Compensation microwave generation method and correction method for quantum bit crosstalk correction

Abstract

The present application provides a compensating microwave generation method and a microwave crosstalk correction method for quantum bit crosstalk correction. The generation method comprises the following steps: calibrating a quantum bit to be calibrated to obtain a quantum bit to be calibrated, wherein at least one quantum bit to be corrected causes crosstalk to the quantum bit to be calibrated; when a microwave pulse sequence is applied to any quantum bit to be corrected to form a quantum bit to be calibrated, a microwave control line is used as a target control line, and a microwave pulse sequence is applied to the target control line to sample and measure the probability of a target state in the quantum bit to be calibrated; determining at least one target peak based on a 1-state probability change diagram; and generating crosstalk intensity information of the quantum bit to be corrected that causes crosstalk to the quantum bit to be calibrated according to microwave pulse time, microwave parameters and a crosstalk calculation formula, so as to generate compensating microwaves according to the crosstalk intensity information.

Description

Technical Field

[0001] The present application relates to the field of quantum computing technology, and more specifically, to a compensating microwave generation method and a microwave crosstalk correction method for quantum bit crosstalk correction. Background Art

[0002] Universal quantum computing has attracted much attention due to its potential powerful computing power. To realize universal quantum computing, high-fidelity quantum gates are essential. In superconducting quantum computing, the distance between bits is small, and the control lines of the inner bits may need to pass through the outer bits to connect to the outside. Therefore, when microwave signals are input, the insulation failure of the control lines, the end of the control lines is too close to other bits, and the binding lines between the sample box and the samples will cause crosstalk between the control lines. When different bits are manipulated in parallel, the microwave signals from other bits will affect the fidelity of the quantum gate. Since most of the above structures are in the dilution refrigerator when the quantum computer is running, it is impossible to use the measurement and analysis methods in the field of traditional microwave engineering (such as vector network analyzers) to measure and compensate for the crosstalk signal. Summary of the invention

[0003] In view of this, the present application provides a compensating microwave generation method and a microwave crosstalk correction method for quantum bit crosstalk correction.

[0004] One aspect of the present application provides a compensating microwave generation method for quantum bit crosstalk correction, comprising:

[0005] Calibrate the quantum bit to be calibrated to obtain the quantum bit to be calibrated, wherein the quantum bit to be calibrated includes a target gate, different state marks and a bit frequency, and at least one quantum bit to be corrected causes crosstalk to the quantum bit to be calibrated;

[0006] When a microwave pulse sequence is applied to any of the above-mentioned quantum bits to be corrected to form the above-mentioned quantum bits to be calibrated, the microwave control line is used as the target control line, and a microwave pulse sequence is applied to the above-mentioned target control line to sample and measure the probability of the target state in the above-mentioned quantum bits to be calibrated, wherein the phase difference between two adjacent pulses in the above-mentioned microwave pulse sequence is a preset value, and the above-mentioned microwave pulse sequence has a microwave source frequency;

[0007] Determine at least one target peak based on a 1-state probability variation diagram, wherein the 1-state probability variation diagram is generated according to the probability obtained by sampling, and the target peak includes a microwave pulse time and a microwave parameter corresponding to the microwave pulse time;

[0008] According to the microwave pulse time, the microwave parameters and the crosstalk calculation formula, the crosstalk intensity information of the crosstalk caused by the quantum bit to be corrected to the quantum bit to be calibrated is generated, so as to generate the compensation microwave according to the crosstalk intensity information.

[0009] According to an embodiment of the present application, the microwave parameters include a frequency offset corresponding to the microwave pulse time, or phase information and a microwave frequency difference corresponding to the microwave pulse time.

[0010] According to an embodiment of the present application, based on the microwave pulse time, the microwave parameters and the crosstalk calculation formula, the crosstalk intensity information of the crosstalk caused by the qubit to be calibrated to the qubit to be corrected is generated, including:

[0011] Based on the first crosstalk calculation formula, the crosstalk intensity information is generated according to the microwave pulse time and the frequency offset; or

[0012] Based on the second crosstalk calculation formula, the crosstalk intensity information is generated according to the microwave pulse time, the phase information and the microwave frequency difference.

[0013] According to an embodiment of the present application, based on the second crosstalk calculation formula, the crosstalk intensity information is generated according to the microwave pulse time, the phase information and the microwave frequency difference, including:

[0014] Performing fitting processing on the microwave pulse time corresponding to each of the target peaks and the phase information to obtain a linear fitting function;

[0015] Determine a target pulse time at a target phase according to the linear fitting function;

[0016] Based on the second crosstalk calculation formula, the crosstalk intensity information is generated according to the target pulse time and the microwave frequency difference.

[0017] According to an embodiment of the present application, the first crosstalk calculation formula is shown in formula (1), and the second crosstalk calculation formula is shown in formula (2):

[0018] (1)

[0019] (2)

[0020] in, is the microwave pulse time, is the microwave frequency difference, is the frequency offset, Indicates that the target peak is from the sampling time The first few peaks, for the i-th target peak, , is the crosstalk strength information, is the target pulse time.

[0021] According to an embodiment of the present application, applying a microwave pulse sequence on the target control line to sample and measure the probability of the target state in the qubit to be calibrated and the qubit to be corrected includes:

[0022] Acquire the above microwave pulse sequence, wherein the above microwave pulse sequence includes pulses, the duration of each of the above pulses is a scanning variable;

[0023] Applying the microwave pulse sequence to the target control line to sample and measure the probability of the target state in the qubit to be calibrated and the qubit to be corrected;

[0024] When the target peak cannot be determined on the 1-state probability variation diagram corresponding to the probability obtained by the above measurement, the microwave pulse sequence or microwave parameters are adjusted to perform sampling measurement using the adjusted microwave pulse sequence or the adjusted microwave parameters.

[0025] According to an embodiment of the present application, the microwave pulse sequence or microwave parameters are adjusted to perform sampling measurement using the adjusted microwave pulse sequence or the adjusted microwave parameters, including:

[0026] Adjusting the frequency of the pulses in the microwave pulse sequence to iteratively perform sampling measurement using the adjusted microwave pulse sequence; or

[0027] The phase of the pulses in the microwave pulse sequence is adjusted so as to iteratively use the adjusted microwave pulse sequence for sampling measurement.

