Rapid initialization method and system for qubit, and superconducting quantum computer

Abstract

Disclosed in the present invention are a rapid initialization method and system for a qubit and a superconducting quantum computer. The method comprises: calibrating the frequency of a readout cavity for a qubit, frequencies of excited states, a Rabi oscillation between a ground state and a first excited state, and a Rabi oscillation between the excited states; calibrating transverse field driving frequencies of dressed states and transverse field driving frequencies of the excited states; measuring quantum state evolution probabilities under different transverse field driving amplitudes, and determining transverse field driving parameters with the fastest initialization rate; and applying the transverse field driving parameters to corresponding channels to implement rapid initialization of the qubit. The system comprises a waveform generator module, a combiner module, a quantum carrier module and a readout display module. The superconducting quantum computer comprises the system and executes the method. The present disclosure can quickly change the equivalent coupling strength between the qubit and a resonant cavity, and uses the extremely high photon dissipation rate of the resonant cavity to build a rapid dissipation channel, thereby implementing rapid initialization of a Fluxonium qubit.

Description

A method, system and superconducting quantum computer for fast initialization of qubits Technical Field

[0001] This invention relates to the quantum field, and more particularly to a method, system, and superconducting quantum computer for rapid initialization of qubits. Background Technology

[0002] Superconducting quantum computers leverage quantum properties such as quantum superposition and entanglement to achieve exponential speedups compared to conventional computers when processing complex computations. As the fundamental unit of superconducting quantum computing, the design of the qubit plays a crucial role in the performance and scalability of the computer. Commonly used qubit types include transmon, Fluxonium, and Xmon.

[0003] The energy difference between the energy levels of a Fluxonium qubit exhibits a nonlinear relationship with changes in external magnetic flux. This nonlinearity can be utilized to optimize the geometry and material parameters of the superconducting circuit during Fluxonium design. Combined with external magnetic field manipulation techniques, this effectively suppresses magnetic flux quantum fluctuations, improving the coherence and stability of the qubit. Furthermore, the excellent anharmonicity of Fluxonium qubits makes them less susceptible to excitation to high-energy bands during gate operations. Typically, the coherence time of Fluxonium qubits can reach the millisecond level. Manipulating Fluxonium qubits for scientific experiments is a complex and precise task. In this process, qubit initialization is one of the most crucial steps.

[0004] By properly initializing qubits, we can place them in the desired initial state, providing a reliable foundation for subsequent operations and measurements. This accurate initialization not only helps maintain the consistency and reproducibility of experimental results but also minimizes the impact of external disturbances, improving the precision and reliability of the experiment.

[0005] Current methods for initializing qubits include several approaches. One involves using energy relaxation to allow the qubit to decay to its ground state. However, for Fluxonium qubits, the long relaxation time means that decaying to the ground state takes a considerable amount of time. Another method involves adding dissipative components during the design and fabrication of superconducting quantum chips to quickly place the qubit into its ground state. However, this increases the manufacturing burden of Fluxonium qubits and negatively impacts their performance. Finally, some methods adjust the external magnetic flux to alter the qubit's energy level structure and induce a ground state. However, introducing external magnetic flux introduces magnetic noise, which can increase errors during the qubit initialization process.

[0006] In summary, although there are various methods for initializing qubits, none of them can be directly applied to initializing Fluxonium qubits. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by proposing a method, system, and superconducting quantum computer for rapid initialization of qubits.

[0008] To achieve the above objectives, the present invention employs the following technical solution: a method for fast initialization of quantum bits, comprising:

[0009] S100, calibrates the quantum bit readout cavity frequency, the frequency of the excited state, the Rabi oscillation between the ground state and the first excited state, and the Rabi oscillation between the excited states;

[0010] S200, calibrate the transverse field driving frequency of the adorned state and the transverse field driving frequency of the excited state to obtain the correspondence between the transverse field driving frequency and the transverse field driving amplitude.

[0011] S300, measure the quantum state ground state evolution probability under different transverse field driving amplitudes, and combine the correspondence between transverse field driving frequency and transverse field driving amplitude in S200 to determine the transverse field driving parameter with the fastest initialization rate;

[0012] S400 applies the transverse field driving parameters obtained in S300 to the corresponding channel to achieve rapid initialization of the qubit.

[0013] Optionally, in step S100, the reading cavity frequency of the qubit is calibrated by a calibration device, the frequencies of the first excited state and the second excited state of the qubit are calibrated, the Rabi oscillation between the ground state and the first excited state of the qubit is calibrated, and the Rabi oscillation between the first excited state and the second excited state of the qubit is calibrated.

