Method for obtaining a pulse implementing state exchange between two qubits

Abstract

The application provides an acquisition method of a pulse for realizing state exchange between two quantum bits, the pulse comprising a first waveform with a positive amplitude and a second waveform with a negative amplitude, the pulse being used for state exchange between a first quantum bit and a second quantum bit, and the acquisition method comprising: setting an operating point of the first quantum bit to a degenerate point, acquiring a first change relation of a bit frequency of the first quantum bit with a voltage value of a forward fast modulation signal applied and a second change relation with a voltage value of a reverse fast modulation signal applied; acquiring an amplitude of the first waveform, and acquiring a first frequency value of the first quantum bit based on the amplitude of the first waveform and the first change relation; and acquiring a first voltage value as the amplitude of the second waveform based on the first frequency value and the second change relation.

Description

Technical Field

[0001] This invention belongs to the field of quantum computing, and particularly relates to a method, apparatus, and quantum computer for obtaining pulses that realize state exchange between two qubits. Background Technology

[0002] Quantum computing and quantum information is an interdisciplinary field that uses the principles of quantum mechanics to perform computational and information processing tasks. It is closely related to quantum physics, computer science, and informatics. Quantum logic gates are the basic units for quantum computing. During the execution of a quantum circuit, different quantum logic gates need to be executed at different times, and different operating conditions need to be met, especially the frequency of the qubit. In superconducting systems, the frequency of the qubit is usually modulated by changing the voltage value on the AC line (i.e., the fast modulation signal line). The response of the AC voltage over time is the zamp pulse. Compared with other zamp pulses, SNZ (sudden variant of the net zeroscheme) pulses have the following advantages: less influence from low-frequency noise; interference cancellation suppresses leakage; less influence from long-range distortion; higher gate repeatability; and simpler pulse modulation. The SNZ pulses include zamp pulses of equal magnitude but opposite signs.

[0003] In non-ideal situations, when performing a two-bit gate operation using an SNZ pulse, an executable state exchange pulse is required. When a zamp pulse of equal magnitude but opposite sign is directly applied to the qubit, the latter half of the pulse may not be exchanged during the executable state exchange, thus making it impossible to efficiently execute the two-bit quantum logic gate.

[0004] Therefore, it is necessary to propose a method for obtaining the pulse that realizes the state exchange between two qubits, so that it can be used to perform two-qubit quantum logic gate operations.

[0005] It should be noted that the information disclosed in the background section of this application is intended only to enhance the understanding of the general background of this application, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a pulse that can realize state exchange between two qubits for use in two-qubit logic gate operations.

[0007] To achieve the above objectives, in a first aspect, this application provides a method for obtaining a pulse for state exchange between two qubits, the pulse comprising a first waveform with positive amplitude and a second waveform with negative amplitude, the pulse being used for state exchange between a first qubit and a second qubit, the method comprising:

[0008] Set the operating point of the first qubit to the degeneracy point, and obtain a first relationship between the bit frequency of the first qubit and the voltage value of the applied positive fast modulation signal, and a second relationship between the bit frequency and the voltage value of the applied reverse fast modulation signal.

[0009] The amplitude of the first waveform is obtained, and the first frequency value of the first quantum bit is obtained based on the amplitude of the first waveform and the first change relationship.

[0010] The first voltage value is obtained as the amplitude of the second waveform based on the first frequency value and the second change relationship.

[0011] Preferably, obtaining the first relationship between the bit frequency of the first qubit and the voltage value of the applied positive fast modulation signal, and the second relationship between the bit frequency and the voltage value of the applied negative fast modulation signal, includes:

[0012] The voltage value of the forward fast modulation signal or the voltage value of the reverse fast modulation signal applied to the first qubit are continuously changed, and a Ramsey experiment is performed on the first qubit at each voltage value to obtain the corresponding frequency value.

[0013] Based on the correspondence between the frequency value of the first quantum bit and the voltage value of the fast modulation signal, the first change relationship or the second change relationship is plotted.

