Method for calibrating single-bit gate fidelity under drive crosstalk

Abstract

The present invention provides a method for calibrating the fidelity of a single-bit gate under drive crosstalk, including: providing a quantum chip, on which a first qubit and a second qubit are arranged; applying a drive signal to the first qubit, applying an operation sequence to the second qubit and obtaining the fidelity of the operation sequence, wherein the operation sequence includes m single-bit Clifford gates, and the single-bit Clifford gate includes several single-bit gates; obtaining the fidelity of the second qubit when performing a single-bit gate under the drive crosstalk from the first qubit based on the relationship between the fidelity of the operation sequence and m. The technical solution of the present application can calibrate the fidelity of a single-bit gate when a qubit on a quantum chip is under the drive crosstalk from other qubits.

Description

Technical Field

[0001] The present invention belongs to the technical field of quantum computing, and particularly relates to a method and apparatus for calibrating the fidelity of a single-qubit gate under calibration-driven crosstalk, a quantum computer, and a readable storage medium. Background Art

[0002] Physical systems for realizing quantum computing include superconducting quantum computing, semiconductor quantum computing, ion trap quantum computing, etc. The core of superconducting quantum computing is a superconducting quantum chip, and a plurality of qubits are arranged on the superconducting quantum chip. When modulating a qubit in the superconducting quantum chip, it is necessary to use an XY signal transmission line (or microwave drive line) to transmit a microwave drive signal to the corresponding qubit to control the energy level transition of the qubit.

[0003] During the execution of a multi-qubit quantum circuit, a single qubit is prone to being affected by microwave pulses in the XY signal transmission line (or microwave drive line) that drives other qubits, and thus an unwanted quantum state excitation occurs. This phenomenon is called drive crosstalk. When executing a single-qubit gate, due to the unwanted quantum state excitation caused by drive crosstalk, the fidelity of the gate will be reduced.

[0004] In order to calibrate the fidelity of a single-qubit gate under drive crosstalk, we need to propose a method for calibrating the fidelity of a single-qubit gate under drive crosstalk.

[0005] It should be noted that the information disclosed in the background art part of the present application is only intended to deepen the understanding of the general background technology of the present application, and should not be regarded as an admission or any form of suggestion that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0006] The object of the present invention is to provide a method and apparatus for calibrating the fidelity of a single-qubit gate under drive crosstalk, a method for calibrating the influence degree of drive crosstalk on the fidelity of a single-qubit gate, a quantum computer, and a readable storage medium. The method for calibrating the fidelity of a single-qubit gate under drive crosstalk can obtain the fidelity of a single qubit on a quantum chip when executing a single-qubit gate under the drive crosstalk of another qubit.

[0007] To achieve the above object, in a first aspect, the present invention provides a method for calibrating the fidelity of a single-qubit gate under drive crosstalk, which is characterized by comprising:

[0008] Providing a quantum chip, on which a first qubit and a second qubit are arranged;

[0009] Apply a driving signal to the first qubit, apply an operation sequence to the second qubit and obtain the fidelity of the operation sequence, where the operation sequence includes m single-qubit Clifford gates, and the single-qubit Clifford gate includes several single-qubit gates;

[0010] Obtain the fidelity of the single-qubit gate when the second qubit executes under the driving crosstalk from the first qubit based on the relationship between the fidelity of the operation sequence and m.

[0011] Preferably, the step of applying a driving signal to the first qubit, applying an operation sequence to the second qubit and obtaining the fidelity of the operation sequence includes:

[0012] Set different values of m, apply a driving signal to the first qubit under different values of m, and during the existence time of the driving signal, apply an operation sequence with m single-qubit Clifford gates to the second qubit, and obtain the fidelity of each operation sequence to obtain the fidelities of multiple operation sequences under different m values.

[0013] Preferably, the method for obtaining the fidelity of each operation sequence specifically includes:

[0014] Stop applying the driving signal to the first qubit, apply an inverse operation to the second qubit, and the inverse operation is the inverse of the m single-qubit Clifford gates;

[0015] Obtain the probability that the second qubit is in the initial state;

[0016] Take the probability that the second qubit is in the initial state as the fidelity of the operation sequence.