[0014] Optionally, step S200 includes:

[0015] S210, completes the transverse field drive frequency calibration of the first and third adorned states;

[0016] S220, complete the transverse field driving frequency calibration of the first and second excited states of the qubit.

[0017] Optionally, step S210 includes:

[0018] S211, Prepare the qubit to the first decorated state;

[0019] S212, based on the first adorned state, with a fixed transverse driving time, apply transverse driving fields of different frequencies and amplitudes on the XY channels;

[0020] S213, obtain the energy spectrum of the quantum state as a function of frequency and driving amplitude ratio;

[0021] S214, Fit the first spectral line with the highest probability of the qubit being in the ground state to obtain the transverse field driving frequency of the third adorned state and the first adorned state and the transverse field driving amplitude corresponding to the transverse field driving frequency.

[0022] Optionally, step S220 includes:

[0023] S221, the qubit is excited from the first excited state to the second excited state;

[0024] S222, The transverse field driving frequency and transverse field driving amplitude of the first and third adorned states fitted in step S214 are applied to the XY channel of the qubit.

[0025] S223, obtain the transverse field driving frequency of the qubit between the first excited state and the second excited state in different groups, and

[0026] Energy spectra of the first and third decorated states under transverse field driving amplitudes in different groups;

[0027] S224, Fit the second spectral line where the qubit has the highest probability of being in the ground state to obtain the transverse field driving frequency between the first excited state and the second excited state, and the transverse field driving amplitude of the corresponding first and third decorated states.

[0028] Optionally, step S300 includes:

[0029] S310, obtain the transverse field driving frequency of the first and third adorned states corresponding to the transverse field driving amplitude of the first and third adorned states of different groups, as well as the transverse field driving frequency between the first and second excited states.

[0030] S320, to measure the quantum state ground state evolution probability of different groups of transverse field driving frequency and amplitude;

[0031] S321, construct the quantum system state evolution equation and iteratively solve for coupling parameters and decay rate;

[0032] S322, obtain the transverse field driving amplitude and transverse field driving frequency of the first and third adorned states corresponding to the maximum decay rate, and

[0033] The transverse driving frequency between the first and second excited states.

[0034] A fast initialization system for qubits, used to perform any of the fast initialization methods described above, comprising:

[0035] A waveform generator module, which can apply driving signals or transverse field driving through multiple XY channels respectively;

[0036] A combiner module, which is used to combine drive signals or transverse field drives applied to multiple XY channels into a single channel;

[0037] A quantum carrier module is connected to both the combiner module and the waveform generator module. The combiner module applies a transverse field driving signal to the quantum carrier module through the XY channel.

[0038] A reading and display module is connected to the quantum carrier module.

[0039] Optionally, both the combiner module and the waveform generator module are connected to the quantum carrier module via attenuators and filters.

[0040] A superconducting quantum computer with rapid initialization of qubits includes any of the above-mentioned rapid initialization systems and executes any of the above-mentioned rapid initialization methods.

[0041] The present invention has the following beneficial effects:

[0042] 1. This disclosure calibrates the transverse field driving frequency of the adorned state and excited state by first calibrating the frequency and Rabi oscillation to obtain the correspondence between the transverse field driving frequency and the transverse field driving amplitude. Then, the transverse field driving parameter with the fastest initialization rate is determined according to the quantum state evolution probability. After the transverse field driving parameter is entered, the equivalent coupling strength between the quantum bit and the resonant cavity can be rapidly changed. By utilizing the extremely strong photon dissipation rate of the resonant cavity, a fast dissipation channel is constructed to realize the rapid initialization of the Fluxonium quantum bit.

[0043] 2. Compared to existing methods that utilize the energy relaxation of the bit itself to decay to the ground state, introduce dissipative components during chip design and fabrication, or adjust external magnetic flux signals, this disclosure significantly shortens the initialization time and greatly improves experimental efficiency. Furthermore, it eliminates the need for dissipative components in chip design, reducing the burden on the manufacturing process. In addition, the absence of a magnetic flux signal avoids low-frequency noise disturbances to other bits, improving experimental accuracy and saving energy. Attached Figure Description

[0044] Figure 1 is a flowchart of the fast initialization method;

[0045] Figure 2 is a flowchart of the transverse field driven calibration process for the third and first adorned states;

[0046] Figure 3 shows the waveforms of each channel during transverse field drive frequency calibration between the third and first adorned states in a single cycle.