[0028] According to an embodiment of the present application, the above method further includes:

[0029] When the quantum bit to be corrected acts on the control line to be calibrated, the compensating microwave is loaded on the control line to be calibrated;

[0030] Under the condition that the first parameter of the compensating microwave on the control line to be calibrated is fixed, the second parameter of the compensating microwave is changed to determine the phase information and amplitude information of the compensating microwave according to the 1-state probability change diagram corresponding to the second parameter, so as to generate the final compensating microwave according to the crosstalk intensity information, the phase information and the amplitude information.

[0031] According to an embodiment of the present application, the first parameter and the second parameter both include microwave amplitude or microwave phase;

[0032] Wherein, in the case of fixing the first parameter of the compensating microwave on the control line to be calibrated, changing the second parameter of the compensating microwave to determine the phase information and amplitude information of the compensating microwave according to the 1-state probability change diagram corresponding to the second parameter, comprises:

[0033] Under the condition that the microwave amplitude is fixed, the microwave phase is changed to determine a first 1-state probability change diagram according to the changed microwave phase, wherein the first 1-state probability change diagram has a first symmetry axis;

[0034] Determine the phase information according to the first symmetry axis;

[0035] Under the condition that the microwave phase is fixed, the microwave amplitude is changed to determine a second 1-state probability change diagram according to the changed microwave amplitude, wherein the second 1-state probability change diagram has a second symmetry axis;

[0036] The amplitude information is determined according to the second symmetry axis.

[0037] Another aspect of the present application provides a microwave crosstalk correction method for quantum bits, comprising:

[0038] Selecting a first microwave control line and at least one second microwave control line respectively, wherein the first microwave control line is used as a microwave source for a first quantum bit, and one of the second microwave control lines is used as a microwave source for a second quantum bit;

[0039] Applying a compensating microwave corresponding to the first qubit to the second microwave control line to correct the crosstalk caused by the first qubit to the second microwave control line; and / or

[0040] Exchange or change different microwave control lines into the first microwave control line and the second microwave control line, that is, the second microwave control line of a first quantum bit can be used as the second microwave control line of other first quantum bits, and the control line can also be used as the first control line, and use at least one control line of the quantum bit to be corrected as the second microwave control line.

[0041] According to an embodiment of the present application, the quantum bit to be calibrated is obtained by calibrating the quantum bit to be calibrated, and a microwave pulse sequence is applied to the microwave control line of the initial quantum bit to determine at least one target peak from the 1-state probability change diagram obtained by sampling and measuring the probability of the target state in the quantum bit to be calibrated, thereby calculating the crosstalk intensity information of the crosstalk caused by the quantum bit to be corrected on the quantum bit to be calibrated according to the parameters of the target peak combined with the crosstalk calculation formula, thereby generating compensation microwaves according to the crosstalk intensity information. The compensation microwave generation method of the present application has low computational complexity and good signal-to-noise ratio, and can effectively eliminate the influence of crosstalk in the quantum bit on the gate fidelity. At the same time, since the above-mentioned quantum bits to be calibrated do not affect each other, the crosstalk intensity information and compensation microwaves of the same quantum bit to be calibrated on different quantum bits to be calibrated can be calibrated and calculated in parallel. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The above and other objects, features and advantages of the present application will become more apparent through the following description of the embodiments of the present application with reference to the accompanying drawings, in which:

[0043] Figure 1 A flow chart of a method for generating compensating microwaves according to an embodiment of the present application is shown;

[0044] Figure 2 A schematic diagram of a microwave pulse sequence according to an embodiment of the present application is shown;

[0045] Figure 3 A schematic diagram showing the evolution of a quantum state on a Block sphere according to an embodiment of the present application is shown;

[0046] Figure 4 A 1-state probability change diagram according to an embodiment of the present application is shown;

[0047] Figure 5 shows a 1-state probability change diagram according to another embodiment of the present application;

[0048] Figure 6 A linear fitting schematic diagram according to an embodiment of the present application is shown;

[0049] Figure 7 A linear fitting schematic diagram according to another embodiment of the present application is shown;

[0050] Figure 8 A schematic diagram showing the measured relationship between frequency and duration changes according to an embodiment of the present application is shown;

[0051] Fig. 9 A schematic diagram showing the measured relationship between frequency and duration changes according to another embodiment of the present application is shown;

[0052] FIG. 10( a ) shows that the number of microwave pulses according to an embodiment of the present application is Schematic diagram of the relationship between the target state probability and the compensation microwave amplitude and phase;

[0053] FIG. 10( b ) shows that the number of microwave pulses according to an embodiment of the present application is Schematic diagram of the relationship between the target state probability and the compensation microwave amplitude and phase;

[0054] FIG. 10( c ) shows that the number of microwave pulses according to an embodiment of the present application is Schematic diagram of the relationship between the target state probability and the compensation microwave amplitude and phase;

[0055] FIG. 11( a ) shows an experimental diagram of a microwave phase one-iteration scanning according to an embodiment of the present application;

[0056] FIG11( b ) shows an experimental diagram of a first iterative scan of microwave amplitude according to an embodiment of the present application;

[0057] FIG11( c ) shows an experimental diagram of two iterative scans of microwave amplitude according to an embodiment of the present application;

[0058] FIG11( d ) shows an experimental diagram of two iterative scanning of the microwave phase according to an embodiment of the present application;

[0059] FIG. 12 ( a ) is a schematic diagram showing the difference between a single-bit gate XEB before and after correction in a serial test according to an embodiment of the present application;

[0060] FIG. 12 ( b ) is a schematic diagram showing the difference between a single-bit gate XEB before and after correction in a parallel test according to an embodiment of the present application;

[0061] FIG12( c ) shows a schematic diagram of a control experiment of a single-bit gate XEB before and after correction in a parallel test according to an embodiment of the present application. DETAILED DESCRIPTION

[0062] Below, embodiments of the present application will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present application. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present application. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present application.

[0063] The terms used herein are only for describing specific embodiments and are not intended to limit the present application. The terms "include", "comprising", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0064] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0065] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0066] Since qubits are extremely sensitive to microwave noise, they can be used to detect crosstalk between microwave signal lines. There are currently many methods to test this crosstalk signal, such as:

[0067] A microwave pulse of another bit frequency is input on a microwave control line, and the crosstalk intensity is estimated by testing the target bit resonance Rabi period. However, this method cannot obtain the phase information of the crosstalk, and can only test the crosstalk intensity near the target bit frequency. However, when the subsequent bits are used normally, the pulse frequency input on the microwave control line is generally much different from the target bit frequency, so this solution cannot effectively provide accurate microwave crosstalk intensity information.

