; 104-Fifth half-wave plate; 105-Third polarizing beam splitter prism; 106-Electro-optic modulator; 107-Ultra-stable cavity; 108-Fourth beam splitter; 109-First electrically controlled mirror; 110-Second power stabilizing detector; 111-Power detector; 112-First half-wave plate; 113-First polarizing beam splitter prism; 114-First collimator; 115-Second half-wave plate; 116-Second polarizing beam splitter prism; 117-Acousto-optic modulator; 118-First beam splitter; 119-Third half-wave plate; 120-Beam splitter prism; 121-Second collimator ; 122-Fourth half-wave plate; 123-ORMD phase detector; 124-Second beam splitter; 125-Third power stabilizing detector; 126-Second electrically controlled reflector; 127-ORMD waveform detector; 128-Microwave speaker; 201-795nm Raman light; 202-1013nm laser; 203-420nm laser; 204-Delayed beat frequency light; 301-Central control computer; 302-High bandwidth oscilloscope; 303-Microwave source; 304-Arbitrary waveform generator; 305-Voltage controller; 306-Power stabilizing PID controller; 307-Frequency locked PID controller; 308-Fluorescence meter; 309-Oscilloscope; 310-Thermometer. Detailed Implementation

[0018] To facilitate understanding and implementation of the present invention by those skilled in the art, the present invention will be further described in detail below with reference to embodiments. The embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Example 1:

[0019] like Figure 1 As shown, the automatic calibration logic gate based on the neutral atom quantum computing system includes an atom array, a 795nm Raman optical system, a 1013nm laser system, a 420nm laser system, and a monitoring system. The monitoring system includes an oscilloscope 309 and a central control computer 301. The 795nm Raman optical system includes a 795nm Raman beam 201, an addressing single-bit gate module, and a power stabilization and monitoring module. The power stabilization and monitoring module of the 795nm Raman optical system includes a first power stabilization detector 103 and a power stabilization PID controller 306. The 795nm Raman beam 201 is used for addressing single-bit gate operations. The 795nm Raman beam 201 is first split into two parts by a third beam splitter 101. One part of the 795nm Raman beam 201 enters the first power stabilization detector 103. The output signal of the first power stabilization detector 103 is transmitted to the power stabilization PID controller 306 (power stabilization proportional-integral-derivative controller) for power stabilization. The error monitoring signal of the power stabilization PID controller 306 is output to an oscilloscope 309. The oscilloscope 309 is connected to the central control computer 301, and the error monitoring signal of the 795nm Raman beam 201 is monitored on the central control computer 301.

[0020] The addressable single-bit gate module includes a two-dimensional acousto-optic deflector 102 and an arbitrary waveform generator 304. Another portion of the 795nm Raman light 201, which is split by the third beam splitter 101, enters the two-dimensional acousto-optic deflector 102 (AOD) and undergoes diffraction. The two-dimensional acousto-optic deflector 102 outputs the diffracted light of the 795nm Raman light 201 to the atomic array (for performing single-bit flipping operation on a single atom). The diffraction of the 795nm Raman light 201 is used to control the direction of the 795nm Raman light 201 to ensure that a single atom can be addressed. The intensity and angle of the diffracted light of the 795nm Raman light 201 are determined by the amplitude and frequency of the radio frequency signal output by the arbitrary waveform generator 304 (AWG) to the two-dimensional acousto-optic deflector 102. The arbitrary waveform generator 304 is connected to the central control computer 301, and the radio frequency signal output by the arbitrary waveform generator 304 is controlled by the central control computer 301.

[0021] The 1013nm laser 202 and the 420nm laser 203 are used for two-bit gate operations.

[0022] The 1013nm laser system includes a 1013nm laser 202, a two-bit gate operation module, a power stabilization and monitoring system, and a frequency locking and monitoring module. The frequency locking and monitoring module includes an electro-optic modulator 106, a super-stable cavity 107, and a frequency-locked PID controller 307. The 1013nm laser 202 first passes through a fifth half-wave plate 104 and a third polarization beam splitter prism 105 (PBS). The fifth half-wave plate 104 is used to change the laser polarization, and the third polarization beam splitter prism 105... The 5-beam splits the 1013nm laser 202 into two 1013nm laser beams 202 according to polarization. One of the 1013nm laser beams 202 enters the electro-optic modulator 106 (EOM) through an optical fiber. The electro-optic modulator 106 shifts the frequency of the input 1013nm laser 202. The electro-optic modulator 106 is connected to the microwave source 303, which inputs a radio frequency signal to the electro-optic modulator 106. The magnitude of the frequency shift in the electro-optic modulator 106 is controlled by the frequency of the radio frequency signal input from the microwave source 303. The microwave source 303 also... The central control computer 301 is connected and controls the opening and closing of the electro-optic modulator 106. The 1013nm laser 202, after frequency shifting by the electro-optic modulator 106, is incident into the ultra-stable cavity 107. The ultra-stable cavity 107 is a customized dual-wavelength cavity of 420nm and 1013nm, used to provide laser frequency references for the 1013nm laser 202 and the 420nm laser 203. The ultra-stable cavity 107 outputs a transmission peak signal to the frequency-locked PID controller 307 for frequency locking. The frequency-locked PID controller 307 outputs a signal corresponding to the 1013nm laser 202. The frequency lock monitoring signal of the 13nm laser 202 is sent to the oscilloscope 309 and then further transmitted to the central control computer 301 for monitoring. The laser frequency locked by the ultra-stable cavity 107 is determined by the cavity itself and is regarded as a fixed frequency. The laser frequency of the 1013nm laser 202 can be changed by changing the frequency shift of the electro-optic modulator 106. The frequency lock PID controller 307 modulates the 1013nm laser 202 PZT (piezoelectric ceramic) to lock the laser frequency. The locking parameters are controlled by the central control computer 301.