[0017] Preferably, the step of obtaining the fidelity of the single-qubit gate when the second qubit executes under the driving crosstalk from the first qubit based on the relationship between the fidelity of the operation sequence and m includes:

[0018] Fit the relationship between the fidelities of the obtained multiple operation sequences and the corresponding m to satisfy the first formula:

[0019] y = A×p m +B

[0020] where y is the fidelity of the operation sequence, A is a parameter related to the state preparation fidelity, B is a parameter related to the measurement fidelity, and p is a parameter related to the fidelity of the single-qubit gate;

[0021] Obtain the parameter p related to the fidelity of the single-qubit gate based on the first formula;

[0022] According to the formula calculate the fidelity of the single-qubit gate, where F is the fidelity of the single-qubit gate.

[0023] Preferably, applying a driving signal to the first qubit, applying an operation sequence to the second qubit and obtaining the fidelity of the operation sequence includes:

[0024] Repeatedly execute applying an operation sequence to the second qubit when the first qubit receives a driving signal, and obtain the sub-fidelity of the operation sequence. Take the average value of the sub-fidelities of the operation sequences obtained by multiple executions as the fidelity of the operation sequence.

[0025] Preferably, the frequency of the driving signal is kept consistent with the frequency of the second qubit within the error range.

[0026] Preferably, the error range is 0 to 2Mhz.

[0027] In a second aspect, the present application provides a method for calibrating the fidelity of a single-qubit gate under drive crosstalk, including:

[0028] Provide a quantum chip, on which a first qubit and a second qubit are arranged;

[0029] Apply a driving signal to the first qubit, and apply an operation sequence to the second qubit during the existence time of the driving signal, where the operation sequence includes m single-qubit Clifford gates, and the single-qubit Clifford gate includes several single-qubit gates;

[0030] Stop applying the driving signal to the first qubit, apply an inverse operation to the second qubit, and obtain the probability that the second qubit is in the initial state. The inverse operation is the inverse of the m single-qubit Clifford gates;

[0031] Obtain the fidelity of the operation sequence according to the probability that the second qubit is in the initial state;

[0032] Based on the relationship between the fidelity of the operation sequence and m, obtain the fidelity of the single-qubit gate when the second qubit is subjected to drive crosstalk from the first qubit.

[0033] Preferably, obtaining the fidelity of the operation sequence according to the probability that the second qubit is in the initial state includes:

[0034] Taking the probability that the second qubit is in the initial state as the fidelity of the operation sequence.

[0035] Preferably, obtaining the fidelity of the operation sequence according to the probability that the second qubit is in the initial state includes:

[0036] Repeatedly applying a driving signal to the first qubit, and applying an operation sequence to the second qubit during the existence time of the driving signal; stopping applying the driving signal to the first qubit, applying an inverse operation to the second qubit, and obtaining the probability that the second qubit is in the initial state;

[0037] Taking the average value of the probabilities of the second qubit obtained multiple times as the fidelity of the operation sequence.

[0038] In a third aspect, the present application provides a method for calibrating the influence degree of drive crosstalk on the fidelity of a single-qubit gate, including:

[0039] Providing a quantum chip, on which a first qubit and a second qubit are arranged;

[0040] Obtaining the first fidelity, which is the fidelity of performing a single-qubit gate when the second qubit is not affected by the drive crosstalk from the first qubit;

[0041] Using the method for calibrating the fidelity of a single-qubit gate under drive crosstalk provided by the present application to obtain the second fidelity, which is the fidelity of performing a single-qubit gate when the second qubit is affected by the drive crosstalk from the first qubit;

[0042] Calibrating the influence degree of drive crosstalk on the fidelity based on the first fidelity and the second fidelity.

[0043] In a fourth aspect, the present application provides a device for calibrating the fidelity of a single-qubit gate under drive crosstalk, including:

[0044] A quantum chip, on which a first qubit and a second qubit are arranged;

[0045] An operation sequence fidelity acquisition module, configured to apply an operation sequence to the second qubit and obtain the fidelity of the operation sequence when the first qubit receives a driving signal; wherein, the operation sequence includes m single-qubit Clifford gates;

[0046] A single-qubit gate fidelity acquisition module, configured to obtain the fidelity of the second qubit performing a single-qubit gate when being affected by the drive crosstalk from the first qubit based on the relationship between the fidelity of the operation sequence and m.