[0068] A microwave pulse of its own bit frequency is input on a microwave control line, and the crosstalk strength of the control line is calculated by testing the target Rabi period and combining the two-bit frequency difference. This method can ensure that the crosstalk strength information obtained by the test is the crosstalk strength information used in subsequent experiments, but because the amplitude of the detuned Rabi signal is very small, it is generally difficult to obtain a result with high enough fidelity; and this method cannot effectively obtain the phase information of the crosstalk signal, so it is impossible to compensate for the crosstalk noise.

[0069] A microwave pulse of its own bit frequency is input on a microwave control line, and a low-frequency pulse is compensated on the z control line of the target bit at the same time, and then the amplitude information of the crosstalk signal is obtained by calculating the measurement results. However, this method requires the use of multiple microwave sources, and in order to avoid the applied compensation pulse affecting other bits during the test, it is necessary to perform serial measurements when the crosstalk between different control lines is unclear; and the subsequent processing of the measurement results requires multiple reference system transformations, and the data processing is relatively complicated.

[0070] Instead of correcting the specific crosstalk intensity between microwave control lines, the adjustment is made so that there is an interval between bits f01, and then only the effect of microwaves of other bits on the energy level transition between the 1 state and the 2 state of the target bit during the microwave parallel input is corrected. The specific operation method is to apply a series of Pi-pulse microwaves in parallel to all bits, and measure the probability of the 2 state of each bit after the microwave sequence ends. By scanning the intervals of different microwaves in the above microwave sequence, the probability of the 2 state reaches a maximum value. At this time, the microwave interval can cascade amplify the microwave crosstalk effect between bits. At this time, the microwave interval is fixed, and the specific bit that has an impact on it is scanned, and the intensity and phase of the compensation microwave are scanned on the target bit to compensate for the impact of the crosstalk. This scheme can obtain the crosstalk information between bits within O (number of bits n) measurements, and only microwave correction is required for the bit pairs with larger crosstalk, and the impact of microwave crosstalk can be effectively corrected without additional measurements and complex calculations. However, this solution can only offset the impact of microwave crosstalk signals on the energy level transition between state 1 and state 2 of the target bit, and cannot measure the specific size and amplitude of the crosstalk microwave. Once the bit operating point needs to be adjusted subsequently, the entire system needs to be remeasured and corrected.

[0071] In summary, the existing microwave solutions either cannot test the microwave crosstalk intensity and phase information at the operating point frequency, or are limited by the detuned Rabi and cannot obtain sufficient fidelity, or require complex microwave input methods and calculation methods, or need to use other methods to circumvent the measurement problem of microwave crosstalk intensity information. There is currently no fast, effective, high-fidelity microwave crosstalk signal amplitude and phase measurement and calibration technology.

[0072] In view of this, the present disclosure provides a compensating microwave generation method and a microwave crosstalk correction method for quantum bit crosstalk correction, the generation method comprising calibrating a quantum bit to be calibrated to obtain a quantum bit to be calibrated, wherein the quantum bit to be calibrated includes a target gate, different state marks and a bit frequency, and at least one quantum bit to be corrected causes crosstalk to the quantum bit to be calibrated; when a microwave pulse sequence is applied to any quantum bit to be corrected to form a quantum bit to be calibrated, a microwave control line is used as a target control line, and a microwave pulse sequence is applied to the target control line to sample and measure the probability of a target state in the quantum bit to be calibrated, wherein the phase difference between two adjacent pulses in the microwave pulse sequence is a preset value, and the microwave pulse sequence has a microwave source frequency; at least one target peak is determined based on a 1-state probability change diagram, wherein the 1-state probability change diagram is generated according to the probability obtained by sampling, and the target peak includes a microwave pulse time and a microwave parameter corresponding to the microwave pulse time; according to the microwave pulse time, the microwave parameter and the crosstalk calculation formula, crosstalk intensity information of the quantum bit to be corrected that causes crosstalk to the quantum bit to be calibrated is generated, so as to generate a compensating microwave according to the crosstalk intensity information.

[0073] In the embodiments of this application, the collection, updating, analysis, processing, use, transmission, provision, disclosure, storage, etc. of the data involved (for example, including but not limited to user personal information) are in compliance with the provisions of relevant laws and regulations, are used for legitimate purposes, and do not violate public order and good morals. In particular, necessary measures are taken for user personal information to prevent illegal access to user personal information data and maintain the security of user personal information and network security.

[0074] Figure 1 A flow chart of a compensating microwave generating method according to an embodiment of the present application is shown. Figure 2 A schematic diagram of a microwave pulse sequence according to an embodiment of the present application is shown. Figure 3 A schematic diagram of the evolution of a quantum state on a Block sphere according to an embodiment of the present application is shown.

[0075] like Figure 1 As shown, the compensating microwave generation method for quantum bit crosstalk correction includes operations S101 to S104.

[0076] In operation S101, a calibration process is performed on the quantum bit to be calibrated to obtain the quantum bit to be calibrated, wherein the quantum bit to be calibrated includes a target gate, different state marks and a bit frequency, and at least one quantum bit to be corrected causes crosstalk to the quantum bit to be corrected;

[0077] In operation S102, when a microwave pulse sequence is applied to any of the above-mentioned quantum bits to be corrected to form a quantum bit to be calibrated, the microwave control line is used as a target control line, and a microwave pulse sequence is applied to the target control line to sample and measure the probability of a target state in the quantum bit to be calibrated, wherein the phase difference between two adjacent pulses in the microwave pulse sequence is a preset value, and the microwave pulse sequence has a microwave source frequency;

[0078] In operation S103, at least one target peak is determined based on the 1-state probability variation diagram, wherein the 1-state probability variation diagram is generated according to the probability obtained by sampling, and the target peak includes the microwave pulse time and the microwave parameter corresponding to the microwave pulse time;

[0079] In operation S104, crosstalk intensity information of crosstalk caused by the quantum bit to be corrected on the quantum bit to be calibrated is generated according to the microwave pulse time, microwave parameters and the crosstalk calculation formula, so as to generate compensation microwaves according to the crosstalk intensity information.

[0080] According to an embodiment of the present application, the target gate may be an X / 2 gate or other gates, and the state flag may be State and The default value can be , the target state can be State, that is, state 1.