[0023] The power stabilization and monitoring system of the 1013nm laser system includes a second power stabilization detector 110 and a power stabilization PID controller 306. Another 1013nm laser beam 202, which is split by the third polarization beam splitter 105, is split into a small portion of the 1013nm laser 202 by the fourth beam splitter 108 and enters the second power stabilization detector 110. The output signal of the second power stabilization detector 110 is output to the power stabilization PID controller 306 for power stabilization. The power stabilization PID controller 306 outputs a power stabilization monitoring signal (monitor) for the 1013nm laser 202 to the oscilloscope 309 and is transmitted to the central control computer 301 for monitoring via the oscilloscope 309.

[0024] The two-bit gate operation module includes a first electrically controlled reflector 109, a power detector 111, and a voltage controller 305. The 1013nm laser 202, split by the fourth beam splitter 108, is reflected by the first electrically controlled reflector 109 and enters the atomic array. The first electrically controlled reflector 109 is connected to the voltage controller 305, which outputs a voltage signal to the first electrically controlled reflector 109. The voltage controller 305 is also connected to the central control computer 301. The angle of the first electrically controlled reflector 109 is controlled by the magnitude of the voltage signal output by the voltage controller 305. Changing the voltage signal changes the angle at which the 1013nm laser 202 enters the atomic array. The voltage controller 305 is connected to the central control computer 301, and the magnitude of the voltage signal output by the voltage controller 305 is controlled by the central control computer 301. After passing through the atomic array, the 1013nm laser 202 enters the power detector 111 through the second electrically controlled reflector 126. The output signal of the power detector 111 is output to the oscilloscope 309.

[0025] The 420nm laser system includes a 420nm laser 203, a delayed beat frequency optical module, a target ORMD waveform generation module, a target ORMD phase detection module, an actual ORMD waveform phase analysis module, a power stabilization and monitoring system, and a frequency locking and monitoring module. The delayed beat frequency optical module includes a first collimator 114, an optical fiber, and a second collimator 121. The 420nm laser 203 first passes through a first half-wave plate 112 and a first polarization beam splitter prism 113 (PBS). The first polarization beam splitter prism 113 splits the 420nm laser 203 into two beams according to polarization. One of the 420nm laser beams 203 enters the first collimator 114 and is coupled into the optical fiber, serving as the delayed beat frequency light 204. The delayed beat frequency light 204 passes through the optical fiber and then enters the second collimator 121. The delayed beat frequency light 204 emitted from the second collimator 121 is polarized by a fourth half-wave plate 122 and then enters the beam splitter prism 120 (BS).

[0026] The frequency locking and monitoring module of the 420nm laser system includes an ultra-stable cavity 107 and a frequency-locking PID controller 307. Another 420nm laser beam 203 is then split by a second half-wave plate 115 and a second polarization beam splitter prism 116. One of the 420nm laser beams 203 after being split by the second polarization beam splitter prism 116 enters the ultra-stable cavity 107 and the frequency-locking PID controller 307 to lock the laser frequency. The monitor signal output by the frequency-locking PID controller 307 is connected to an oscilloscope 309 and transmitted to the central control computer 301 for monitoring.

[0027] The target ORMD waveform generation module includes an acousto-optic modulator 117 and an arbitrary waveform generator 304. Another 420nm laser 203, after being split by the second polarization beam splitter prism 116, is diffracted by the acousto-optic modulator 117 (AOM). The acousto-optic modulator 117 is connected to the arbitrary waveform generator 304. The arbitrary waveform generator 304 outputs a driving waveform to the acousto-optic modulator 117. The intensity of the diffracted light output by the acousto-optic modulator 117 is determined by the amplitude of the driving waveform output by the arbitrary waveform generator 304. The driving waveform is controlled by the arbitrary waveform generator 304 through the central control computer 301. The amplitude and phase of the signal waveform are generated by the non-resonant modulation pulse scheme (ORMD scheme). The laser waveform generated by the driving is the target ORMD waveform.

[0028] The target ORMD phase detection module includes an ORMD phase detector 123 and a high-bandwidth oscilloscope 302. A small portion of the diffracted light output from the acousto-optic modulator 117 is split off by the first beam splitter 118, and then its polarization is corrected by the third half-wave plate 119. After being combined with the delayed beat frequency light 204 by the beam splitter prism 120, the combined beam enters the ORMD phase detector 123. The ORMD phase detector 123 outputs a detection signal to the high-bandwidth oscilloscope 302 (e.g., 1 GHz bandwidth), and the signal is transmitted to the central control computer 301 via the high-bandwidth oscilloscope 302. The central control computer 301 analyzes the signal to obtain the target ORMD phase.

[0029] The power stabilization and monitoring system of the 420nm laser system includes a third power stabilization detector 125 and a power stabilization PID controller 306. The other part of the 420nm laser 203, which is split by the first beam splitter 118, is then split by the second beam splitter 124, and a small part of the 420nm laser 203 enters the third power stabilization detector 125. The third power stabilization detector 125 outputs a detection signal to the power stabilization PID controller 306 for power stabilization. The power stabilization PID controller 306 outputs a monitor signal to the oscilloscope 309 and transmits it to the central control computer 301 for monitoring.

[0030] The actual ORMD waveform phase analysis module includes a second electrically controlled reflector 126, a voltage controller 305, and an ORMD waveform detector 127. The remaining portion of the 420nm laser 203, split by the second beam splitter 124, is reflected by the second electrically controlled reflector 126 and enters the atomic array. The second electrically controlled reflector 126 is connected to the voltage controller 305, which outputs a voltage signal to the second electrically controlled reflector 126. The angle of the second electrically controlled reflector 126 is controlled by the magnitude of the voltage signal output by the voltage controller 305; changing the magnitude of the voltage signal changes the 42nm wavelength. The 0nm laser 203 is incident on the atomic array at an angle. The voltage controller 305 is connected to the central control computer 301, and the voltage signal output by the voltage controller 305 is controlled by the central control computer 301. After passing through the atomic array, the 420nm laser 203 enters the non-resonant modulation pulse waveform detector (ORMD waveform detector 127) through the first electrically controlled reflector 109. The ORMD waveform detector 127 outputs a signal to the high-bandwidth oscilloscope 302, and then transmits it to the central control computer 301 for analysis to obtain the actual ORMD waveform and the actual ORMD phase.