[0014] Preferably, obtaining the first relationship between the bit frequency of the first qubit and the voltage value of the applied positive fast modulation signal, and the second relationship between the bit frequency and the voltage value of the applied negative fast modulation signal, includes:

[0015] The voltage value of the reverse fast modulation signal applied to the first quantum bit is continuously changed, and an energy spectrum experiment is performed on the first quantum bit at each voltage value to obtain the corresponding frequency value.

[0016] Based on the correspondence between the frequency value of the first quantum bit and the voltage value of the fast modulation signal, the first change relationship or the second change relationship is plotted.

[0017] Preferably, obtaining the amplitude of the first waveform includes:

[0018] A state swap is performed on the first qubit and the second qubit using a UZ pulse, and a state swap effect diagram is obtained. The state swap effect diagram includes the relationship between the state swap effect and the amplitude of the UZ pulse, wherein the UZ pulse includes a third waveform with a positive amplitude.

[0019] The amplitude of the UZ pulse corresponding to the state exchange effect satisfying the first set condition is obtained from the state exchange effect diagram and used as the amplitude of the first waveform.

[0020] Preferably, the state-swapping effect diagram includes the relationship between the probability of the second qubit being in the ground state and the amplitude of the UZ pulse.

[0021] Secondly, this application proposes a method for obtaining a pulse for a two-qubit quantum logic gate, wherein the pulse includes a first waveform with a positive amplitude and a second waveform with a negative amplitude, and the pulse is used for state exchange between a first qubit and a second qubit, comprising:

[0022] The amplitude of the first waveform is continuously changed, and the corresponding first pulse is obtained by the pulse acquisition method for realizing state exchange between two qubits proposed in the first aspect of this application. The first pulse is then used to perform state exchange on the first qubit and the second qubit respectively, and the correspondence between the state exchange effect and each first pulse is obtained.

[0023] The first pulse corresponding to the state exchange effect reaching the second set condition is used as the pulse for the two-bit quantum logic gate.

[0024] Thirdly, this application provides a method for executing a two-qubit quantum logic gate, comprising:

[0025] The second pulse for a two-bit quantum logic gate is obtained using the pulse acquisition method for a two-bit quantum logic gate provided in the second aspect of this application;

[0026] Both the first and second qubits are set to the excited state;

[0027] The second pulse is applied to the first qubit to achieve state exchange between the first qubit and the second qubit.

[0028] Fourthly, this application provides a storage medium storing a computer program thereon, which, when executed, enables the acquisition method for obtaining the pulse that realizes state exchange between two qubits as described in the first aspect of this application.

[0029] Fifthly, this application provides a device for acquiring a pulse for state exchange between two qubits, the pulse comprising a first waveform with positive amplitude and a second waveform with negative amplitude, the pulse being used for state exchange between a first qubit and a second qubit, the acquisition device comprising:

[0030] The change relationship acquisition module is configured to set the operating point of the first quantum bit to the degeneracy point, and acquire a first change relationship of the bit frequency of the first quantum bit with the voltage value of the applied positive fast modulation signal and a second change relationship with the voltage value of the applied reverse fast modulation signal.

[0031] A bit frequency acquisition module is configured to acquire the amplitude of the first waveform and acquire the first frequency value of the quantum bit based on the amplitude of the first waveform and the first change relationship.

[0032] The second waveform acquisition module is configured to acquire a first voltage value as the amplitude of the second waveform based on the first frequency value and the second change relationship.

[0033] In a sixth aspect, this application provides a quantum computer, including the pulse acquisition device for realizing state exchange between two qubits as described in the fifth aspect of this application.