[0047] Fifth aspect, the present application provides a readable storage medium, on which a computer program is stored, and when the computer program is executed, it can implement the method for calibrating the single-bit gate fidelity under drive crosstalk provided by the present application.

[0048] Sixth aspect, the present application provides a quantum computer, including the device for calibrating the single-bit gate fidelity under drive crosstalk provided by the present application.

[0049] Compared with the prior art, it has the following beneficial effects:

[0050] The method for calibrating the single-bit gate fidelity under drive crosstalk provided by the present invention includes: in the first step, providing a quantum chip on which a first qubit and a second qubit are arranged; in the second step, applying a drive signal to the first qubit, applying an operation sequence to the second qubit and obtaining the fidelity of the operation sequence, where the operation sequence includes m single-bit Clifford gates, and the single-bit Clifford gate includes several single-bit gates; in the third step, obtaining the fidelity of the second qubit when performing a single-bit gate under the drive crosstalk from the first qubit based on the relationship between the fidelity of the operation sequence and m. The method for calibrating the single-bit gate fidelity under drive crosstalk provided by the present application can calibrate the fidelity of a qubit on a quantum chip when performing a single-bit gate under the drive crosstalk from other qubits, and further can calibrate the influence degree of drive crosstalk on the single-bit gate fidelity, which is beneficial for researchers to optimize the quantum chip according to the influence degree.

[0051] The device for calibrating the single-bit gate fidelity under drive crosstalk, the method for calibrating the influence degree of drive crosstalk on the single-bit gate fidelity, the readable storage medium and the quantum computer proposed by the present invention belong to the same inventive concept as the method for calibrating the single-bit gate fidelity under drive crosstalk, and thus have the same beneficial effects, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings without creative efforts based on these drawings.

[0053] Figure 1 It is a schematic flowchart of the method for calibrating the single-bit gate fidelity under drive crosstalk in an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] The specific embodiments of the present invention will be described in more detail below in conjunction with the schematic diagrams. The advantages and features of the present invention will be clearer according to the following description and the claims. It should be noted that the drawings are all in a very simplified form and use non-precise scales, only for the purpose of facilitating and clearly assisting in explaining the purpose of the embodiments of the present invention.

[0055] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0056] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0057] <Example 1>

[0058] This embodiment provides a method for calibrating the fidelity of a single-bit gate under drive crosstalk. Please refer to Figure 1 , Figure 1 which is a schematic flowchart of the method for calibrating the fidelity of a single-bit gate under drive crosstalk provided in this embodiment. It can be seen from Figure 1 that the method includes:

[0059] S1: Provide a quantum chip, on which a first qubit and a second qubit are provided;

[0060] S2: Apply a drive signal to the first qubit, apply an operation sequence to the second qubit and obtain the fidelity of the operation sequence, where the operation sequence includes m single-bit Clifford gates, and the single-bit Clifford gate includes several single-bit gates;

[0061] S3: Obtain the fidelity of the second qubit when performing a single-bit gate under the drive crosstalk from the first qubit based on the relationship between the fidelity of the operation sequence and m.

[0062] In the step S1, in addition to the first qubit and the second qubit, the quantum chip may further include other qubits. Each qubit is coupled to each other, and each qubit is coupled to an XY signal transmission line and a Z signal transmission line.

[0063] The XY signal transmission line is used to transmit quantum state control signals, and the Z signal transmission line is used to transmit magnetic flux control signals; each qubit is further coupled to a resonator. One end of the resonator far from the corresponding qubit is connected to a data transmission bus integrally arranged on the quantum chip. The data transmission bus is used to receive qubit read signals and transmit qubit read feedback signals. By applying the qubit read signal to the resonator, and then reading the qubit read feedback signal transmitted or reflected from the resonator, the state of the qubit is determined by measuring the response of the resonator to microwaves.