[0031] It also includes a microwave speaker 128 that performs global single-bit gate operations, a fluxgate magnetometer 308, and a thermometer 310 that monitors the ambient temperature. The microwave speaker 128 is placed next to the atomic array, and the microwave source 303, controlled by the central control computer 301, outputs microwave signals of a specific frequency and amplitude to the microwave speaker 128. The fluxgate magnetometer 308 is connected to an oscilloscope 309, which provides a background magnetic field. The central control computer 301 monitors the background magnetic field through the oscilloscope 309. The thermometer 310 is connected to the central control computer 301, which monitors the ambient temperature through the thermometer 310. Example 2:

[0032] The method for automatically calibrating the fidelity of logic gates based on a neutral atom quantum computing system, utilizing the automatic calibration logic gates for a neutral atom quantum computing system described in Example 1, includes the following steps: In this embodiment, the signals from the third power stabilization detector 125 of the 420nm laser 203, the second power stabilization detector 110 of the 1013nm laser 202, the first power stabilization detector 103 of the 795nm Raman light 201, the frequency lock monitoring signal between the 420nm laser 203 and the 1013nm laser 202, the ORMD waveform detector 127, the ORMD phase detector 123, and the background magnetic field signal provided by the fluxgate magnetometer 308 are all connected to the oscilloscope 309 and then monitored by the central control computer 301. The fixed ambient temperature signal provided by the thermometer 310 is directly connected to the central control computer 301 for monitoring. The central control computer 301 sets a threshold for each signal, and operates normally when all signals do not exceed the threshold. When the signals from the third power stabilization detector 125 of the 420nm laser 203, the second power stabilization detector 110 of the 1013nm laser 202, the first power stabilization detector 103 of the 795nm Raman light 201, and the frequency lock monitoring signals of the 420nm laser 203 and the 1013nm laser 202 exceed the threshold, a systemic error is identified, the experiment is paused, an alarm is issued, and the experimenter is awaited to intervene and repair the error. When the background magnetic field signal provided by the fluxgate magnetometer 308 and the fixed ambient temperature signal provided by the thermometer 310 exceed the threshold, an environmental error is identified, an alarm is issued, the experiment is not interrupted, and the curve is continuously recorded. When the signals from the ORMD waveform detector 127 or the ORMD phase detector 123 exceed the threshold, an ORMD error is identified, and the monitoring and self-calibration of the ORMD waveform and phase are initiated.

[0033] Step 1: Two-bit gate fidelity self-calibration. This includes sequentially performing 420nm laser pointing self-calibration, 1013nm laser pointing self-calibration, Rydberg excitation Rabi frequency self-calibration, and single-photon Rabi frequency self-calibration. Specifically, it includes the following steps: 420nm laser pointing self-calibration: Step 1.1: Turn on the 420nm laser 203 switch to cause a frequency shift in the atoms; the closer the atom is to the laser center, the greater the frequency shift. Set the count n3=m3=0, calibrate the target row number T in the atom array, and adjust the calibration accuracy. =3V ( (The smaller the value, the higher the precision), set the threshold T3, and control the coefficient. .

[0034] Step 1.2: Scan the microwave frequency to obtain the global microwave reversal absorption peak. Average the data for each row and perform Gaussian fitting with the microwave frequency as the horizontal axis to obtain the center frequency value of the absorption peak. Then, perform a second Gaussian fitting with the center frequency values ​​of the absorption peaks of all rows of data and the row number as the horizontal axis. The row number corresponding to the peak value after the second Gaussian fitting is the center value u1. The center value u1 is the atomic row number corresponding to the laser center. Calculate the difference. = (u1-T); If fitting fails, pause the experiment and issue an alarm.

[0035] The data obtained by scanning in step 1.2 is the atomic retention rate. Define the two energy levels of the atom as |0> and |1>. Initially, the atom is prepared in the |0> state. When detecting, the atoms in the |1> state are removed. The microwave acting on the atom flips it between the two energy levels. Therefore, the atomic retention rate can characterize the effect of the microwave on it. When the microwave acts, the 420-nm laser 203 or the 1013-nm laser 202 irradiating on the atom will cause an optical frequency shift of the atom, and then the central frequency of the microwave action will shift. The shift magnitude is related to the magnitude of the optical frequency shift.

[0036] Step 1.3. Compare the difference Whether it is less than the threshold T3. If the difference is less than the threshold T3, then jump to step 1.4; otherwise, adjust the output of the voltage controller 305 to adjust the Y-axis voltage of the second electro-control mirror 126 of the 420-nm laser 203 and then jump to step 1.2.

[0037] Step 1.4. Calculate the Gaussian amplitude (i.e., the absorption peak amplitude) An1 obtained by the second Gaussian fitting in step 1.2. If n3 = 0 or (An1 ≥ An1-1, m3 = 0), then adjust the X-axis voltage of the second electro-control mirror 126 of the 420-nm laser 203 n3 = n3 + 1, and jump to step 1.2; if An1 < An1-1, then make and then adjust the X-axis voltage of the second electro-control mirror 126 of the 420-nm laser 203 n3 = n3 + 1, m3 = m3 + 1, and jump to step 1.2; if An1 < An1-1 and m3 > 0, then adjust the X-axis voltage of the second electro-control mirror 126 of the 420-nm laser 203 and jump to step 1.5 for the self-calibration of the 1013-nm laser pointing.

[0038] Here, An1 is the Gaussian amplitude obtained by the second Gaussian fitting when step 1.2 is executed this time, and An1-1 is the Gaussian amplitude obtained by the second Gaussian fitting when step 1.2 was executed last time.

[0039] Self-calibration of the 1013-nm laser pointing: Step 1.5. Turn on the switch of the 1013-nm laser 202 to cause an optical frequency shift of the atom. The closer the atom is to the center of the laser, the greater the frequency shift. Set the counters n4 = m4 = 0, the calibration target row number T, and the calibration accuracy = 3V ( The smaller it is, the higher the accuracy), set the threshold T4, and the control coefficient .