[0081] According to an embodiment of the present application, the X / 2 gate and reading of the quantum bit to be calibrated are calibrated to achieve preliminary control of the quantum bit, thereby obtaining the quantum bit to be calibrated; wherein, the frequency of the quantum bit to be calibrated is calibrated; and the time axes of each control channel of all bits (initial quantum bit, quantum bit to be corrected, quantum bit to be corrected) are preliminarily aligned.

[0082] According to the embodiment of the present application, a microwave control line is selected as the microwave source of the input sample (i.e., the quantum bit to be calibrated), and its microwave frequency is the frequency required for crosstalk measurement, which can be the frequency difference between the quantum bit to be calibrated and the quantum bit to be corrected, or other values ​​set based on experience (i.e., microwave source frequency). For the scenario of bit-in-situ XY control line crosstalk correction, its frequency is the frequency of the bit corresponding to the control line (i.e., the quantum bit to be calibrated described above).

[0083] According to an embodiment of the present application, the microwave control line is applied as follows Figure 2 The microwave pulse sequence shown in the figure has a phase difference between two adjacent pulses. (That is, a pulse sequence consisting of +X / 2 and -X / 2, but its gate duration does not necessarily make the quantum state rotate exactly ,like Figure 3 As shown), the pulse amplitude can be set to any value, the number of pulses is a fixed value, and the duration of each pulse is the scanning variable , and measure the 1-state probability of each bit after the entire microwave sequence ends in parallel, thereby obtaining the 1-state probability change graph.

[0084] Figure 3 The dotted circle in the middle is the circle where the quantum state rotates during each X / 2 gate, and the black solid line is the true trajectory of the quantum state. The microwave pulse sequence is +X / 2, -X / 2 alternating pulses, or The +X / 2 pulse sequence (the rotation around the Z axis is achieved by rotating the Block spherical coordinate system).

[0085] According to an embodiment of the present application, in the above 1-state probability change diagram, for a certain time , there will be a target peak on the microwave source frequency axis, and the corresponding microwave pulse time will be recorded and microwave parameters. Among them, the target peak can be a peak width of about The microwave parameter can be the frequency offset , phase information The microwave frequency difference At least one of the above, wherein the microwave frequency difference is the frequency difference between the microwave source frequency and the quantum bit to be calibrated.

[0086] According to the embodiments of the present application, the crosstalk intensity information of the crosstalk caused by the quantum bit to be corrected to the quantum bit to be calibrated can be calculated according to the microwave pulse time, microwave parameters and the crosstalk calculation formula, so as to generate compensation microwaves according to the crosstalk intensity information.

[0087] According to an embodiment of the present application, the quantum bit to be calibrated is obtained by calibrating the quantum bit to be calibrated, and a microwave pulse sequence is applied to the microwave control line of the initial quantum bit to determine at least one target peak from the 1-state probability change diagram obtained by sampling and measuring the probability of the target state in the quantum bit to be corrected according to the quantum bit to be calibrated, thereby calculating the crosstalk intensity information of the quantum bit to be corrected on the quantum bit to be calibrated according to the parameters of the target peak combined with the crosstalk calculation formula, thereby generating compensation microwaves according to the crosstalk intensity information. The compensation microwave generation method of the present application has low computational complexity and good signal-to-noise ratio, and can effectively eliminate the influence of crosstalk in the quantum bit on the gate fidelity. At the same time, since the above-mentioned quantum bits to be calibrated do not affect each other, the crosstalk intensity information and compensation microwaves of the same quantum bit to be calibrated on different quantum bits to be calibrated can be calibrated and calculated in parallel.

[0088] According to an embodiment of the present application, based on microwave pulse time, microwave parameters and crosstalk calculation formula, crosstalk intensity information of crosstalk caused by the quantum bit to be corrected to the quantum bit to be calibrated is generated, including

[0089] Generate crosstalk intensity information based on the first crosstalk calculation formula according to the microwave pulse time and frequency offset; or

[0090] Based on the second crosstalk calculation formula, crosstalk intensity information is generated according to microwave pulse time, phase information and microwave frequency difference.

[0091] According to an embodiment of the present application, the microwave pulse time and frequency offset of each target peak and the microwave frequency difference Substitute into the first crosstalk calculation formula to calculate the crosstalk strength information , as shown in formula (1):

[0092] (1)

[0093] in, is the microwave pulse time, is the microwave frequency difference, is the frequency offset, Indicates that the target peak is from the sampling time The first few peaks, for the i-th target peak, , It is the crosstalk strength information.

[0094] According to an embodiment of the present application, based on the second crosstalk calculation formula, crosstalk intensity information is generated according to microwave pulse time, phase information and microwave frequency difference, including:

[0095] Fitting the microwave pulse time and phase information corresponding to each target peak to obtain a linear fitting function;

[0096] determining a target pulse time at a target phase according to a linear fitting function;

[0097] Based on the second crosstalk calculation formula, crosstalk intensity information is generated according to the target pulse time and the microwave frequency difference.

[0098] According to an embodiment of the present application, in the above measurement results (i.e., the generated 1-state probability change graph), for certain time , there will be a target peak on the microwave pulse phase axis, and its corresponding microwave pulse time will be recorded and phase information , and then perform linear fitting on the above maximum points to deduce the target phase The corresponding target pulse time , while recording the microwave frequency difference . It should be noted that when the number of pulses When it is large, the peak width of the above target peak will be very thin, so the sampling density needs to be increased accordingly.

[0099] According to the embodiment of the present application, the target pulse time and the microwave frequency difference are substituted into the second crosstalk calculation formula shown in formula (2) to obtain the crosstalk intensity information: .

[0100] (2)

[0101] in, is the target pulse time.

[0102] According to an embodiment of the present application, a microwave pulse sequence is applied to a target control line to sample and measure the probability of a target state in a qubit to be calibrated and a qubit to be corrected, including:

[0103] Acquire a microwave pulse sequence, wherein the microwave pulse sequence includes pulses, the duration of each pulse is the scan variable;

[0104] Applying a microwave pulse sequence to a target control line to sample and measure the probability of a target state in a qubit to be calibrated and a qubit to be corrected;

[0105] When the target peak cannot be determined on the 1-state probability variation diagram corresponding to the measured probability, the microwave pulse sequence or microwave parameters are adjusted to perform sampling measurement using the adjusted microwave pulse sequence or the adjusted microwave parameters.