[0034] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0035] This invention provides a method for acquiring pulses that enable state exchange between two qubits. The method involves acquiring a first relationship between the bit frequency of the first qubit and the voltage value of an applied positive fast modulation signal, and a second relationship between the bit frequency and the voltage value of an applied negative fast modulation signal. Based on the first relationship, the method acquires the bit frequency corresponding to the amplitude of the first waveform. Based on the acquired bit frequency and the second relationship, the method acquires the amplitude of the second waveform. This ensures that the first and second waveforms of the pulse allow the first qubit to operate at the same bit frequency. The technical solution of this invention achieves pulse acquisition, enabling state exchange between two qubits, and thus allowing for efficient execution of two-qubit logic gates. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a flowchart illustrating the method for obtaining the pulse that realizes state exchange between two qubits according to an embodiment of the present invention.

[0038] Figure 2 This is a schematic diagram of the structure of the device for acquiring the pulse that realizes state exchange between two qubits, provided in an embodiment of the present invention. Detailed Implementation

[0039] The specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. The advantages and features of the present invention will become clearer from the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0040] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0042] As described in the background art, in order to perform a two-bit quantum logic gate operation, it is necessary to obtain a pulse that can perform a state exchange operation. The existing technology directly uses zamp pulses of equal magnitude but opposite signs. During the state exchange, no state exchange occurs in the latter half of the zamp pulse. Therefore, it is necessary to obtain a pulse to realize the state exchange operation between two qubits.

[0043] The core idea of ​​this invention is to obtain a pulse that can realize the state exchange operation between two qubits, so that the obtained pulse can be used to efficiently execute two-bit quantum logic gate operations.

[0044] To achieve the above-mentioned idea, embodiments of the present invention provide a method for obtaining a pulse for state exchange between two qubits. The pulse includes a first waveform with positive amplitude and a second waveform with negative amplitude. The pulse is used for state exchange between a first qubit and a second qubit. (See reference...) Figure 1 , Figure 1This is a flowchart illustrating the method for obtaining the pulse for state exchange between two qubits according to an embodiment of the present invention. (See attached diagram.) Figure 1 ,from Figure 1 As can be seen from this, the acquisition method includes:

[0045] Step S102: Set the operating point of the first qubit to the degeneracy point, and obtain the first relationship between the bit frequency of the first qubit and the voltage value of the applied positive fast modulation signal and the second relationship between the bit frequency and the voltage value of the applied reverse fast modulation signal.

[0046] Step S104: Obtain the amplitude of the first waveform, and obtain the first frequency value of the first quantum bit based on the amplitude of the first waveform and the first change relationship;

[0047] Step S106: Obtain the first voltage value as the amplitude of the second waveform based on the first frequency value and the second change relationship.

[0048] In this embodiment, both the first and second qubits are disposed on a quantum chip. Other qubits may also be disposed on the quantum chip. All qubits are coupled to a first control signal transmission line (XY line) and a second control signal transmission line (Z line). The first control signal transmission line provides a first control signal including a qubit modulation signal, which is used to control the change of the quantum state of the qubit. The second control signal transmission line provides a second control signal including a DC bias signal and a fast modulation signal (AC), both of which can modulate the frequency of the target qubit. The qubit is also coupled to a resonant cavity. The resonant frequency of the resonant cavity shifts according to the quantum state of the qubit. By applying a readout signal to the resonant cavity, a readout feedback signal transmitted or reflected from the readout cavity can be obtained. The quantum state of the qubit can then be obtained by analyzing the readout feedback signal.

[0049] In large-scale quantum chips, to realize a two-qubit quantum logic gate using state exchange effects, the bit frequencies of each qubit need to be distributed in a "...high-low-high-low..." pattern. Typically, the bit frequency values ​​of qubits with lower bit frequency values ​​are fixed, and the two-qubit quantum logic gate is realized by adjusting the bit frequency values ​​of qubits with higher bit frequency values. Specifically, to realize the state exchange between the first qubit and the second qubit in the embodiments of the present invention, the pulse obtained in the embodiments of the present invention can be applied to the first qubit to adjust the bit frequency value of the first qubit to a certain frequency, thereby realizing the state exchange between the first qubit and the second qubit.