[0040] Step 1.6: Scan the microwave frequency to obtain the global microwave flip absorption peak. After averaging each row of data, perform Gaussian fitting with the microwave frequency as the horizontal axis to obtain the center frequency value of the absorption peak. Then, perform a second Gaussian fitting with the center frequency values of the absorption peaks of all data using the row number as the horizontal axis. The row number corresponding to the peak after the second Gaussian fitting is the central value u2. Calculate the difference = (u2 - T); if the fitting fails, pause the experiment and give an alarm.

[0041] Step 1.7: Compare the difference Whether it is less than the threshold value. If so, jump to Step 1.8; otherwise, adjust the output of the voltage controller 305 to adjust the Y-axis voltage of the first electro-control mirror 109 of the 1013 nm laser 202 , and then jump to Step 1.6.

[0042] Step 1.8: Calculate the Gaussian amplitude An2 obtained from the second Gaussian fitting in Step 1.6. If n4 = 0 or (An2 ≥ An2-1, m4 = 0), then adjust the X-axis voltage of the first electro-control mirror 109 of the 1013 nm laser 202 , n4 = n4 + 1, jump to Step 1.6; if An2 < An2-1, then make , and adjust the X-axis voltage of the first electro-control mirror 109 of the 1013 nm laser 202 , n4 = n4 + 1, m4 = m4 + 1, jump to Step 1.6; if An2 < An2-1 and m4 > 0, then adjust the X-axis voltage of the first electro-control mirror 109 of the 1013 nm laser 202 , and jump to Step 1.9 for Rydberg excitation Rabi frequency self-calibration.

[0043] Here, An2 is the Gaussian amplitude obtained from the second Gaussian fitting when performing Step 1.6 this time, and An2-1 is the Gaussian amplitude obtained from the second Gaussian fitting when performing Step 1.6 last time.

[0044] Rydberg excitation Rabi frequency self-calibration: Step 1.9: Set the target Rabi frequency , set the threshold value t1, control coefficient , the number of single-photon Rabi frequency scans n5, and the scan step size s.

[0045] Step 1.10: When performing Rydberg excitation, scan the signal frequency output from the microwave source 303 to the electro-optic modulator 106, that is, scan the frequency of the 1013 nm laser 202, and use Gaussian function fitting to obtain the center frequency value u3 of the absorption peak.

[0046] Step 1.11: Fix the center frequency value u3, scan the action time of the 420nm laser 203, and obtain the Rabi oscillation by fitting with a damped sine function. Pulse time If the fitting fails, the experiment is paused and an alarm is triggered; if the fitting is successful, the voltage of the power stabilization PID controller 306 locking the 420nm laser 203 is read, and the voltages of the power detector 111 and the ORMD waveform detector 127 are read from the oscilloscope 309.

[0047] Step 1.12: Calculate the difference Compare the differences Does it exceed the threshold t1? If the difference is... If the threshold t1 is exceeded, the lockout voltage of the PID controller 306 for stabilizing the power of the 420nm laser 203 will be adjusted. If the result is negative, proceed to step 1.10; otherwise, proceed to step 1.13 to perform single-photon Rabi frequency self-calibration.

[0048] Single-photon Rabi frequency self-calibration: Step 1.13: The central control computer 301 activates the ORMD waveform by controlling the modulation signal input from the arbitrary waveform generator 304 to the acousto-optic modulator 117 of the 420nm laser 203, performs Rydberg excitation, and scans the signal frequency output from the microwave source 303 to the electro-optic modulator 106, that is, scans the frequency of the 1013nm laser 202, and obtains the actual evolution waveforms of single atoms and dual atoms with the frequency of the 1013nm laser 202.

[0049] Step 1.14: Calculate the difference D between the actual evolution waveform and the theoretical evolution waveform, adjust the locking voltage s of the power stabilizing PID controller 306 for the 420nm laser 203, adjust the locking voltage -s of the power stabilizing PID controller 306 for the 1013nm laser 202, and jump to step 1.10; until the number of times n5 is reached, jump to step 1.15.

[0050] Step 1.15: Fit the difference D as the vertical axis and the locking voltage of the power-stabilized PID controller 306 for the 420nm laser 203 as the horizontal axis. The lowest point found is the optimal point for two-bit gate fidelity. Feed back the locking voltage of the power-stabilized PID controller 306 for the 420nm laser 203 and the locking voltage of the power-stabilized PID controller 306 for the 1013nm laser 202 corresponding to the optimal point for two-bit gate fidelity to the main control computer 301. The calibration is complete.

[0051] Step 2: Perform self-calibration of the ORMD waveform and ORMD phase, specifically including the following steps: The initial values ​​for the ORMD waveform iteration number n1 and the phase iteration number n2 are set to 0, and the waveform threshold is set. Phase threshold Iteration coefficients , the interval time t.

[0052] Step 2.1: After time t, proceed to step 2.2 to perform ORMD waveform verification.

[0053] Step 2.2, ORMD Waveform Verification: The central control computer 301 controls the oscilloscope 309 to acquire the actual ORMD waveform and calculate the difference between the actual ORMD waveform and the target ORMD waveform. , the difference Compared with the waveform threshold T1, if If n2 > 0, then cancel the pause and resume the experiment (in this embodiment, the experiment is the quantum circuit calculation experiment; when the threshold is exceeded, it indicates a decrease in fidelity, so the ongoing quantum circuit calculation is paused and resumed after calibration), jump to step 2.1, wait for time t, and then proceed to the next ORMD waveform check; if And if n2=0, then proceed to step 2.4 to perform ORMD phase verification; if And if n1=n2=0, pause the experiment and proceed to step 2.3 to perform ORMD waveform calibration; if If n1 or n2 > 0, proceed directly to step 2.3 to perform ORMD waveform calibration.

[0054] Step 2.3, ORMD Waveform Calibration: The driving waveform (generated by the arbitrary waveform generator 304 controlled by the central control computer 301 and output to the acousto-optic modulator 117, which modulates the 420nm laser 203 according to the driving waveform to generate the target ORMD waveform) is calibrated by adding... Generate a new driving waveform and set n1=n1+1, then jump to step 2.2 to perform ORMD waveform verification again.