[0106] According to an embodiment of the present application, adjusting a microwave pulse sequence or a microwave parameter to perform sampling measurement using the adjusted microwave pulse sequence or the adjusted microwave parameter includes:

[0107] Adjusting the frequency of the pulses in the microwave pulse sequence (i.e., the microwave source frequency) to iteratively perform sampling measurement using the adjusted microwave pulse sequence; or

[0108] The phases of pulses in the microwave pulse sequence are adjusted to iteratively perform sampling measurement using the adjusted microwave pulse sequence.

[0109] In the first embodiment, due to the above duration Due to the limitation that the microwave source sampling rate cannot be changed continuously, the pulse frequency can be slightly adjusted to improve the sampling accuracy. Assuming that the bit microwave source sampling rate is , when the inter-bit detuning reaches (i.e., sampling rate ), the accuracy of the microwave source sampling rate results in a detuned Rabi of only Step accuracy.

[0110] According to the embodiment of the present application, due to the different detuning and crosstalk strengths of different bit pairs, the number of pulses corresponding to the optimal signal-to-noise ratio is Generally speaking, they can be selected in order is 2, 8, 32, 128, etc., to obtain a good signal-to-noise ratio for both small detuning and large crosstalk and large detuning and small crosstalk. In addition, if At the beginning, the probability of state 1 increases to 1 and then It gradually decreases, and at the same time, multiple levels of main maximum stripes appear in the image.

[0111] According to the embodiment of the present application, at this time, as long as different bits are divided into microwave input bits for testing, only 4n rounds of measurement are needed at most to obtain the crosstalk intensity information of up to 40dB (or even lower) between all bit pairs, without significantly increasing the number of experiments, and without complex calculations, the crosstalk intensity information between bit pairs can be obtained, where n represents the number of all bits that need to be corrected. And if you want to test the control line crosstalk intensity information of other frequency points, you only need to adjust the frequency of the input microwave (i.e., the microwave source frequency).

[0112] It should be noted that this application is based on the quantum bit to be corrected Treating calibrated qubits If it is necessary to correct certain pairs of bits (for example right ), then the compensation microwave generation method of the present application also needs to be performed for calculation.

[0113] In the first embodiment, due to the above duration Due to the limitation that the microwave source sampling rate cannot be changed continuously, the pulse frequency can be slightly adjusted to improve the sampling accuracy. Assuming that the bit microwave source sampling rate is , when the frequency difference between the microwave source frequency and the frequency of the quantum bit to be calibrated (i.e., the microwave frequency difference) reaches (i.e., sampling rate ), the accuracy of the microwave source sampling rate results in a detuned Rabi of only Step accuracy.

[0114] To further improve accuracy, the frequency offset can be In microwave frequency difference When the frequency offset is slightly changed, the microwave sampling rate The step remains unchanged, but due to the slight change in frequency offset, the final detuned Rabi rotation angle can still be within Sampling is performed in steps of , thereby obtaining a sampling accuracy higher than the microwave source sampling rate.

[0115] In the second embodiment, in order to improve the scanning accuracy and make the measurement result not affected by the microwave source sampling rate, if the microwave source frequency of the target quantum bit is to be strictly limited, the relative phase of two adjacent microwave pulses in the microwave pulse sequence can be modified so that When the phase of the microwave pulse is exactly the same as the angle at which the previous microwave pulse rotates the quantum state on the horizontal plane of the Block ball, it can also produce an amplification effect on the quantum state.

[0116] According to an embodiment of the present application, the compensating microwave generating method further includes:

[0117] When the qubit to be calibrated has a control line, the control line is called the control line to be calibrated and the qubit to be corrected to be calibrated control line, and the compensation microwave is loaded on the control line to be calibrated to offset the influence of the microwave pulse sequence applied on the target control line on the qubit to be corrected, wherein the influence is hereinafter referred to as a crosstalk signal;

[0118] Under the condition that the first parameter of the compensating microwave on the control line to be calibrated is fixed, the second parameter of the compensating microwave is changed to determine the phase information and amplitude information of the compensating microwave according to the 1-state probability change diagram corresponding to the second parameter, so as to generate the final compensating microwave according to the crosstalk intensity information, phase information and amplitude information.

[0119] According to an embodiment of the present application, the first parameter and the second parameter both include microwave amplitude or microwave phase.

[0120] Wherein, in the case of fixing the first parameter of the compensating microwave on the control line to be calibrated, changing the second parameter of the compensating microwave to determine the phase information and amplitude information of the compensating microwave according to the 1-state probability change diagram corresponding to the second parameter includes:

[0121] Under the condition of fixed microwave amplitude, changing the microwave phase to determine a first 1-state probability variation diagram according to the changed microwave phase, wherein the first 1-state probability variation diagram has a first symmetry axis;

[0122] determining phase information according to the first axis of symmetry;

[0123] When the microwave phase is fixed, the microwave amplitude is changed to determine a second 1-state probability variation diagram according to the changed microwave amplitude, wherein the second 1-state probability variation diagram has a second symmetry axis;

[0124] Amplitude information is determined based on the second axis of symmetry.

[0125] According to an embodiment of the present application, for a group of bit pairs, the microwave pulse time obtained by the above measurement is selected and frequency offset (or the microwave pulse time at any maximum point and Phase ), a microwave sequence (i.e., compensation microwave) of the same frequency (i.e., microwave source frequency) is simultaneously injected into the control line of the to-be-corrected bit (i.e., the quantum bit to be corrected) and the target control line of the target quantum bit, and the amplitude and phase of the compensation microwave are adjusted. When the amplitude and phase of the compensation microwave are completely offset by the crosstalk signal, the probability of the quantum bit to be corrected being in the 1 state will drop to 0. Therefore, on the compensation microwave IQ plane, the probability of the bit being in the 1 state will present a series of concentric circles centered on the IQ point of the crosstalk signal, and the radius of each circle increases with the number of pulses. increases and decreases. That is, as The larger the value, the more accurate the measurement of crosstalk signal will be. However, due to the influence of pulse sequence length and bit T1, T2, etc., when When it exceeds a certain level, the measurement accuracy will have a certain upper limit due to bit decoherence.

[0126] According to the embodiment of the present application, in order to save time in actual use, the intensity and phase of the microwave signal can be compensated by iterative scanning based on the estimated crosstalk size as the initial value. The specific process is as follows:

[0127] (1) Fix the amplitude of the compensation microwave, change the phase of the compensation microwave, and measure the probability of the 1 state. Since the intensity of the compensation microwave and the crosstalk signal will fluctuate between a minimum value close to 0 and a maximum value twice the intensity of the crosstalk signal after the compensation microwave and the crosstalk signal are combined, its image (i.e., the first 1 state probability change graph) will be at two phases different. There are two symmetry axes at the position, and the position of the symmetry axis is related to the number of pulses. Regardless of this, this axis (i.e., the first symmetry axis) corresponds to the phase information of the compensation microwave.