[0047] Figure 4 is a flowchart of the transverse field driven calibration process for the first and second excited states;

[0048] Figure 5 shows the waveforms of each channel during transverse field driving frequency calibration for the first and second excited states of a single periodic state.

[0049] Figure 6 is a flowchart for determining the transverse field driving amplitude;

[0050] Figure 7 shows the architecture diagram of the rapid initialization system.

[0051] Legend: 1. Waveform generator module; 2. Combiner module; 3. Quantum carrier module; 4. Reading and display module; 5. Attenuator; 6. Filter. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0053] Please refer to Figure 1, which provides an embodiment of this disclosure: a fast initialization method for qubits, specifically a fast initialization method for Fluxonium qubits. First, Fluxonium is explained as a qubit design based on a superconducting quantum loop, consisting of a superconducting loop composed of Josephson junctions, coupling capacitors, microwave control lines, magnetic flux lines, and a resonant cavity. It features strong nonlinearity, tunability, and low-frequency quantum oscillation. Its energy level structure exhibits very strong nonlinear characteristics, making it highly resistant to external noise, resulting in a long decoherence time, reaching the millisecond level. Because of this long decoherence time, initializing Fluxonium qubits by allowing them to decay to their ground state requires a considerable amount of time. Adding dissipative components during quantum chip design and fabrication is also an option, but for the superconducting loop technology of Fluxonium qubits, adding dissipative components would be burdensome and affect the qubit's performance. Finally, using magnetic flux might introduce additional magnetic flux noise, affecting the error during the initialization process.

[0054] Therefore, in order to minimize or avoid the above problems, this disclosure provides a fast initialization method for quantum bits that are suitable for long energy relaxation times such as Fluxonium, without introducing additional processes at the chip design and fabrication level and without applying low-frequency signals to cause magnetic flux disturbances.

[0055] Specific methods include:

[0056] S100 calibrates the quantum bit readout cavity frequency, the frequency of the excited state, and the Rabi oscillations between the ground state and the excited state, as well as the Rabi oscillations between the excited states. Optionally, the frequency of the quantum bit readout cavity is calibrated using devices such as a vector network analyzer, a microwave source, and an arbitrary waveform generator. In a Fluxonium quantum bit, there is a coupling capacitance between the readout resonant cavity and the quantum bit; the quantum bit state is measured by the frequency change of the readout resonant cavity. Simultaneously, the frequencies of the first and second excited states of the quantum bit, the Rabi oscillations between the ground state and the first excited state, and the Rabi oscillations between the first and second excited states are calibrated using the aforementioned devices. In this invention, the ground state, first excited state, and second excited state of the Fluxonium qubit are considered as |g>, |e>, and |f>, respectively. The photon number Fock state read from the resonant cavity is considered as |0>, |1>, and |2>. The adorned state formed by the large detuning coupling of the ground state or excited state and the photon number Fock state is considered as |g1>, |e0>, and |f0>. Specifically, for easier understanding of the invention, |g1>, |e0>, and |f0> are defined as the first adorned state, the second adorned state, and the third adorned state, respectively. It should be noted that the main function of Rabi oscillation is to determine the energy required to transition the qubit from the |g> state to the |e> state and from the |e> state to the |f> state. To explain the modified state, when a quantum system interacts with an external field, the system's Hamiltonian includes the original system's Hamiltonian and the interaction term. The eigenstates of this total Hamiltonian are the modified states. That is, the modified state is a new eigenstate formed jointly by the system and its external environment.

[0057] S200, calibrate the transverse field driving frequency of the decorated state and the transverse field driving frequency of the excited state to obtain the correspondence between the transverse field driving frequency and the transverse field driving amplitude. The specific calibration steps include:

[0058] S210, complete the transverse field driving frequency calibration between the first adorned state |g1> and the third adorned state |f0>;

[0059] S210 includes:

[0060] S211 first prepares the Fluxonium qubit to the first decorated state |g1>;

[0061] S212, based on the first adorned state |g1>, with a fixed transverse driving time, transverse driving fields of different frequencies and amplitudes are applied to the XY channel through an arbitrary waveform generator and a combiner. The XY channel represents a type of quantum operation acting on the qubit, capable of performing specific rotations and transformations on the qubit's state. The XY channel can achieve rotations at different angles on the Bloch sphere of the qubit, thereby changing the qubit's state. The XY channel can be implemented physically; in some embodiments, XY channel operation can be achieved by controlling microwave pulses of the superconducting qubit. In other embodiments, the XY channel can be implemented using a series of quantum logic gates, i.e., a combination of basic quantum logic gates such as Hadamard gates, phase gates, and CNOT gates can be used to implement XY channel operation.