[0055] Step 2.4, ORMD Phase Verification: The central control computer 301 controls the oscilloscope 309 to acquire the actual ORMD phase and calculate the difference between the actual ORMD phase and the target ORMD phase. , the difference With threshold In comparison, if If n1 > 0, then cancel the pause, resume the experiment, jump to step 2.1, and wait for time t before proceeding to the next ORMD waveform check; if If n1=n2=0, then there is no operation, and the process jumps to step 2.1, waiting for time t before proceeding to the next ORMD waveform check; if If n1=0 and n2>0, then proceed to step 2.2 to perform ORMD waveform verification; if And if n1=n2=0, pause the experiment and proceed to step 2.5 for ORMD phase calibration; if If n1 or n2 > 0, proceed directly to step 2.5 for ORMD phase calibration.

[0056] Step 2.5, ORMD Phase Calibration: Add a phase adjustment to the driving waveform. Generate a new driving waveform and set n2=n2+1, then jump to step 2.4 to perform ORMD waveform verification again.

[0057] Step 3: Addressing single-bit gate fidelity self-calibration. This includes sequentially performing 795nm Raman beam pointing self-calibration and single-bit gate Rabi frequency self-calibration, specifically comprising the following steps: 795nm Raman beam pointing self-calibration system: Step 3.1: Set the X-axis frequency scanning range: Initial position X0 of the X-axis frequency, precision ΔX, number of scans nx, current number of scans is recorded as n6, initialize n6=0; update the X-axis frequency X=X+X0.

[0058] Step 3.2: Scan the interaction time of the 795nm Raman light 201 to obtain the single-bit Gate Rabi oscillation. Fit each atom independently using a damped sine function to obtain the corresponding oscillation for each atom. Pulse duration w2.

[0059] Step 3.3: Update the X-axis frequency X = X + ΔX, n6 = n6 + 1, jump to step 3.2, until n6 = nx.

[0060] Step 3.4: Summarize the results For pulse time w2, use the corresponding X-axis frequency as the horizontal axis to perform Gaussian fitting, obtain the center X-axis frequency value X' of the Gaussian fitted absorption peak, and update the X-axis frequency X = center X-axis frequency value X'; if the fitting fails, jump to step 3.1 to reset the X-axis frequency scanning range.

[0061] Step 3.5: Set the Y-axis frequency scanning range: Initial position Y0 for scanning Y-axis frequency, precision ΔY, number of scans ny, current number of scans is recorded as n7=0; Update Y-axis frequency Y=Y+Y0.

[0062] Among them, the X-axis frequency and Y-axis frequency are the X-axis frequency and Y-axis frequency (i.e., laser pointing) of the arbitrary waveform generator 304 input to the two-dimensional acousto-optic deflector 102 when addressing each atom of the atom array. The X-axis frequency and Y-axis frequency of all atoms in the atom array constitute the frequency table XY.

[0063] Step 3.6: Scan the interaction time of 795nm Raman light 201 to obtain single-qubit Gate Rabi oscillations. Each atom is independently fitted using a damped sine function to obtain... Pulse duration w3.

[0064] Step 3.7: Update the Y-axis frequency Y = Y + ΔY, n7 = n7 + 1, jump to step 3.6, until n7 = ny.

[0065] Step 3.8: Summarize the results For pulse time w3, use the corresponding Y-axis frequency as the horizontal axis to perform Gaussian fitting, obtain the center Y-axis frequency value Y' of the absorption peak of the Gaussian fitting, and update the Y-axis frequency Y = center Y-axis frequency value Y'; if the fitting fails, jump to step 3.5 to reset the Y-axis frequency scanning range.

[0066] Step 3.9: Simultaneously perform steps 3.1 to 3.8 to address all atoms in the atomic array to construct the updated frequency table X'Y'.

[0067] Single-bit gate-Rabi frequency self-calibration: Step 3.10: Using the updated frequency table X'Y', scan the interaction time of the 795nm Raman light 201 to obtain single-bit Gate Rabi oscillations. Fit each atom independently using a damped sine function to obtain new... Pulse timer w', The pulse timetable w' includes a single-bit gate implemented for each atom. The time required for the flip to occur.

[0068] In this embodiment, the self-calibration of the ORMD waveform and ORMD phase, the self-calibration of the two-bit gate fidelity, and the self-calibration of the addressing single-bit gate fidelity are all relatively independent and can be executed sequentially or separately.

[0069] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0070] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0071] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0072] It should be noted that the embodiments described in this invention are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains can make various modifications or additions to the described embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A method for automatically calibrating the fidelity of logic gates based on a neutral atom quantum computing system, characterized in that, Includes the following steps: Step 1: Two-bit gate fidelity self-calibration; Step 2: Self-calibration of ORMD waveform and ORMD phase; Step 3: Addressing single-bit gate fidelity self-calibration; The two-bit gate fidelity self-calibration in step 1 includes 420nm laser pointing self-calibration, 1013nm laser pointing self-calibration, Rydberg excitation Rabi frequency self-calibration, and single-photon Rabi frequency self-calibration. The addressing single-bit gate fidelity self-calibration in step 3 includes 795nm Raman beam pointing self-calibration and single-bit gate Rabi frequency self-calibration.

2. The method for automatically calibrating the fidelity of logic gates based on a neutral atom quantum computing system according to claim 1, characterized in that, The self-calibration of the ORMD waveform and ORMD phase specifically includes the following steps: Set the iteration count n1 of the ORMD waveform and the iteration count n2 of the ORMD phase, and initialize them to 0 respectively. Set the waveform threshold. Phase threshold Iteration coefficients The interval time t; Step 2.1: After time t, proceed to step 2.2 to perform ORMD waveform verification; Step 2.2, ORMD waveform verification: Acquire the actual ORMD waveform and calculate the difference between the actual ORMD waveform and the target ORMD waveform. , the difference With waveform threshold Compare: like If n2 > 0, then cancel the pause, resume the experiment, and jump to step 2.1; like If n2 = 0, then proceed to step 2.4; like Since n1=n2=0, pause the experiment and jump to step 2.3; like If n1 or n2 > 0, proceed directly to step 2.3; Step 2.3, ORMD waveform calibration: Add an ORMD waveform calibration layer to the driving waveform generated by the arbitrary waveform generator (304). Generate a new driving waveform, and set n1 = n1 + 1, then jump to step 2.2; Step 2.4, ORMD Phase Verification: Acquire the actual ORMD phase and calculate the difference between the actual ORMD phase and the target ORMD phase. , the difference With phase threshold Compare: like If n1 > 0, then cancel the pause, resume the experiment, and jump to step 2.1; like And if n1=n2=0, then there is no operation and the process jumps to step 2.1; like If n1=0 and n2>0, then proceed to step 2.2; like Since n1=n2=0, pause the experiment and jump to step 2.5; like If n1 or n2 > 0, proceed directly to step 2.5; Step 2.5, ORMD Phase Calibration: Add a phase adjustment to the driving waveform. Generate a new driving waveform and set n2=n2+1, then jump to step 2.