[0128] (2) Fix the phase of the compensation microwave, change the amplitude of the compensation microwave, and measure the probability of the 1 state. When the intensities of the compensation microwave and the crosstalk signal are almost the same, the intensity of the synthesized microwave will reach an extreme value near 0; when the intensity of the compensation microwave is slightly changed, the probability of the 1 state will change due to the increase in the intensity of the synthesized microwave, and then its image (i.e., the second 1 state probability change graph) will have a value that is consistent with the number of pulses. The second symmetry axis is irrelevant, and if the phase of the compensation microwave is also accurate, the probability of state 1 should be close to 0. This axis corresponds to the amplitude information of the compensation microwave.

[0129] Figure 4 A 1-state probability change diagram according to an embodiment of the present application is shown. Figure 5 A 1-state probability change diagram according to another embodiment of the present application is shown.

[0130] In a specific embodiment, it is assumed in the simulation that the X / 2 gate is added to the system through an ideal square wave. Then, in the rotating reference frame of the microwave frequency, the system Hamiltonian Approximately

[0131]

[0132]

[0133]

[0134]

[0135] in, is the reduced Hamiltonian constant, is the Pauli Z operator, is the Pauli X operator, is the frequency of the qubit to be corrected, is the microwave source frequency, is the microwave frequency difference, is the detuned Rabi frequency of the quantum bit to be corrected, is the rotation axis vector of the detuned Rabi oscillation of the quantum bit to be corrected on the Block sphere, is the phase of the microwave pulse.

[0136] This Hamiltonian states that the quantum state moves along the axis At angular velocity The gate duration of the pulse used just makes the quantum state rotate 180°. The frequency difference between the microwave source frequency and the quantum bit to be corrected is selected as 106.38MHz, the crosstalk intensity is 1.793MHz, and the pulse sequence uses 60×2 microwave pulses. The relationship between the probability of state 1 and the microwave pulse frequency and duration of the two simulation schemes is shown in the figure. Figure 4 shown. Figure 4 The ellipse in the figure is the position of the target peak.

[0137] Using formula (1) and Figure 4 The target peak position in (107.12MHz, 14ns, k=1) is calculated to be about 2.213MHz. Using formula (2) and Figure 5 The target peak position in (107.14MHz, 14ns, k=1) is calculated to be about 0.782MHz. Figure 4 and Figure 5 The horizontal axis in is , the vertical axis is the scan variable t.

[0138] Figure 6 A linear fitting schematic diagram according to an embodiment of the present application is shown.

[0139] In another embodiment, referring to Figure 6, there will be a target peak on the microwave pulse phase axis, and its corresponding microwave pulse time will be recorded and phase information , and then perform linear fitting on the above maximum points to deduce the target phase The corresponding target pulse time ,in, Figure 6 The middle ellipse is the target phase The target point at which the vertical coordinate is the target pulse time .

[0140] Using formula (2) and Figure 6 The position of the ellipse ( ), the crosstalk intensity can be calculated to be approximately 1.992MHz.

[0141] Figure 7 A linear fitting schematic diagram according to another embodiment of the present application is shown.

[0142] In another embodiment, referring to Figure 7 , there will be a target peak on the microwave pulse phase axis, and its corresponding microwave pulse time will be recorded and phase information , and then perform linear fitting on the above maximum points to deduce the target phase The corresponding target pulse time ,in, Figure 6 The middle ellipse is the target phase The target point at which the vertical coordinate is the target pulse time .

[0143] Using formula (2) and Figure 7 The position of the ellipse ( , k=1), the calculated crosstalk intensity is about 0.199MHz. (The figure samples 1001 points in the phase direction, and the peak width is about ). The estimated crosstalk intensity levels of both are close to the set crosstalk intensity levels.

[0144] Figure 8 A schematic diagram showing the measured relationship between frequency and duration changes according to an embodiment of the present application is shown.

[0145] To facilitate testing, a group of bit pairs and microwave control lines without control line crosstalk were selected. When the target control line was set to input microwave, a small microwave was simultaneously input into the control line to be corrected to simulate the impact of microwave control line crosstalk and calibrate the crosstalk intensity.

[0146] Figure 8 The pulse sequence used The microwave pulse has a frequency difference of 106.38MHz between the microwave source frequency and the frequency of the quantum bit to be corrected. Figure 8 A peak with a half-width of about 0.5 MHz can be seen in the image, which is the target peak.

[0147] Using formula (1) and the position of the target peak (0.7 MHz, 14 ns, k = 1), the crosstalk intensity information can be calculated to be approximately 3.54 MHz, and the actual introduced crosstalk value is 10.08 MHz.

[0148] Fig. 9 A schematic diagram showing the measured relationship between frequency and duration changes according to another embodiment of the present application is shown.

[0149] Fig. 9 The pulse sequence used A microwave pulse, the frequency difference between the microwave source frequency and the frequency of the quantum bit to be corrected is 106.38 MHz. A peak with a half-width of about 0.1 MHz can be seen in the figure, which is the target peak.

[0150] Using formula (1) and the position of the peak above (0.75MHz, 14ns, k=1), we can calculate that the crosstalk intensity is about 1.35MHz, and the actual introduced crosstalk value is 1.7927MHz.

[0151] Figure 8 and Fig. 9 The crosstalk intensity levels estimated by both methods are close to the set crosstalk intensity levels.

[0152] Figures 10(a), 10(b) and 10(c) show the relationship between the target state probability and the compensation microwave amplitude and phase according to the embodiment of the present application. In the experiment, as the number of microwave pulses increases, the relationship between the 1 state probability and the compensation microwave amplitude and phase changes.

[0153] Figure 10(a), Figure 10(b) and Figure 10(c) are the microwave pulse numbers. , , When the microwave amplitude and phase are compensated, the probability of state 1 is also changed. As shown in Figure 10 (a), Figure 10 (b) and Figure 10 (c), the radius of the concentric rings of the image decreases as the number of microwave pulses increases.

[0154] Fig. 11 (a) shows an experimental diagram of iterative scanning of microwave amplitude and microwave phase according to an embodiment of the present application. The dotted line in Fig. 11 (a) represents the microwave phase symmetry axis, that is, the first symmetry axis.