[0062] S213, scan to obtain the energy spectrum of Fluxonium's quantum state as a function of frequency and driving pulse amplitude;

[0063] S214: Fit the first spectral line with the highest probability of the qubit being in the ground state to obtain the transverse field driving frequency of the first adorned state |g1> and the third adorned state |f0> and the corresponding transverse field driving amplitude. This first spectral line is the correspondence between the transverse field driving frequency that can quickly reset the Fluxonium qubit from the first excited state |e> to the ground state |g> and the transverse field driving amplitude of the third adorned state |f0> and the first adorned state |g1>, as shown in Figure 2. For the transverse field driving between the third adorned state |f0> and the first adorned state |g1> with different frequencies and amplitudes, the waveform diagram of each channel in a single cycle is shown in Figure 3. Each channel includes the XY1 channel, the XY3 channel, and the Readin channel.

[0064] S220, complete the transverse field driving frequency calibration between the first excited state |e> and the second excited state |f> of the qubit. Specifically, since the transition frequency of the Fluxonium qubit changes under different transverse field driving amplitudes of the third adorned state |f0> and the first adorned state |g1>, the transverse field driving frequency between the first excited state |e> and the second excited state |f> also changes with the transverse field driving amplitudes of the third adorned state |f0> and the first adorned state |g1>. Therefore, it is necessary to rescan the energy spectrum to complete the calibration of the transverse field driving frequency between the first excited state |e> and the second excited state |f>. Please refer to Figure 4. The specific calibration steps include:

[0065] S221, in addition to applying the normal driving signal to the XY channel using an arbitrary waveform generator, an additional pulse signal is applied to excite the qubit from the first excited state |e> to the second excited state |f>. The length and amplitude of the applied pulse signal can be determined through Rabi oscillation experiments between the first excited state |e> and the second excited state |f> of the Fluxonium qubit. The waveform diagrams for each channel in a single cycle are shown in Figure 5, and will not be elaborated upon here.

[0066] S222, apply the transverse field driving frequency and transverse field driving amplitude of the first adorned state |g1> and the third adorned state |f0> at the fitting point in step S214 to the XY channel of the Fluxonium qubit;

[0067] S223, scan to obtain the transverse field driving frequency of the Fluxonium qubit between the first excited state |e> and the second excited state |f> in different groups, and

[0068] Energy spectra of the first and third adorned states |g1> and |f0> under transverse field driving amplitudes in different groups;

[0069] S224, Fit the second spectral line with the highest probability of the qubit being in the ground state to obtain the transverse field driving frequency between the first excited state |e> and the second excited state |f>, and the corresponding transverse field driving amplitudes of the first decorated state |g1> and the third decorated state |f0>. The second spectral line represents the correspondence between the transverse field driving frequencies of the first excited state |e> and the second excited state |f>, and the transverse field driving amplitudes of the first decorated state |g1> and the third decorated state |f0>, which can be used to quickly initialize the Fluxonium qubit from the first excited state |e>.

[0070] S300, measure the quantum state ground state evolution probability under different transverse field driving amplitudes, and combine the correspondence between transverse field driving frequency and transverse field driving amplitude in S200 to determine the transverse field driving parameter with the fastest initialization rate;

[0071] The specific steps include:

[0072] After determining the correspondence between the transverse field driving frequency and the transverse field driving amplitudes of the third adorned state |f0> and the first adorned state |g1>, the transverse field driving amplitude with the fastest initialization rate is determined.

[0073] S310, obtain the transverse field driving frequency of the first adorned state |g1> and the third adorned state |f0> corresponding to the transverse field driving amplitude of different groups, as well as the transverse field driving frequency between the first excitation state |e> and the second excitation state |f>;

[0074] S320, to measure the quantum state ground state evolution probability of different groups of transverse field driving frequency and amplitude;

[0075] S321, construct the quantum system state evolution equation and iteratively solve for the coupling parameters and decay rate. Specifically, the change in the probability of the quantum system evolving from the initial state |s0> to the state |s> over time can be calculated using the quantum system state evolution equation:

[0076] In the above formula, H is the Hamiltonian of the quantum system, and λ k These are coupling parameters;