4.

3. The method for automatically calibrating the fidelity of logic gates based on a neutral atom quantum computing system according to claim 1, characterized in that, The 420nm laser pointing self-calibration specifically includes the following steps: Step 1.1: Turn on the 420nm laser (203) switch to cause the atoms to produce a light frequency shift; set the count n3=m3=0, calibrate the target row number T in the atom array, and adjust the calibration accuracy. Set threshold T3 and control coefficient. ; Step 1.2: Scan the microwave frequency to obtain the global microwave reversal absorption peak. Average the data for each row and perform Gaussian fitting with the microwave frequency as the horizontal axis to obtain the center frequency value of the absorption peak. Then, perform a second Gaussian fitting with the center frequency values ​​of the absorption peaks of all rows of data and the row number as the horizontal axis. The row number corresponding to the peak value after the second Gaussian fitting is the center value u1. The center value u1 is the atomic row number corresponding to the laser center. Calculate the difference. = (u1-T); If fitting fails, pause the experiment and issue an alarm; Step 1.3: Compare the differences Is it less than the threshold T3? If the difference is... If the voltage is less than the threshold T3, proceed to step 1.4; otherwise, adjust the output of the voltage controller (305) to adjust the Y-axis voltage of the second electrically controlled reflector (126) of the 420nm laser (203). Then proceed to step 1.2; Step 1.

4. Calculate the Gaussian amplitude An1 obtained from the second Gaussian fitting in Step 1.

2. If An1 ≥ An1-1 and m3 = 0, or n3 = 0, then adjust the X-axis voltage of the second electro-control mirror (126) of the 420 nm laser (203). , set n3 = n3 + 1, and jump to Step 1.2; if An1 < An1-1, then , and adjust the X-axis voltage of the second electro-control mirror (126) of the 420 nm laser (203). , set n3 = n3 + 1, m3 = m3 + 1, and jump to Step 1.2; if An1 < An1-1 and m3 > 0, then adjust the X-axis voltage of the second electro-control mirror (126) of the 420 nm laser (203). , and jump to Step 1.5 for self-calibration of the 1013 nm laser pointing. Where An1 is the Gaussian amplitude obtained by the second Gaussian fitting when executing step 1.2 this time, and An1-1 is the Gaussian amplitude obtained by the second Gaussian fitting when executing step 1.2 last time; The 1013nm laser pointing self-calibration specifically includes the following steps: Step 1.5: Turn on the 1013nm laser (202) switch to cause a light frequency shift in the atoms; set the count n4=m4=0, calibrate the target row number T, and adjust the calibration accuracy. Set threshold T4, control coefficient ; Step 1.6: Scan the microwave frequency to obtain the global microwave reversal absorption peak. After averaging the data for each row, perform Gaussian fitting with the microwave frequency as the horizontal axis to obtain the center frequency value of the absorption peak. Then, perform a second Gaussian fitting with the center frequency values ​​of the absorption peaks of all data, using the row number as the horizontal axis. The row number corresponding to the peak value after the second Gaussian fitting is taken as the center value u2, and the difference is calculated. = (u2-T); If fitting fails, pause the experiment and issue an alarm; Step 1.7: Compare the differences Is it less than the threshold T4? If the difference is... If the voltage is less than the threshold T4, proceed to step 1.8; otherwise, adjust the output of the voltage controller (305) to adjust the Y-axis voltage of the first electrically controlled reflector (109) of the 1013nm laser (202). Then proceed to step 1.6; Step 1.

8. Calculate the Gaussian amplitude An2 obtained from the second Gaussian fitting in Step 1.

6. If An2 ≥ An2-1 and m4 = 0, or n4 = 0, then adjust the X-axis voltage of the first electro-control mirror (109) of the 1013 nm laser (202). , set n4 = n4 + 1, and jump to Step 1.6; if An2 < An2-1, then , adjust the X-axis voltage of the first electro-control mirror (109) of the 1013 nm laser (202) , set n4 = n4 + 1, m4 = m4 + 1, and jump to Step 1.6; if An2 < An2-1 and m4 > 0, then adjust the X-axis voltage of the first electro-control mirror (109) of the 1013 nm laser (202) , and jump to Step 1.9 for Rydberg excitation Rabi frequency self-calibration. Where An2 is the Gaussian amplitude obtained by the second Gaussian fitting when executing step 1.6 this time, and An2-1 is the Gaussian amplitude obtained by the second Gaussian fitting when executing step 1.6 last time.

4. The method for automatically calibrating the fidelity of logic gates based on a neutral atom quantum computing system according to claim 1, characterized in that, The Rydberg excitation Rabi frequency self-calibration specifically includes the following steps: Step 1.9: Set the target rabi frequency Set a threshold t1 and a control coefficient. The number of single-photon Rabi frequency scans is n5, and the scan step size is s; Step 1.10: Scan the frequency of the 1013nm laser (202) during Rydberg excitation and obtain the center frequency value u3 of the absorption peak by fitting with a Gaussian function; Step 1.11: Fix the center frequency value u3, scan the action time of the 420nm laser (203), and obtain the Rabi oscillation by fitting with a damped sine function. Pulse time If the fitting fails, the experiment is paused and an alarm is triggered; if the fitting is successful, the voltage locked by the power stabilization PID controller (306) to the 420nm laser (203) is read, and the voltages of the power detector (111) and the ORMD waveform detector (127) are read. Step 1.12: Calculate the difference Compare the differences Does it exceed the threshold t1? If the difference is... If the threshold t1 is exceeded, the lockout voltage of the PID controller (306) for power stabilization of the 420nm laser (203) will be adjusted. If the result is negative, proceed to step 1.10; otherwise, proceed to step 1.13 to perform single-photon Rabi frequency self-calibration.

