Initialization method of quantum bit reading cavity

Abstract

The present invention provides a method for initializing a quantum bit reading cavity, comprising: obtaining an initialization waveform for reducing the number of photons in a reading cavity; and applying the initialization waveform to the reading cavity to initialize the reading cavity. The technical solution of the present invention utilizes the initialization waveform to rapidly fill and empty the reading cavity with photons, shortening the time required to initialize the reading cavity compared to spontaneous photon emission. Pre-measurement using the initialization waveform avoids the influence of the AC stack effect and eliminates the influence of system thermal excitation on experimental results, thereby improving the accuracy of quantum operations.

Description

Technical Field

[0001] The present invention belongs to the field of quantum computing technology, and in particular relates to a method and device for initializing a quantum bit reading cavity, and a readable storage medium. Background Art

[0002] After completing a read operation, the quantum bit needs to completely dissipate the photons in the reading cavity before the next read operation. The general method is to wait for a period of time for the photons to spontaneously radiate, which is a time-consuming method.

[0003] In addition, during the execution of quantum bit operations, in order to eliminate the influence of thermal excitation of the system, a pre-measurement is usually performed before the quantum bit operation is executed. All experimental data of the quantum bit state in the excited state during the pre-measurement process are discarded to ensure the accuracy of the entire subsequent quantum bit operation. However, the problem with this approach is that the pre-measurement process will inject a large number of photons into the reading cavity. If the quantum bit is used directly after the pre-measurement, the large number of residual photons in the reading cavity will cause the quantum bit to be in a quantum bit frequency fluctuation induced by the AC stack effect and an additional decoherence state. If the photons in the reading cavity are spontaneously radiated, the quantum bit will return to the thermal equilibrium state, and the pre-measurement will be meaningless.

[0004] Therefore, it is necessary to propose an initialization method for the quantum bit reading cavity so as to reduce the number of photons in the quantum bit reading cavity to a desired level in a relatively short time.

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

[0006] The object of the present invention is to provide a method for initializing a quantum bit reading cavity, which is used to solve the problem of slow emptying of photons in the reading cavity through spontaneous photon radiation.

[0007] To achieve the above objectives, in a first aspect, the present invention provides a method for initializing a quantum bit reading cavity, comprising:

[0008] Acquire an initialization waveform, wherein the initialization waveform is composed of a plurality of waveforms and at least includes a waveform with a negative amplitude and a waveform with a positive amplitude spliced in sequence;

[0009] The initialization waveform is applied to a reading cavity to initialize the reading cavity.

[0010] Preferably, the initialization waveform includes a first waveform, a second waveform and a third waveform spliced in sequence in time, wherein the second waveform has a negative amplitude, the third waveform has a positive amplitude, the time length of the first waveform is T1, and the amplitude is the first amplitude, the time length of the second waveform is T2, and the amplitude is the second amplitude, the time length of the third waveform is T3, and the amplitude is the third amplitude, and the first waveform, the second waveform and the third waveform spliced in time sequence are used to reduce the number of photons in the reading cavity.

[0011] Preferably, the first waveform is obtained by:

[0012] Set the value of T1;

[0013] performing a single-shot read measurement without pre-measurement on a qubit coupled to the read cavity to obtain an amplitude of a read pulse of the qubit;

[0014] determining the first amplitude based on the amplitude of the read pulse;

[0015] The first waveform is determined based on the T1 and the first amplitude.

[0016] Preferably, the second waveform and the third waveform are obtained by:

[0017] Set the values of T2 and T3;

[0018] Adjusting the values of the second amplitude and the third amplitude, and obtaining the number of residual photons in the reading cavity, so that the number of residual photons meets a preset requirement;

[0019] The second waveform and the third waveform are determined based on the values of T2, T3, the second amplitude, and the third amplitude.

[0020] Preferably, adjusting the values of the second amplitude and the third amplitude, and obtaining the number of residual photons in the reading cavity so that the number of residual photons meets a preset requirement, includes:

[0021] Performing a single-shot read measurement without pre-measurement on a quantum bit coupled to the read cavity, and obtaining a fidelity of the single-shot read measurement result without pre-measurement as a first fidelity;

[0022] Setting the amplitudes of the second amplitude and the third amplitude, applying the initialization waveform to the reading cavity, performing reading within the existence time of the first amplitude, and obtaining the fidelity of the reading result as the second fidelity;

[0023] Performing a Ramsey experiment on the quantum bit to obtain the number of residual photons in the reading cavity;

[0024] Determining whether the residual photon number and the difference between the first fidelity and the second fidelity meet a preset condition; if so, the amplitude of the second amplitude and the amplitude of the third amplitude meet the requirement;

[0025] If not, the second amplitude and the third amplitude are updated, and the process returns to applying the initialization waveform to the reading cavity, performing reading within the first amplitude existence time, and obtaining a second fidelity for the reading result.