[0077] P(s0→s,t): The probability that a quantum system evolves from the initial state |s0> to the target state |s> after time t;

[0078] K, j, m: Different states of a quantum system;

[0079] T jk , The coupling strength or transition probability (evolution matrix) between quantum states j and k (or k and m), where This is the complex conjugate form of the evolution matrix;

[0080] <s|e -iHt |s0>: The amplitude of the initial state |s0> evolving to state |s> over time t under the control of Hamiltonian H;

[0081] <s(t0)|s> The inner product between quantum state s(t0) and |s>;

[0082] The above formula can be used to solve for λ. k The imaginary part of the coupling parameter determines the decay rate of the Fluxonium qubit;

[0083] S322, in this disclosure, the transverse field driving amplitude and frequency of the first and third decorated states corresponding to the maximum decay rate are obtained, as well as the transverse field driving frequency between the first and second excited states. Specifically, the decay rate γ of the Fluxonium qubit from the second excited state |f> to the ground state |g> is defined. k =min(|Im(λ) kBy changing the amplitude of the transverse field drive between the third adorned state |f0> and the first adorned state |g1> of the Fluxonium qubit, and applying the corresponding transverse field drive frequency, the decay rate is calculated. The drive amplitude corresponding to the maximum decay rate is the transverse field drive amplitude with the fastest initialization rate of the Fluxonium qubit. The drive frequencies between the first excited state |e> and the second excited state |f>, and between the third adorned state |f0> and the first adorned state |g1>, are the transverse field drive frequencies that can quickly initialize the Fluxonium qubit, as shown in Figure 6.

[0084] S400, apply the transverse field driving parameters obtained in S300 to the corresponding channel to achieve rapid initialization of the qubit; specifically, after determining the transverse field driving frequency that can rapidly initialize the Fluxonium qubit and the transverse field driving amplitude that can initialize the Fluxonium qubit at the fastest rate, the transverse field driving frequency and transverse field driving amplitude are driven into the resonant cavity through the XY channel.

[0085] This alters the equivalent coupling strength between the qubit and the readout cavity, and constructs a fast dissipation channel through the resonant cavity to achieve rapid qubit initialization. Specifically, a coupling exists between the Fluxonium qubit and its corresponding readout cavity. When an external microwave field, i.e., transverse field driving, is applied and interacts with this coupling, a Raman process is induced. During this process, the qubit can absorb or emit a photon, causing a change in its quantum state. Therefore, in this application, a transverse field driving is achieved by applying a microwave field of specific frequency and amplitude, thereby altering the coupling between the qubit and the readout cavity, resulting in a change in the energy level structure between the qubit and the readout cavity. Utilizing the extremely high photon dissipation rate of the resonant cavity, an energy dissipation channel is constructed for the system, thereby achieving rapid initialization of the Fluxonium qubit.

[0086] Please refer to Figure 7. This disclosure also provides an embodiment: a rapid initialization system for qubits, which is used to perform the above-described rapid initialization method, specifically including:

[0087] Waveform generator module 1, which can be any waveform generator, includes at least four channels, including XY1 channel, XY2 channel, XY3 channel and Readin channel. XY1 channel is used to apply the drive signal, i.e., the driving signal, for normal manipulation of the qubit, such as driving the qubit to the second excited state |f>. XY2 channel is used to apply the transverse field drive between the first excited state |e> and the second excited state |f>. Readin channel is used to read the quantum state.

[0088] Combiner module 2, which can be a three-in-one combiner, can apply the transverse field driving frequency and amplitude of the XY1 channel, XY2 channel and XY3 channel to the XY channel of the quantum bit, thereby changing the coupling between the quantum bit and the resonant cavity, and causing the energy level structure between the quantum bit and the readout cavity to change.

[0089] The reading and display module 4 can optionally be a digital acquisition instrument. The digital acquisition instrument is connected to the quantum carrier module 3, i.e., the Fluxonium quantum bit, through a room temperature amplifier, a low temperature amplifier, a three-section isolator and an infrared filter 6 arranged in sequence, and can acquire and display various parameters of the Fluxonium quantum bit.

[0090] It should be noted that the quantum carrier module 3, i.e., the Fluxonium qubit, consists of a superconducting loop composed of Josephson junctions, coupling capacitors, microwave control lines, magnetic flux lines, and a resonant cavity. Both the combiner module 2 and the waveform generator module 1 are connected to the quantum carrier module 3 via attenuator 5 and filter 6. Attenuator 5 can be used to adjust the signal strength to meet the input requirements of the XY channels. Filter 6 can be used to eliminate noise and interference to select specific quantum states or frequency ranges.