5. The method for automatically calibrating the fidelity of logic gates based on a neutral atom quantum computing system according to claim 4, characterized in that, The single-photon Rabi frequency self-calibration specifically includes the following steps: Step 1.13: Perform Rydberg excitation and scan the frequency of the 1013nm laser (202) to obtain the actual evolution waveforms of single atoms and diatoms with the frequency of the 1013nm laser (202). Step 1.14: Calculate the difference D between the actual evolution waveform and the theoretical evolution waveform, adjust the locking voltage s of the 420nm laser (203) by the power stabilization PID controller (306), adjust the locking voltage -s of the 1013nm laser (202) by the power stabilization PID controller (306), and jump to step 1.10; until the number of times n5 is reached, jump to step 1.15; Step 1.15: Fit the difference D as the vertical axis and the locking voltage of the power-stabilized PID controller (306) for the 420nm laser (203) as the horizontal axis. Find the lowest point as the optimal point of two-bit gate fidelity. Feed back the locking voltage of the power-stabilized PID controller (306) for the 420nm laser (203) and the locking voltage of the power-stabilized PID controller (306) for the 1013nm laser (202) to the main control computer (301) corresponding to the optimal point of two-bit gate fidelity. The calibration is completed.

6. The method for automatically calibrating the fidelity of logic gates based on a neutral atom quantum computing system according to claim 1, characterized in that, The 795nm Raman beam pointing self-calibration specifically includes the following steps: Step 3.1: Set the X-axis frequency scanning range: Initial position X0 of the X-axis frequency, precision ΔX, number of scans nx, current number of scans is recorded as n6, initialize n6=0; update the X-axis frequency X=X+X0; Step 3.2: Scan the 795nm Raman light (201) interaction time to obtain single-bit Gate Rabi oscillations. Each atom is independently fitted using a damped sine function to obtain the corresponding oscillation for each atom. Pulse duration w2; Step 3.3: Update the X-axis frequency X = X + ΔX, n6 = n6 + 1, jump to step 3.2, until n6 = nx; Step 3.4: Summarize the results For pulse time w2, with the corresponding X-axis frequency as the horizontal axis, perform Gaussian fitting to obtain the center X-axis frequency value X' of the absorption peak of the Gaussian fitting, and update the X-axis frequency X = center X-axis frequency value X'; if the fitting fails, jump to step 3.1 to reset the X-axis frequency scanning range. Step 3.5: Set the Y-axis frequency scanning range: Initial position Y0 for scanning Y-axis frequency, precision ΔY, number of scans ny, current number of scans is recorded as n7=0; Update Y-axis frequency Y=Y+Y0; Step 3.6: Scan the 795nm Raman light (201) interaction time to obtain single-bit Gate Rabi oscillations. Each atom is independently fitted using a damped sine function to obtain... Pulse duration w3; Step 3.7: Update the Y-axis frequency Y = Y + ΔY, n7 = n7 + 1, jump to step 3.6, until n7 = ny; Step 3.8: Summarize the results For pulse time w3, with the corresponding Y-axis frequency as the horizontal axis, perform Gaussian fitting to obtain the center Y-axis frequency value Y' of the absorption peak of the Gaussian fitting, and update the Y-axis frequency Y = center Y-axis frequency value Y'; if the fitting fails, jump to step 3.5 to reset the Y-axis frequency scanning range. Step 3.9: Simultaneously perform steps 3.1 to 3.8 to address all atoms in the atomic array to construct the updated frequency table X'Y'; The single-bit gate-Labbi frequency self-calibration specifically includes the following steps: Step 3.10: Using the updated frequency table X'Y', scan the interaction time of the 795nm Raman light (201) to obtain the single-bit Gate Rabi oscillation. Fit each atom independently using a damped sine function to obtain new... Pulse timetable w'.

7. An automatically calibrated logic gate based on a neutral atom quantum computing system, comprising a 420nm laser system and an atom array, characterized in that, It also includes a monitoring system, which includes an oscilloscope (309) and a central control computer (301). The 420nm laser system includes a 420nm laser (203), a delayed beat frequency optical module, a target ORMD waveform generation module, a target ORMD phase monitoring module, and an actual ORMD waveform phase analysis module. The delayed beat frequency optical module includes a first collimator (114), an optical fiber, and a second collimator (121). The 420nm laser (203) passes sequentially through a first half-wave plate (112) and a first polarizing beam splitter (113). One of the 420nm laser beams (203) after being split by the first polarizing beam splitter (113) is used as the delayed beat frequency light (204) and passes sequentially through the first collimator (114), the optical fiber, the second collimator (121), the fourth half-wave plate (122), and the beam splitter (120). The target ORMD waveform generation module includes an acousto-optic modulator (117) and an arbitrary waveform generator (304). Another 420nm laser (203) after being split by the first polarization beam splitter (113) passes through the second half-wave plate (115) and the second polarization beam splitter (116) in sequence. One of the 420nm laser beams (203) after being split by the second polarization beam splitter (116) is input to the acousto-optic modulator (117), and the acousto-optic modulator (117) outputs the 420nm laser (203) of the target ORMD waveform. The acousto-optic modulator (117) is connected to the arbitrary waveform generator (304). The arbitrary waveform generator (304) outputs a driving waveform to the acousto-optic modulator (117). The central control computer (301) drives the generation of the target ORMD waveform by adjusting the amplitude and phase of the driving waveform output by the arbitrary waveform generator (304). The target ORMD phase detection module includes an ORMD phase detector (123) and a high-bandwidth oscilloscope (302). One of the beams of the 420nm laser (203) of the target ORMD waveform after being split by the first beam splitter (118) passes through the third half-wave plate (119) and the beam splitter prism (120) in sequence. After being combined with the delayed beat frequency light (204) by the beam splitter prism (120), it passes through the ORMD phase detector (123), the high-bandwidth oscilloscope (302), and the central control computer (301) in sequence. The central control computer (301) obtains the target ORMD phase. The actual ORMD waveform phase analysis module includes a second electrically controlled mirror (126), a voltage controller (305), and an ORMD waveform detector (127). Another 420nm laser beam of the target ORMD waveform (203) after passing through the first beam splitter (118) passes through the second beam splitter (124) and the second electrically controlled mirror (126) and enters the atomic array. After passing through the atomic array, the 420nm laser (203) passes through the ORMD waveform detector (127), the high-bandwidth oscilloscope (302), and the central control computer (301). The central control computer (301) analyzes and obtains the actual ORMD waveform and the actual ORMD phase. The second electrically controlled reflector (126) is connected to the voltage controller (305), and the voltage controller (305) is connected to the main control computer (301). The main control computer (301) changes the angle at which the 420nm laser (203) is incident on the atomic array by changing the magnitude of the voltage signal output from the voltage controller (305) to the second electrically controlled reflector (126).