[0050] The method for obtaining pulses for state exchange of two qubits provided in this embodiment of the invention, in step S102, the degeneracy point refers to the highest point of the qubit frequency. By setting the qubit frequency to the degeneracy point, it is possible to ensure that the change relationship of the qubit frequency with the applied voltage value of the fast modulation signal is symmetrical about the voltage zero point. However, in reality, due to the manufacturing process of quantum chips, it is difficult to ensure that the obtained change relationship is strictly symmetrical about the voltage zero point. By obtaining the first change relationship of the first qubit frequency with the applied positive fast modulation signal voltage value and the second change relationship with the applied negative fast modulation signal voltage value, the qubit frequency can be obtained based on the amplitude of the first waveform and the first change relationship, and the amplitude of the second waveform can be obtained based on the qubit frequency and the second change relationship. This ensures that the first waveform and the second waveform of the obtained pulse can adjust the frequency of the first qubit to the same level, thereby enabling the state exchange process to proceed smoothly. This method can be used to efficiently execute two-qubit quantum logic gate operations.

[0051] In step S104, the amplitude of the first waveform is set empirically, that is, the bit frequency value of the first qubit is adjusted to a suitable value. It should be noted that a pulse that enables the first qubit and the second qubit to exchange states does not necessarily mean that it can be used to execute a two-qubit quantum logic gate. The effect of the state exchange needs to be observed experimentally before the specific amplitude of the first waveform that can be used to execute a two-qubit logic gate is determined. The purpose of this embodiment is only to obtain a pulse that can realize the state exchange between two qubits. Therefore, the amplitude of the first waveform is not specifically limited here.

[0052] In step S104, obtaining the first frequency value of the first quantum bit based on the amplitude of the first waveform and the first change relationship specifically involves finding, from the first change relationship and the amplitude of the first waveform, the bit frequency of the quantum bit is the first frequency value when the voltage value of the fast modulation signal is the amplitude of the first waveform.

[0053] In step S106, obtaining the first voltage value as the amplitude of the second waveform based on the first frequency value and the second change relationship specifically involves finding the first voltage value of the fast modulation signal corresponding to the second change relationship based on the obtained first frequency value, and using the first voltage value of the applied reverse fast modulation signal as the amplitude of the second waveform.

[0054] The method for obtaining a pulse to realize state exchange between two qubits provided in this embodiment of the invention can obtain a pulse to realize state exchange between the first qubit and the second qubit, and can then be used to subsequently realize a two-qubit quantum logic gate.

[0055] In some embodiments, obtaining the first relationship between the bit frequency of the first qubit and the voltage value of the applied forward fast modulation signal, and the second relationship between the bit frequency and the voltage value of the applied reverse fast modulation signal, includes:

[0056] The voltage value of the forward fast modulation signal or the voltage value of the reverse fast modulation signal applied to the first qubit are continuously changed, and a Ramsey experiment is performed on the first qubit at each voltage value to obtain the corresponding frequency value.

[0057] Based on the correspondence between the frequency value of the first quantum bit and the voltage value of the fast modulation signal, the first change relationship or the second change relationship is plotted.

[0058] The first relationship between the bit frequency of the first qubit and the applied positive fast modulation signal and the applied negative fast modulation signal were obtained through the Ramsey experiment. By obtaining the first relationship and the second relationship, the method for obtaining the pulse that realizes the state exchange between two qubits can be implemented.

[0059] In other embodiments, other methods may be used to obtain the first change relationship and the second change relationship. In these embodiments, step S102 specifically includes:

[0060] The voltage value of the reverse fast modulation signal applied to the first quantum bit is continuously changed, and an energy spectrum experiment is performed on the first quantum bit at each voltage value to obtain the corresponding frequency value.

[0061] Based on the correspondence between the frequency value of the first quantum bit and the voltage value of the fast modulation signal, the first change relationship or the second change relationship is plotted.