[0064] As described in the background art, a single qubit is susceptible to the influence of microwave pulses in the XY signal transmission line (or microwave drive line) that drives other qubits, and thus unwanted quantum state excitations may occur. In this embodiment, taking the first qubit and the second qubit as examples, when the quantum state control signal is applied to the XY signal transmission line of the first qubit, the second qubit will also be affected by the quantum state control signal on the XY signal transmission line of the first qubit, and thus unwanted quantum state excitations will occur on the second qubit. At this time, if a single-qubit gate operation is performed on the second qubit, the fidelity of the gate operation will decrease.

[0065] In order to calibrate the fidelity of the single-qubit gate performed by the second qubit under the driving crosstalk from the first qubit, step S2 is adopted. A driving signal is applied to the first qubit. While the driving signal is applied to the first qubit, an operation sequence including m single-qubit Clifford gates is applied to the second qubit.

[0066] The purpose of applying m of the single-qubit Clifford gates is to continuously accumulate the error rate of the single-qubit gates for amplification to a level that is convenient for us to observe. Assume that the initial state of the second qubit (the quantum state before receiving the operation sequence) is the first quantum state. Also assume that the operation of each single-qubit Clifford gate is perfect. Then, after the second qubit undergoes the operations of the operation sequence, it should be in the second quantum state. We can characterize the fidelity of the operation sequence by measuring the error between the quantum state of the second qubit after undergoing the operation sequence and the second quantum state. Since the operation sequence includes m single-qubit Clifford gates, step S3 can be taken to obtain the fidelity of the single-qubit gate based on the fidelity of the operation sequence and the value m. Additionally, it should be noted that the single-qubit Clifford gate includes several single-qubit gates, but generally, we use the fidelity of the single-qubit Clifford gate to represent the fidelity of the single-qubit gate.

[0067] The single-qubit Clifford gate refers to an element in the single-qubit Clifford group, and the single-qubit Clifford group is shown in Table 1:

[0068]

[0069]

[0070] The method for calibrating the fidelity of a single-qubit gate under drive crosstalk provided in this application can calibrate the fidelity of the second qubit when performing a single-qubit gate under the drive crosstalk from the first qubit, and further can calibrate the influence degree of the drive crosstalk on the fidelity of the single-qubit gate, which is beneficial for researchers to optimize the quantum chip according to the influence degree.

[0071] Specifically, in step S2, the operation of applying a drive signal to the first qubit, applying an operation sequence to the second qubit, and obtaining the fidelity of the operation sequence includes:

[0072] Set different values of m, and apply a drive signal to the first qubit under different values of m. During the existence time of the drive signal, apply an operation sequence with m single-qubit Clifford gates to the second qubit, and obtain the fidelity of each operation sequence to get the fidelities of multiple operation sequences under different m values.

[0073] During the execution of quantum state preparation and quantum state reading, errors also exist. The quantum state preparation operation is the operation of preparing the second qubit into the first quantum state, and the quantum state reading operation is the operation of reading the quantum state of the second qubit after being operated by the operation sequence. In order to more accurately calibrate the fidelity of the second qubit performing single-bit gates under the drive crosstalk of the first qubit, it is necessary to consider the errors of the quantum state preparation operation and the quantum state reading operation.

[0074] When performing the above operations with different values of m, operation sequences with different numbers of single-bit Clifford gates have different operation sequence fidelities. Based on the relationship between the fidelities of the obtained multiple operation sequences and m, relationship fitting can obtain a formula including the error of the quantum state preparation operation and the error of the quantum state reading.

[0075] Specifically, obtaining the fidelity of the second qubit performing single-bit gates when being driven by crosstalk from the first qubit based on the relationship between the fidelity of the operation sequence and m includes:

[0076] Fitting the relationship between the fidelity of the obtained multiple operation sequences and the corresponding m to the relationship between the fidelity of the operation sequence and m, which satisfies the first formula:

[0077] y = A × p m + B

[0078] where y is the fidelity of the operation sequence, A is a parameter related to the state preparation fidelity, B is a parameter related to the measurement fidelity, and p is a parameter related to the fidelity of the single-bit gate;

[0079] Obtaining the parameter p related to the fidelity of the single-bit gate based on the first formula;

[0080] According to the formula Calculate the fidelity of the single-bit gate, where F is the fidelity of the single-bit gate.