8. The automatic calibration logic gate for a neutral atom quantum computing system according to claim 7, characterized in that, It also includes a 795nm Raman optical system and a 1013nm laser system; The 795nm Raman optical system also includes a 795nm Raman beam (201) and an addressable single-bit gate module. The addressable single-bit gate module includes a two-dimensional acousto-optic deflector (102) and an arbitrary waveform generator (304). The 795nm Raman beam (201) is split by a third beam splitter (101), and one beam of 795nm Raman beam (201) enters the two-dimensional acousto-optic deflector (102). The two-dimensional acousto-optic deflector (102) outputs 795nm Raman beam (201). The diffracted light of 201 is directed to the atomic array; the two-dimensional acousto-optic deflector (102) is connected to the arbitrary waveform generator (304), the arbitrary waveform generator (304) is connected to the central control computer (301), the central control computer (301) controls the arbitrary waveform generator (304) to output radio frequency signals to the two-dimensional acousto-optic deflector (102), and the central control computer (301) adjusts the intensity and angle of the diffracted light of 795nm Raman light (201) by changing the amplitude and frequency of the radio frequency signal; The 1013nm laser system includes a 1013nm laser (202) and a two-bit gate operation module. The two-bit gate operation module includes a first electrically controlled mirror (109), a power detector (111), and a voltage controller (305). The 1013nm laser (202) passes sequentially through a fifth half-wave plate (104), a third polarization beam splitter (105), and a fourth beam splitter (108). One of the 1013nm laser beams (202) split by the fourth beam splitter (108) is reflected by the first electrically controlled mirror (109) and enters the atomic array. After passing through the atomic array, the 1013nm laser (202) enters the power detector (111). The output signal of the power detector (111) is output to the oscilloscope (309) and transmitted to the central control computer (301). The first electrically controlled reflector (109) is connected to the voltage controller (305). The central control computer (301) changes the angle at which the 1013nm laser (202) is incident on the atomic array by changing the magnitude of the voltage signal output from the voltage controller (305) to the first electrically controlled reflector (109).

9. The automatic calibration logic gate for a neutral atom quantum computing system according to claim 8, characterized in that, It also includes a 795nm Raman optical system, a 1013nm laser system, and a 420nm laser system, all of which include power stabilization and monitoring modules; In the power stabilization and monitoring module of the 795nm Raman optical system, another 795nm Raman beam (201) split by the third beam splitter (101) passes through the first power stabilization detector (103) and the power stabilization PID controller (306) in sequence. The power stabilization PID controller (306) outputs an error monitoring signal to the oscilloscope (309) and transmits it to the central control computer (301). In the power stabilization and monitoring module of the 1013nm laser system, another 1013nm laser (202) split by the fourth beam splitter (108) passes through the second power stabilization detector (110) and the power stabilization PID controller (306) in sequence. The power stabilization PID controller (306) outputs the power stabilization monitoring signal of the 1013nm laser (202) to the oscilloscope (309) and transmits it to the central control computer (301). In the power stabilization and monitoring module of the 420nm laser system, one of the 420nm laser beams (203) with the target ORMD waveform split by the second beam splitter (124) enters the second electronically controlled reflector (126), and the other 420nm laser beam (203) with the target ORMD waveform passes through the third power stabilization detector (125) and the power stabilization PID controller (306) in sequence. The power stabilization PID controller (306) outputs the power stabilization monitoring signal of the 420nm laser (203) to the oscilloscope (309) and transmits it to the central control computer (301). The 1013nm laser system and the 420nm laser system also include a frequency locking and monitoring module, which includes an electro-optic modulator (106), an ultra-stable cavity (107), and a frequency-locked PID controller (307). In the 1013nm laser system, one of the 1013nm laser beams (202) split by the third polarization beam splitter (105) passes through an electro-optic modulator (106), an ultra-stable cavity (107), and a frequency-locked PID controller (307) for frequency locking. The frequency-locked PID controller (307) also outputs a frequency-locked monitoring signal for the 1013nm laser (202) and transmits it to the central control computer (301). One of the 1013nm laser beams (202) split by the third polarization beam splitter (105) enters the fourth beam splitter (108). The electro-optic modulator (106) is connected to the microwave source (303), and the microwave source (303) is connected to the central control computer (301). The central control computer (301) adjusts the frequency of the radio frequency signal input from the microwave source (303) to the electro-optic modulator (106) according to the monitoring signal to adjust the frequency shift of the electro-optic modulator (106). In the 420nm laser system, the other 420nm laser (203) after being split by the second polarization beam splitter (116) passes through the ultra-stable cavity (107) and the frequency-locked PID controller (307) in sequence for frequency locking. The frequency-locked PID controller (307) also outputs a frequency locking monitoring signal for the 420nm laser (203) and transmits it to the central control computer (301).

10. The automatic calibration logic gate for a neutral atom-based quantum computing system according to claim 9, characterized in that, It also includes a microwave speaker (128), a fluxgate meter (308), and a thermometer (310). The microwave speaker (128) is connected to a microwave source (303), the fluxgate meter (308) is connected to an oscilloscope (309), and the thermometer (310) is connected to a central control computer (301).

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