[0091] The present invention also discloses an embodiment of a superconducting quantum computer with rapid initialization of qubits, comprising the rapid initialization system of any of the above and executing the rapid initialization method of any of the above.

[0092] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for fast initialization of qubits, characterized in that, include: S100, calibrates the quantum bit readout cavity frequency, the frequency of the excited state, the Rabi oscillation between the ground state and the first excited state, and the Rabi oscillation between the excited states; S200, calibrate the transverse field driving frequency of the adorned state and the transverse field driving frequency of the excited state to obtain the correspondence between the transverse field driving frequency and the transverse field driving amplitude. S300, measure the quantum state ground state evolution probability under different transverse field driving amplitudes, and combine the correspondence between transverse field driving frequency and transverse field driving amplitude in S200 to determine the transverse field driving parameter with the fastest initialization rate; S400 applies the transverse field driving parameters obtained in S300 to the corresponding channel to achieve rapid initialization of the qubit.

2. The method for fast initialization of qubits according to claim 1, characterized in that, In step S100, the reading cavity frequency of the qubit is calibrated by a calibration device, the frequencies of the first excited state and the second excited state of the qubit are calibrated, the Rabi oscillation between the ground state and the first excited state of the qubit is calibrated, and the Rabi oscillation between the first excited state and the second excited state of the qubit is calibrated.

3. The method for fast initialization of qubits according to claim 1, characterized in that, Step S200 includes: S210, completes the transverse field drive frequency calibration of the first and third adorned states; S220, complete the transverse field driving frequency calibration of the first and second excited states of the qubit.

4. The method for fast initialization of qubits according to claim 3, characterized in that, Step S210 includes: S211, Prepare the qubit to the first decorated state; S212, based on the first adorned state, with a fixed transverse driving time, apply transverse driving fields of different frequencies and amplitudes on the XY channels; S213, obtain the energy spectrum of the quantum state as a function of frequency and driving amplitude ratio; S214, Fit the first spectral line with the highest probability of the qubit being in the ground state to obtain the transverse field driving frequency of the third adorned state and the first adorned state and the transverse field driving amplitude corresponding to the transverse field driving frequency.

5. The method for fast initialization of qubits according to claim 1, characterized in that, Step S220 includes: S221, the qubit is excited from the first excited state to the second excited state; S222, The transverse field driving frequency and transverse field driving amplitude of the first and third adorned states fitted in step S214 are applied to the XY channel of the qubit. S223, obtain the transverse field driving frequency of the qubit between the first excited state and the second excited state in different groups, and Energy spectra of the first and third decorated states under transverse field driving amplitudes in different groups; S224, Fit the second spectral line where the qubit has the highest probability of being in the ground state to obtain the transverse field driving frequency between the first excited state and the second excited state, and the transverse field driving amplitude of the corresponding first and third decorated states.

6. The method for fast initialization of qubits according to claim 1, characterized in that, Step S300 includes: S310, obtain the transverse field driving frequency of the first and third adorned states corresponding to the transverse field driving amplitude of the first and third adorned states of different groups, as well as the transverse field driving frequency between the first and second excited states. S320, to measure the quantum state ground state evolution probability of different groups of transverse field driving frequency and amplitude; S321, construct the quantum system state evolution equation and iteratively solve for coupling parameters and decay rate; S322, obtain the transverse field driving amplitude and transverse field driving frequency of the first and third adorned states corresponding to the maximum decay rate, and The transverse driving frequency between the first and second excited states.

7. A fast initialization system for qubits, used to execute the fast initialization method of any one of claims 1-6, characterized in that, include: A waveform generator module, which can apply driving signals or transverse field driving through multiple XY channels respectively; A combiner module, which is used to combine drive signals or transverse field drives applied to multiple XY channels into a single channel; A quantum carrier module is connected to both the combiner module and the waveform generator module. The combiner module applies a transverse field driving signal to the quantum carrier module through the XY channel. A reading and display module is connected to the quantum carrier module.

8. The rapid initialization system for qubits according to claim 7, characterized in that, Both the combiner module and the waveform generator module are connected to the quantum carrier module via attenuators and filters.

9. A superconducting quantum computer with rapid initialization of qubits, characterized in that, The system includes the rapid initialization system of any one of claims 7-8 and performs the rapid initialization method of any one of claims 1-6.

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