[0062] The first change and the second change relationship are obtained through the energy spectrum experiment to realize the method for obtaining the pulse that realizes the state exchange between two qubits.

[0063] In step S104, obtaining the amplitude of the first waveform includes:

[0064] A state swap is performed on the first qubit and the second qubit using a UZ pulse, and a state swap effect diagram is obtained. The state swap effect diagram includes the relationship between the state swap effect and the amplitude of the UZ pulse.

[0065] The amplitude of the UZ pulse corresponding to the state exchange effect satisfying the first set condition is obtained from the state exchange effect diagram and used as the amplitude of the first waveform.

[0066] The UZ pulse includes a third waveform with a positive amplitude, which can adjust the frequency of the first qubit to realize the state exchange between the first qubit and the second qubit. The relationship between the state exchange effect and the amplitude of the third waveform is obtained. When performing the state exchange between |11> and |20>, the state exchange effect can be represented by the probability that the second qubit is in the ground state. Specifically, the state exchange effect can be determined according to the type of state exchange performed, without specific limitations. The amplitude of the third waveform corresponding to the state exchange effect satisfying the first set condition is obtained. The first set condition can be, for example, the probability that the second qubit is in the ground state is less than 1% or other values, without specific limitations. The first set condition can be set by the user according to the type of state exchange performed and the required precision.

[0067] By performing state swapping on the first qubit and the second qubit using the UZ pulse and obtaining the state swapping effect diagram, the amplitude of the first waveform can be obtained. Through the state swapping effect diagram of the UZ pulse, the amplitude of the first waveform that can achieve state swapping within a certain range can be preliminarily determined.

[0068] In summary, this invention provides a method for obtaining a pulse for state exchange between two qubits. The pulse includes a first waveform with a positive amplitude and a second waveform with a negative amplitude. The pulse is used for state exchange between a first qubit and a second qubit. The method includes: setting the operating point of the first qubit to its degeneracy point; obtaining a first relationship between the bit frequency of the first qubit and the voltage value of an applied positive fast modulation signal, and a second relationship between the bit frequency and the voltage value of an applied negative fast modulation signal; obtaining the amplitude of the first waveform; obtaining a first frequency value of the first qubit based on the amplitude of the first waveform and the first relationship; and obtaining a first voltage value as the amplitude of the second waveform based on the first frequency value and the second relationship. The pulse obtained by the technical solution of this application can realize state exchange between two qubits for use in two-qubit logic gate operations.

[0069] Based on the same inventive concept, this application also provides a method for obtaining a pulse for a two-qubit quantum logic gate, wherein the pulse includes a first waveform with a positive amplitude and a second waveform with a negative amplitude, and the pulse is used for state exchange between a first qubit and a second qubit, comprising:

[0070] The amplitude of the first waveform is continuously changed, and the corresponding first pulse is obtained by the pulse acquisition method for realizing state exchange between two qubits provided in the embodiment of the present invention. The first pulse is used to perform state exchange on the first qubit and the second qubit respectively, and the correspondence between the state exchange effect and each first pulse is obtained.

[0071] The first pulse corresponding to the state exchange effect reaching the second set condition is used as the pulse for the two-bit quantum logic gate.

[0072] By changing the amplitude of the first pulse and obtaining the corresponding first pulse, the state of the first quantum bit and the second quantum bit are swapped respectively, and the state swapping effect diagram is obtained. The first pulse corresponding to the state swapping effect reaching the second set condition is used to execute a two-bit quantum logic gate.

[0073] For example, when executing a CZ gate, a pulse capable of state swapping is needed. Typically, a state swap between |11> and |20> is used to execute the CZ gate. The state swapping effect is described by the probability that the second qubit is in its ground state. It is necessary to obtain the correspondence between the probability of the second qubit being in its ground state in each state swapping experiment and each of the first pulses. The first pulse corresponding to when the probability of the second qubit being in its ground state is less than 1% is obtained, and the two-qubit quantum logic gate is executed using the first pulse. The two-qubit logic gate includes, but is not limited to, CNOT gates, SWAP gates, and CZ gates. In this embodiment, the two-qubit quantum logic gate is a CZ gate.