[0081] Based on the fidelities of the obtained multiple operation sequences and the corresponding m, fitting the relationship between the fidelity of the operation sequence and m can obtain the parameter A related to the fidelity of the quantum state preparation operation and the parameter B related to the fidelity of the quantum state reading operation, and can more accurately calibrate the fidelity of the second qubit performing single-bit gates under the drive crosstalk of the first qubit.

[0082] In addition, the method for obtaining the fidelity of each operation sequence specifically includes:

[0083] Stop applying the drive signal to the first qubit, and apply an inverse operation to the second qubit, where the inverse operation is the inverse of the m single-qubit Clifford gates;

[0084] Obtain the probability that the second qubit is in the initial state;

[0085] Use the probability that the second qubit is in the initial state as the fidelity of the operation sequence.

[0086] When the drive signal is not applied to the first qubit, an inverse operation can be applied to the second qubit. The inverse operation is the inverse of the m single-qubit Clifford gates in the operation sequence. Assuming that all the single-qubit Clifford gate operations are perfect, after the inverse operation, the second qubit should be in the initial state (i.e., the first quantum state), that is, at this time the second quantum state is the first quantum state. By measuring the error between the quantum state of the second qubit and the first quantum state, the fidelity of the operation sequence can be characterized. Generally, we set the first quantum state (or the initial state) to the |0> state for easy operation.

[0087] Furthermore, to more accurately characterize the fidelity of the operation sequence, applying a drive signal to the first qubit, applying an operation sequence to the second qubit, and obtaining the fidelity of the operation sequence include:

[0088] Repeat the execution of applying an operation sequence to the second qubit when a drive signal is received by the first qubit multiple times, and obtain the sub-fidelity of the operation sequence. Use the average value of the sub-fidelities of the operation sequence obtained by multiple executions as the fidelity of the operation sequence.

[0089] By repeatedly applying the operation sequence with a certain m value to the second qubit multiple times and obtaining the sub-fidelity of the operation sequence, and using the average value of multiple sub-fidelities as the fidelity of the operation sequence with this value of m, the measurement accuracy can be improved and the error caused by a single experiment can be avoided.

[0090] Additionally, the frequency of the drive signal applied to the first qubit is kept consistent with the frequency of the second qubit within the error range. Generally, the error range is 0 to 2Mhz. Generally, the drive signal is generally a π pulse.

[0091] In summary, the method for calibrating the single-bit gate fidelity under drive crosstalk provided by this application includes: providing a quantum chip on which a first qubit and a second qubit are arranged; applying a drive signal to the first qubit, applying an operation sequence to the second qubit and obtaining the fidelity of the operation sequence, where the operation sequence includes m single-bit Clifford gates, and the single-bit Clifford gate includes several single-bit gates; obtaining the fidelity of the second qubit when performing a single-bit gate under the drive crosstalk from the first qubit based on the relationship between the fidelity of the operation sequence and m. The technical solution of this application can calibrate the fidelity of a single-bit gate when a qubit on a quantum chip is under the drive crosstalk from other qubits, and further can calibrate the influence degree of the drive crosstalk on the single-bit gate fidelity, which is beneficial for researchers to optimize the quantum chip according to the influence degree.

[0092] <Example 2>

[0093] This embodiment provides a calibration method for calibrating the influence degree of drive crosstalk on the single-bit gate fidelity. The calibration method includes: providing a quantum chip on which a first qubit and a second qubit are arranged; obtaining the fidelity of the second qubit when performing a single-bit gate without being under the drive crosstalk from the first qubit as the first fidelity; using the method for calibrating the single-bit gate fidelity under drive crosstalk provided by this application to obtain the fidelity of the second qubit when performing a single-bit gate under the drive crosstalk from the first qubit as the second fidelity; calibrating the influence degree of the drive crosstalk on the fidelity based on the first fidelity and the second fidelity.

[0094] The technical solution of this embodiment can obtain the influence degree of the drive crosstalk on the fidelity of the second qubit when performing a single-bit gate by respectively measuring the fidelity of the second qubit when performing a single-bit gate with and without being under the drive crosstalk from the first qubit, obtaining the first fidelity and the second fidelity respectively, and making a comparison.