[0155] Fig. 11(b) shows an experimental diagram of iterative scanning of microwave amplitude and microwave phase according to an embodiment of the present application. The dotted line in Fig. 11(b) represents the microwave amplitude symmetry axis, that is, the second symmetry axis.

[0156] Fig. 11 (c) shows an experimental diagram of iterative scanning of microwave amplitude and microwave phase according to an embodiment of the present application. The left dotted line in the figure is the first symmetry axis before adjusting the microwave amplitude, and the right dotted line is the first symmetry axis after adjusting the microwave amplitude.

[0157] Fig. 11 (d) shows an experimental diagram of iterative scanning of microwave amplitude and microwave phase according to an embodiment of the present application. The left dotted line in the figure is the second symmetry axis before adjusting the microwave phase, and the right dotted line is the second symmetry axis after adjusting the microwave phase.

[0158] Figures 11(a), 11(b), 11(c) and 11(d) are the result diagrams of the probability of state 1 under different pulse numbers N after two iterative scans of the amplitude and phase of the compensation microwave. After two iterative scans, the amplitude and phase information of the compensation microwave can be determined more accurately.

[0159] FIG12( a ) is a schematic diagram showing the difference between a single-bit gate XEB before and after correction according to an embodiment of the present application.

[0160] The experiment uses two bits with large microwave control line crosstalk as test bits, and their serial XEB (cross entropy benchmark test) error rates can reach below 0.1%.

[0161] FIG12( b ) is a schematic diagram showing the difference between the single-bit gate XEB before and after correction according to an embodiment of the present application.

[0162] When testing XEB in parallel, one of the bits had crosstalk on the control line, and the XEB error rate quickly increased to over 6%.

[0163] FIG12( c ) is a schematic diagram showing the difference between the single-bit gate XEB before and after correction according to an embodiment of the present application.

[0164] Among them, Figure 12 (a) is a serial test, which is used to illustrate that the error rates of the two bits themselves are very low. Figure 12 (b) is a parallel test. Through the control experiment with Figure 12 (a), it is proved that serial or parallel (that is, whether the control line (target control line) of another bit (the qubit to be calibrated) also inputs microwaves during the XEB of one bit (the qubit to be calibrated)) is the only variable between the experiments of Figure 12 (a) and Figure 12 (b), which is the reason for the rapid increase in the error rate of one bit in Figure 12 (b). This further shows that there is a crosstalk signal from one bit in the line to another bit (the qubit to be calibrated).

[0165] Figure 12 (c) is also a parallel test. Through the control experiment with Figure 12 (b), it is proved that whether the compensation microwave is input during the parallel period, as the only variable between the experiments of Figure 12 (b) and Figure 12 (c), is the reason for the rapid decrease of the bit error rate in Figure 12 (c). This further shows that the compensation microwave can offset the crosstalk signal.

[0166] After correction, its parallel XEB can return to a state almost identical to the serial result, indicating that the measured compensation microwave can effectively alleviate the error introduced by the crosstalk signal of the target control line, as shown in Figure 12 (c). The lower curve in Figure 12 (c) is the error rate without applying the compensation microwave, and the upper curve is the error rate after applying the compensation microwave. Among them, the vertical coordinates in Figures 12 (a), 12 (b), and 12 (c) are the fidelity of the single-bit gate.

[0167] It should be further explained that the microwave pulse sequence of X2P and X2M alternately used in the present application, as shown in Figures 12 (a), 12 (b), and 12 (c), helps to eliminate the waiting time between pulses, shorten the length of the overall pulse sequence, and thus shorten the measurement time. In addition, the present application adopts a scheme of scanning the duration of each microwave in the microwave pulse sequence, which can increase the amplification effect of each microwave on the detuned Rabi, thereby reducing the number of microwave pulses required to finally obtain a sufficient signal-to-noise ratio.

[0168] In addition, the present application adopts a method of slightly changing the microwave source frequency and scanning the microwave source frequency to obtain a measurement accuracy higher than the microwave source sampling rate. This solution is necessary for situations where N is large, and can effectively capture detuned Rabi amplified signals with a half-width at half maximum of less than 0.5MHz. The present application uses a method of finding a symmetry axis to replace the two-dimensional scanning method of the IQ plane, which reduces the sampling time and can improve the measurement accuracy within a certain range through repeated iterations.

[0169] According to an embodiment of the present application, a microwave crosstalk correction method for a quantum bit includes:

[0170] Selecting a first microwave control line and at least one second microwave control line respectively, wherein the first microwave control line serves as a microwave source for a first quantum bit, and one second microwave control line serves as a microwave source for a second quantum bit;

[0171] Applying a compensating microwave corresponding to the first qubit on the second microwave control line to correct the crosstalk caused by the first qubit to the second microwave control line; and / or

[0172] Exchange or change different microwave control lines into the first microwave control line and the second microwave control line, that is, the second microwave control line of a first quantum bit can be used as the second microwave control line of other first quantum bits, and the control line can also be used as the first control line, and use at least one control line of the quantum bit to be corrected as the second microwave control line.

[0173] According to an embodiment of the present application, when the first quantum bit is , the second qubit is In this case, the first quantum bit is controlled by the first microwave The second qubit on the second microwave control line Cause crosstalk, then the second microwave control line can be applied to the first quantum bit The corresponding crosstalk signal is offset by a compensating microwave to process the crosstalk. For the first qubit The crosstalk can be exerted on the first microwave control line with the second quantum bit The corresponding crosstalk signals are offset by compensation microwaves to process the crosstalk, but the above two crosstalk signals are generally different and need to be calibrated separately.

[0174] According to an embodiment of the present application, the quantum bit to be calibrated is obtained by calibrating the quantum bit to be calibrated, and a microwave pulse sequence is applied to the microwave control line of the initial quantum bit to determine at least one target peak from the 1-state probability change diagram obtained by sampling and measuring the probability of the target state in the quantum bit to be corrected according to the quantum bit to be calibrated, thereby calculating the crosstalk intensity information of the quantum bit to be corrected on the quantum bit to be calibrated according to the parameters of the target peak combined with the crosstalk calculation formula, thereby generating compensation microwaves according to the crosstalk intensity information. The compensation microwave generation method of the present application has low computational complexity and good signal-to-noise ratio, and can effectively eliminate the influence of crosstalk in the quantum bit on the gate fidelity. At the same time, since the above-mentioned quantum bits to be calibrated do not affect each other, the crosstalk intensity information and compensation microwaves of the same quantum bit to be calibrated on different quantum bits to be calibrated can be calibrated and calculated in parallel.