[0026] Preferably, the preset conditions include:

[0027] The residual photon number is less than 0.01;

[0028] A difference between the first fidelity and the second fidelity is less than 1.5%.

[0029] Preferably, before performing the Ramsey experiment on the quantum bit, the method further includes:

[0030] Calibrate the delay of the bit state control signal line coupled to the quantum bit and the read pulse signal line coupled to the read cavity.

[0031] Preferably, obtaining the number of residual photons in the reading cavity includes:

[0032] obtaining a dissipation rate of the reading cavity;

[0033] Obtaining a relaxation time of the quantum bit;

[0034] The results of the Ramsey experiment were used to fit the formula:

[0035]

[0036] Wherein, Γ2 is the inverse of the relaxation time, Δ is the Ramsey detuning, χ is the dispersion shift, κ is the dissipation rate, and n0 is the number of residual photons;

[0037] The residual photon number is obtained according to the fitting result.

[0038] Preferably, obtaining the dissipation rate of the reading cavity includes:

[0039] applying a read pulse to the read cavity;

[0040] applying an excitation signal to the quantum bit;

[0041] Obtaining a relationship between a bit frequency of the quantum bit and time;

[0042] The dissipation rate of the reading cavity is obtained based on the relationship between the bit frequency and time.

[0043] In a second aspect, the present invention provides an initialization device for a quantum bit reading cavity, comprising:

[0044] An initialization waveform acquisition module is used to acquire an initialization waveform, wherein the initialization waveform is composed of a plurality of waveforms and at least includes a waveform with a negative amplitude and a waveform with a positive amplitude spliced in sequence;

[0045] The initialization waveform applying module is used to apply the initialization waveform to a reading cavity to complete the initialization of the reading cavity.

[0046] In a third aspect, the present invention provides a readable storage medium having a computer program stored thereon, which, when executed, can implement the method for initializing the quantum bit reading cavity provided in the first aspect of the present invention.

[0047] In a fourth aspect, the present invention provides a quantum computer, comprising the initialization device for the quantum bit reading cavity provided in the second aspect of the present invention.

[0048] In a fifth aspect, the present invention provides a single-shot reading measurement method with pre-measurement, comprising:

[0049] Applying an initialization waveform to a reading cavity coupled to the quantum bit, wherein the initialization waveform is composed of a plurality of waveforms and includes at least a waveform with a negative amplitude and a waveform with a positive amplitude that are sequentially spliced;

[0050] A rectangular wave is applied to the reading cavity.

[0051] In a sixth aspect, the present invention provides a single-shot reading measurement method with pre-measurement, comprising:

[0052] Applying an initialization waveform to a reading cavity coupled to the quantum bit, wherein the initialization waveform is composed of a plurality of waveforms and includes at least a waveform with a negative amplitude and a waveform with a positive amplitude that are sequentially spliced;

[0053] The initialization waveform is again applied to the read cavity.

[0054] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0055] The present invention provides a method for initializing a quantum bit reading cavity. The first step is to obtain an initialization waveform, which is composed of multiple waveforms and includes at least a waveform with a negative amplitude and a waveform with a positive amplitude, which are sequentially spliced together. The second step is to apply the initialization waveform to a reading cavity to complete the initialization of the reading cavity. The waveform with a negative amplitude destructively interferes with the existing electromagnetic field in the reading cavity, causing the standing wave in the reading cavity to decay and photons to radiate outward from the output end of the reading cavity. The initialization waveform can thus quickly empty the reading cavity of photons, shortening the time required to initialize the reading cavity compared to spontaneous photon emission. Pre-measurement using the initialization waveform can avoid the influence of the AC stack effect, while also eliminating the influence of system thermal excitation on experimental results, thereby improving the accuracy of quantum operations.

[0056] The quantum bit initialization device, readable storage medium, quantum computer and single-shot reading measurement method with pre-measurement proposed in the present invention belong to the same inventive concept as the quantum bit reading cavity initialization method provided in the present invention, and therefore have the same beneficial effects, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0058] Figure 1 1 is a flow chart of a method for initializing a quantum bit reading cavity according to an embodiment of the present invention;

[0059] Figure 2 FIG. 4 is a schematic diagram of the initialization waveform in an embodiment of the present invention. DETAILED DESCRIPTION

[0060] The following describes specific embodiments of the present invention in more detail with reference to schematic diagrams. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are greatly simplified and not to exact scale, and are intended solely to facilitate and clearly illustrate the embodiments of the present invention.