[0095] <Example 3>

[0096] This embodiment provides a device for calibrating the single-bit gate fidelity under drive crosstalk. The device includes:

[0097] a quantum chip on which a first qubit and a second qubit are arranged;

[0098] An operation sequence fidelity acquisition module is configured to apply an operation sequence to the second qubit and acquire the fidelity of the operation sequence when the first qubit receives a driving signal; wherein, the operation sequence includes m single-qubit Clifford gates;

[0099] A single-qubit gate fidelity acquisition module is configured to acquire the fidelity of the second qubit when performing a single-qubit gate under the driving crosstalk from the first qubit based on the relationship between the fidelity of the operation sequence and m.

[0100] The apparatus for calibrating the fidelity of a single-qubit gate under driving crosstalk in this embodiment and the method for calibrating the fidelity of a single-qubit gate under driving crosstalk provided in this application belong to the same inventive concept, and thus have the same beneficial effects, which will not be elaborated here.

[0101] <Embodiment Four>

[0102] Based on the same inventive concept, this embodiment provides a readable storage medium, on which a computer program is stored, and when the computer program is executed, it can implement the method for calibrating the fidelity of a single-qubit gate under driving crosstalk provided in this application.

[0103] <Embodiment Five>

[0104] Based on the same inventive concept, this embodiment provides a quantum computer, including the apparatus for calibrating the fidelity of a single-qubit gate under driving crosstalk provided in this application.

[0105] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention in any way. Any changes and modifications made by those of ordinary skill in the field of the present invention based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A method for calibrating the fidelity of a single-bit gate under drive crosstalk, characterized in that, Including: Providing a quantum chip, on which a first qubit and a second qubit are arranged; Applying a driving signal to the first qubit, applying an operation sequence to the second qubit and obtaining the fidelity of the operation sequence, wherein the operation sequence includes m single-qubit Clifford gates, and the single-qubit Clifford gate includes several single-qubit gates; Performing fitting based on the relationship between the fidelities of multiple obtained operation sequences and the corresponding m to obtain a first formula including quantum state preparation error and quantum state reading error; Obtaining a parameter p related to the fidelity of the single-qubit gate based on the first formula; Calculating the fidelity of the single-qubit gate according to the formula F = 1 - 1 / 2(1 - p), where F is the fidelity of the single-qubit gate.

2. The method for calibrating the single-bit gate fidelity under crosstalk of a driving string according to claim 1, wherein The step of applying a driving signal to the first qubit, applying an operation sequence to the second qubit and obtaining the fidelity of the operation sequence includes: Setting different values of m, applying a driving signal to the first qubit under different values of m, applying an operation sequence with m single-qubit Clifford gates to the second qubit during the existence time of the driving signal, and obtaining the fidelities of each operation sequence to obtain the fidelities of multiple operation sequences under different m values.

3. The method for calibrating the single-bit gate fidelity under drive crosstalk according to claim 2, wherein The method for obtaining the fidelity of each operation sequence specifically includes: Stopping applying the driving signal to the first qubit, applying an inverse operation to the second qubit, and the inverse operation is the inverse of the m single-qubit Clifford gates; Obtaining the probability that the second qubit is in the initial state; Taking the probability that the second qubit is in the initial state as the fidelity of the operation sequence.

4. The method for calibrating the fidelity of a single-qubit gate under driving crosstalk according to claim 2, wherein: The first formula is determined as: y = A × p m + B where y is the fidelity of the operation sequence, A is a parameter related to the state preparation fidelity, B is a parameter related to the measurement fidelity, and p is a parameter related to the fidelity of the single-qubit gate.

5. The method for calibrating the single-bit gate fidelity under drive crosstalk according to any one of claims 1 to 4, characterized in that The step of applying a driving signal to the first qubit, applying an operation sequence to the second qubit and obtaining the fidelity of the operation sequence includes: Repeatedly executing applying an operation sequence to the second qubit when the first qubit receives a driving signal, and obtaining the sub-fidelity of the operation sequence, and taking the average value of the sub-fidelities of the operation sequences obtained by repeatedly executing as the fidelity of the operation sequence.