[0074] Based on the same inventive concept, embodiments of the present invention also provide a method for executing a two-qubit quantum logic gate, comprising:

[0075] The method for obtaining a pulse for a two-bit quantum logic gate provided in this embodiment of the invention is used to obtain a second pulse for a two-bit quantum logic gate;

[0076] Both the first and second qubits are set to the excited state;

[0077] The second pulse is applied to the first qubit to achieve state exchange between the first qubit and the second qubit.

[0078] Based on the same inventive concept, embodiments of the present invention also provide a device for acquiring a pulse for state exchange between two qubits, the pulse comprising a first waveform with positive amplitude and a second waveform with negative amplitude, the pulse being used for state exchange between a first qubit and a second qubit, the acquisition device comprising:

[0079] The change relationship acquisition module is configured to set the operating point of the first quantum bit to the degeneracy point, and acquire a first change relationship of the bit frequency of the first quantum bit with the voltage value of the applied positive fast modulation signal and a second change relationship with the voltage value of the applied reverse fast modulation signal.

[0080] A bit frequency acquisition module is configured to acquire the amplitude of the first waveform and acquire the first frequency value of the quantum bit based on the amplitude of the first waveform and the first change relationship.

[0081] The second waveform acquisition module is configured to acquire a first voltage value as the amplitude of the second waveform based on the first frequency value and the second change relationship.

[0082] It is understood that the change relationship acquisition module, the bit frequency acquisition module, and the second waveform acquisition module can be implemented in a single device, or any one of these modules can be split into multiple sub-modules. Alternatively, at least part of the functionality of one of these modules can be combined with at least part of the functionality of another module and implemented in a single functional module. According to embodiments of the present invention, at least one of the change relationship acquisition module, the bit frequency acquisition module, and the second waveform acquisition module can be at least partially implemented as a hardware circuit, such as a Field Programmable Gate Array (FPGA), a Programmable Logic Array (PLA), a System-on-Chip, a System-on-Substrate, a System-on-Package, an Application-Specific Integrated Circuit (ASIC), or can be implemented in hardware or firmware in any other reasonable manner of integrating or packaging the circuit, or in a suitable combination of software, hardware, and firmware implementations. Alternatively, at least one of the change relationship acquisition module, the bit frequency acquisition module, and the second waveform acquisition module can be at least partially implemented as a computer program module, which, when run by a computer, can execute the functions of the corresponding module.

[0083] Based on the same inventive concept, this invention also provides a quantum computer, including the device for acquiring the pulse that realizes the state exchange between two qubits as described in this invention.

[0084] Based on the same inventive concept, this embodiment of the invention also provides a storage medium storing a computer program thereon. When the computer program is executed, it can implement the method for obtaining the pulse that realizes the state exchange between two qubits provided in this embodiment of the invention.

[0085] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," or "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0086] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A method for obtaining a pulse for state exchange between two qubits, the pulse comprising a first waveform with positive amplitude and a second waveform with negative amplitude, the pulse being used for state exchange between a first qubit and a second qubit, characterized in that, The acquisition method includes: Set the operating point of the first qubit to the degeneracy point, and obtain a first relationship between the bit frequency of the first qubit and the voltage value of the applied positive fast modulation signal, and a second relationship between the bit frequency and the voltage value of the applied reverse fast modulation signal. The amplitude of the first waveform is obtained, and the first frequency value of the first quantum bit is obtained based on the amplitude of the first waveform and the first change relationship. The first voltage value is obtained as the amplitude of the second waveform based on the first frequency value and the second change relationship.