[0175] The embodiments of the present application are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present application. Although each embodiment is described above, this does not mean that the measures in each embodiment cannot be used in combination advantageously. The present application does not depart from the scope of the present application, and those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present application.

Claims

1. A method for generating compensating microwaves for quantum bit crosstalk correction, It is characterized in that include: Calibrate the quantum bit to be calibrated to obtain the quantum bit to be calibrated, wherein the quantum bit to be calibrated includes a target gate, different state marks and a bit frequency, and at least one quantum bit to be corrected causes crosstalk to the quantum bit to be calibrated. When a microwave pulse sequence is applied to any of the quantum bits to be corrected to form the quantum bits to be calibrated, the microwave control line is used as the target control line, and a microwave pulse sequence is applied to the target control line to sample and measure the probability of the target state in the quantum bits to be calibrated, wherein the phase difference between two adjacent pulses in the microwave pulse sequence is a preset value, and the microwave pulse sequence has a microwave source frequency; Determine at least one target peak based on a 1-state probability variation diagram, wherein the 1-state probability variation diagram is generated according to the probability obtained by sampling, and the target peak includes a microwave pulse time and a microwave parameter corresponding to the microwave pulse time; Generate crosstalk intensity information of crosstalk caused by the to-be-corrected quantum bit to the to-be-calibrated quantum bit according to the microwave pulse time, the microwave parameters and the crosstalk calculation formula, so as to generate the compensating microwave according to the crosstalk intensity information; Wherein, the microwave parameters include a frequency offset corresponding to the microwave pulse time, or phase information and a microwave frequency difference corresponding to the microwave pulse time; Among them, generating crosstalk intensity information of crosstalk caused by the quantum bit to be calibrated to the quantum bit to be corrected according to the microwave pulse time, the microwave parameters and the crosstalk calculation formula includes: Based on a first crosstalk calculation formula, generating the crosstalk intensity information according to the microwave pulse time and the frequency offset; or Based on a second crosstalk calculation formula, the crosstalk intensity information is generated according to the microwave pulse time, the phase information and the microwave frequency difference.

2. The method according to claim 1, It is characterized in that Based on the second crosstalk calculation formula, the crosstalk intensity information is generated according to the microwave pulse time, the phase information and the microwave frequency difference, including: Performing fitting processing on the microwave pulse time and the phase information corresponding to each target peak to obtain a linear fitting function; determining a target pulse time at a target phase according to the linear fitting function; Based on the second crosstalk calculation formula, the crosstalk intensity information is generated according to the target pulse time and the microwave frequency difference.

3. The method according to claim 2, It is characterized in that The first crosstalk calculation formula is shown in formula (1), and the second crosstalk calculation formula is shown in formula (2): （1） （2） in, is the microwave pulse time, is the microwave frequency difference, is the frequency offset, Indicates that the target peak is from the sampling time The first few peaks, for the i-th target peak, , is the crosstalk strength information, is the target pulse time.

4. The method according to claim 1, It is characterized in that Applying a microwave pulse sequence on the target control line to sample and measure the probability of a target state in the qubit to be calibrated and the qubit to be corrected, comprising: Acquire the microwave pulse sequence, wherein the microwave pulse sequence includes pulses, the duration of each pulse being a scan variable; Applying the microwave pulse sequence to the target control line to sample and measure the probability of the target state in the qubit to be calibrated and the qubit to be corrected; When the target peak cannot be determined on the 1-state probability variation diagram corresponding to the measured probability, the microwave pulse sequence or microwave parameters are adjusted to perform sampling measurement using the adjusted microwave pulse sequence or the adjusted microwave parameters.

5. The method according to claim 4, It is characterized in that The microwave pulse sequence or microwave parameters are adjusted to perform sampling measurement using the adjusted microwave pulse sequence or the adjusted microwave parameters, including: Adjusting the frequency of the pulses in the microwave pulse sequence to iteratively perform sampling measurement using the adjusted microwave pulse sequence; or The phases of the pulses in the microwave pulse sequence are adjusted to iteratively perform sampling measurement using the adjusted microwave pulse sequence.

6. The method according to claim 1, It is characterized in that Also includes: When the quantum bit to be corrected acts on the control line to be calibrated, the compensating microwave is loaded on the control line to be calibrated; Under the condition that the first parameter of the compensating microwave on the control line to be calibrated is fixed, the second parameter of the compensating microwave is changed to determine the phase information and the amplitude information of the compensating microwave according to the 1-state probability change diagram corresponding to the second parameter, so as to generate the final compensating microwave according to the crosstalk intensity information, the phase information and the amplitude information.

7. The method according to claim 6, It is characterized in that The first parameter and the second parameter both include microwave amplitude or microwave phase; Wherein, in the case of fixing the first parameter of the compensating microwave on the control line to be calibrated, changing the second parameter of the compensating microwave to determine the phase information and amplitude information of the compensating microwave according to the 1-state probability change diagram corresponding to the second parameter, comprises: Under the condition that the microwave amplitude is fixed, the microwave phase is changed to determine a first 1-state probability change diagram according to the changed microwave phase, wherein the first 1-state probability change diagram has a first symmetry axis; Determining the phase information according to the first symmetry axis; In the case of fixing the microwave phase, changing the microwave amplitude to determine a second 1-state probability change diagram according to the changed microwave amplitude, wherein the second 1-state probability change diagram has a second symmetry axis; The amplitude information is determined according to the second axis of symmetry.

8. A microwave crosstalk correction method for quantum bits, It is characterized in that include: Selecting a first microwave control line and at least one second microwave control line respectively, wherein the first microwave control line serves as a microwave source for a first quantum bit, and one of the second microwave control lines serves as a microwave source for a second quantum bit; Applying a compensating microwave corresponding to the first qubit on the second microwave control line to correct the crosstalk caused by the first qubit to the second microwave control line; and / or Exchanging or changing different microwave control lines into first microwave control lines and second microwave control lines, that is, the second microwave control line of a first quantum bit can be used as the second microwave control line of other first quantum bits, and the control line can also be used as the first control line, and the control line of at least one quantum bit to be corrected is used as the second microwave control line; Wherein, the compensating microwave is generated by the compensating microwave generating method described in any one of claims 1 to 7.

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