6. The method for calibrating the single-bit gate fidelity under drive crosstalk according to claim 1, wherein The frequency of the driving signal is kept consistent with the frequency of the second qubit within the error range.

7. The method for calibrating the single-bit gate fidelity under drive crosstalk according to claim 6, characterized in that, The error range is 0 to 2Mhz.

8. A method for calibrating the fidelity of a single-bit gate under drive crosstalk, characterized in that, Including: Providing a quantum chip, on which a first qubit and a second qubit are arranged; Applying a driving signal to the first qubit, and applying an operation sequence to the second qubit during the existence time of the driving signal, wherein the operation sequence includes m single-qubit Clifford gates, and the single-qubit Clifford gate includes several single-qubit gates; Stop applying the driving signal to the first qubit, apply an inverse operation to the second qubit, and obtain the probability that the second qubit is in the initial state. The inverse operation is the inverse of the m single-qubit Clifford gates; Obtain the fidelity of the operation sequence according to the probability that the second qubit is in the initial state; Based on the relationship between the fidelities of the obtained multiple operation sequences and the corresponding m, perform fitting to obtain a first formula including the quantum state preparation error and the quantum state reading error; Based on the first formula, obtain the parameter p related to the fidelity of the single-qubit gate; Calculate the fidelity of the single-qubit gate according to the formula F = 1 - 1 / 2(1 - p), where F is the fidelity of the single-qubit gate.

9. The method for calibrating the single-bit gate fidelity under crosstalk of a driving string according to claim 8, characterized in that, The obtaining the fidelity of the operation sequence according to the probability that the second qubit is in the initial state includes: Taking the probability that the second qubit is in the initial state as the fidelity of the operation sequence.

10. The method for calibrating the single-bit gate fidelity under drive crosstalk according to claim 8, wherein, The obtaining the fidelity of the operation sequence according to the probability that the second qubit is in the initial state includes: Repeatedly execute applying a driving signal to the first qubit, applying an operation sequence to the second qubit during the existence time of the driving signal; stop applying the driving signal to the first qubit, apply an inverse operation to the second qubit, and obtain the probability that the second qubit is in the initial state; Taking the average value of the probabilities of the second qubit obtained multiple times as the fidelity of the operation sequence.

11. A calibration method for the influence degree of drive crosstalk on the fidelity of single-bit gates, characterized in that, Includes: Provide a quantum chip, on which a first qubit and a second qubit are provided; Obtain that the fidelity of performing a single-qubit gate when the second qubit is not affected by the driving crosstalk from the first qubit is the first fidelity; Adopt the method for calibrating the fidelity of a single-qubit gate under driving crosstalk according to any one of claims 1 to 10 to obtain that the fidelity of performing a single-qubit gate when the second qubit is affected by the driving crosstalk from the first qubit is the second fidelity; Based on the first fidelity and the second fidelity, calibrate the influence degree of the driving crosstalk on the fidelity.

12. An apparatus for calibrating the fidelity of a single-bit gate under drive crosstalk, characterized in that, Includes: A quantum chip, on which a first qubit and a second qubit are provided; An operation sequence fidelity acquisition module, configured to apply an operation sequence to the second qubit and obtain the fidelity of the operation sequence when the first qubit receives a driving signal; wherein, the operation sequence includes m single-qubit Clifford gates; A single-qubit gate fidelity acquisition module, configured to perform fitting based on the relationship between the fidelities of the obtained multiple operation sequences and the corresponding m to obtain a first formula including the quantum state preparation error and the quantum state reading error, obtain the parameter p related to the fidelity of the single-qubit gate based on the first formula, and calculate the fidelity of the single-qubit gate according to the formula F = 1 - 1 / 2(1 - p), where F is the fidelity of the single-qubit gate.

13. A readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed, it can implement the method for calibrating the fidelity of a single-qubit gate under driving crosstalk according to any one of claims 1 to 10.

14. A quantum computer, characterized in that, Comprising the apparatus for calibrating the single-bit gate fidelity under drive crosstalk as described in claim 12.

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