2. The acquisition method as described in claim 1, characterized in that, The process of obtaining the first relationship between the bit frequency of the first quantum bit and the voltage value of the applied positive fast modulation signal, and the second relationship between the bit frequency and the voltage value of the applied negative fast modulation signal, includes: The voltage value of the forward fast modulation signal or the voltage value of the reverse fast modulation signal applied to the first qubit are continuously changed, and a Ramsey experiment is performed on the first qubit at each voltage value to obtain the corresponding frequency value. Based on the correspondence between the frequency value of the first quantum bit and the voltage value of the fast modulation signal, the first change relationship or the second change relationship is plotted.

3. The acquisition method as described in claim 1, characterized in that, The process of obtaining the first relationship between the bit frequency of the first quantum bit and the voltage value of the applied positive fast modulation signal, and the second relationship between the bit frequency and the voltage value of the applied negative fast modulation signal, includes: The voltage value of the positive fast modulation signal or the voltage value of the negative fast modulation signal applied to the first quantum bit are continuously changed, and an energy spectrum experiment is performed on the first quantum bit at each voltage value to obtain the corresponding frequency value. Based on the correspondence between the frequency value of the first quantum bit and the voltage value of the fast modulation signal, the first change relationship or the second change relationship is plotted.

4. The acquisition method as described in claim 1, characterized in that, Obtaining the amplitude of the first waveform includes: A state swap is performed on the first qubit and the second qubit using a UZ pulse, and a state swap effect diagram is obtained. The state swap effect diagram includes the relationship between the state swap effect and the amplitude of the UZ pulse, wherein the UZ pulse includes a third waveform with a positive amplitude. The amplitude of the UZ pulse corresponding to the state exchange effect satisfying the first set condition is obtained from the state exchange effect diagram and used as the amplitude of the first waveform.

5. The acquisition method as described in claim 4, characterized in that, The state-swapping effect diagram includes the relationship between the probability of the second qubit being in the ground state and the amplitude of the UZ pulse.

6. A method for obtaining pulses for a two-qubit quantum logic gate, characterized in that, The pulse includes a first waveform with a positive amplitude and a second waveform with a negative amplitude. The pulse is used for state exchange between a first qubit and a second qubit, including: The amplitude of the first waveform is continuously changed, and the corresponding first pulse is obtained by the pulse acquisition method for realizing state exchange between two qubits as described in any one of claims 1 to 5. The first pulse is used to perform state exchange on the first qubit and the second qubit respectively, and the correspondence between the state exchange effect and each first pulse is obtained. The first pulse corresponding to the state exchange effect reaching the second set condition is used as the pulse for the two-bit quantum logic gate.

7. A method for executing a two-qubit quantum logic gate, characterized in that, include: The second pulse for a two-bit quantum logic gate is obtained using the acquisition method described in claim 6; Both the first and second qubits are set to the excited state; The second pulse is applied to the first qubit to achieve state exchange between the first qubit and the second qubit.

8. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed, it can implement the method for obtaining the pulse that realizes state exchange between two qubits as described in any one of claims 1 to 5.

9. A device for acquiring a pulse for state exchange between two qubits, the pulse comprising a first waveform with positive amplitude and a second waveform with negative amplitude, the pulse being used for state exchange between a first qubit and a second qubit, characterized in that, The acquisition device includes: The change relationship acquisition module is configured to set the operating point of the first quantum bit to the degeneracy point, and acquire a first change relationship of the bit frequency of the first quantum bit with the voltage value of the applied positive fast modulation signal and a second change relationship with the voltage value of the applied reverse fast modulation signal. A bit frequency acquisition module is configured to acquire the amplitude of the first waveform and acquire the first frequency value of the quantum bit based on the amplitude of the first waveform and the first change relationship. The second waveform acquisition module is configured to acquire a first voltage value as the amplitude of the second waveform based on the first frequency value and the second change relationship.

10. A quantum computer, characterized in that, The device includes the pulse acquisition device for realizing state exchange between two qubits as described in claim 9.

Images