[0061] In the description of the present invention, it should be understood that the terms "center", "up", "down", "left", "right", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are 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 direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0062] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0063] An embodiment of the present invention provides a method for initializing a quantum bit reading cavity, see Figure 1 , Figure 1 This is a schematic diagram of a process for initializing the quantum bit reading cavity provided in this embodiment. The initialization method includes:

[0064] S1: Acquire an initialization waveform, where the initialization waveform is composed of a plurality of waveforms and at least includes a waveform with a negative amplitude and a waveform with a positive amplitude that are sequentially spliced together;

[0065] The reading cavity is coupled to a quantum bit, and the reading cavity can read the quantum state of the quantum bit into the reading cavity in a non-destructive manner. In addition, the reading cavity is also coupled to a reading bus, and a reading signal is applied to the reading cavity through the reading bus to read the quantum state information obtained in the reading cavity, thereby realizing the reading of the quantum state of the quantum bit.

[0066] As described in the background art, the process of applying the read signal to the read cavity will fill the read cavity with a large number of photons. After completing a read operation, the quantum bit needs to completely dissipate the photons in the read cavity before performing the next read operation, and the time spent waiting for the photons to spontaneously radiate is relatively long. In addition, in the process of performing a quantum bit operation, in order to eliminate the influence of thermal excitation of the system, a pre-measurement will be performed before the quantum bit operation is performed. However, the pre-measurement process will also fill the read cavity with a large number of photons, and the quantum bit after the pre-measurement cannot be used directly. The present invention uses the waveform with a negative amplitude in the initialization waveform to quickly empty the photons in the read cavity. The initialization waveform can reduce the number of photons in the read cavity.

[0067] S2: applying the initialization waveform to a reading cavity to initialize the reading cavity.

[0068] The method for initializing a quantum bit reading cavity provided by the present invention utilizes an initialization waveform to reduce the number of photons in the reading cavity. The initialization waveform is applied to the reading cavity to quickly empty the photons in the reading cavity, thereby initializing the reading cavity. Compared with spontaneous photon radiation, the time required to initialize the reading cavity is shortened. Pre-measurement using the initialization waveform can also avoid the influence of the AC stack effect, while eliminating the influence of system thermal excitation on experimental results, thereby improving the accuracy of quantum operations.

[0069] The initialization waveform includes a first waveform, a second waveform, and a third waveform spliced in sequence in time, wherein the second waveform has a negative amplitude, the third waveform has a positive amplitude, the time length of the first waveform is T1, and the amplitude is the first amplitude, the time length of the second waveform is T2, and the amplitude is the second amplitude, the time length of the third waveform is T3, and the amplitude is the third amplitude, and the first waveform, the second waveform, and the third waveform spliced in time sequence are used to reduce the number of photons in the reading cavity.

[0070] The first waveform can be obtained by:

[0071] Set the value of T1; the value of T1 can be set based on experience;

[0072] performing a single-shot read measurement without pre-measurement on a qubit coupled to the read cavity to obtain an amplitude of a read pulse of the qubit; the read pulse being a read signal applied to the read cavity during a read process;

[0073] The single-shot read measurement process is described below. A read signal is input and reaches the quantum chip. This signal does not directly affect the qubit, but rather interacts with the read cavity through scattering, changing the signal's amplitude and phase. By demodulating the signal returned from the quantum chip, the phase and amplitude changes of the read signal are analyzed, and the quantum state of the qubit is determined based on these changes. Typically, the read signal is a rectangular wave applied to the read cavity.

[0074] In a single-shot reading measurement without pre-measurement, only a rectangular wave is used as a reading signal and applied to the reading cavity; in addition, the duration of the rectangular wave can be set to the value of T1.

[0075] Here, a single-shot reading measurement with pre-measurement is described. Compared with the single-shot reading measurement without pre-measurement, it is necessary to add a same rectangular wave before the rectangular wave and apply it to the reading cavity.

[0076] determining the first amplitude based on the amplitude of the read pulse;

[0077] The first waveform is determined based on the T1 and the first amplitude.

[0078] The first waveform in the initialization waveform is determined through the above operation.

[0079] The second waveform and the third waveform are obtained by:

[0080] Setting the values of T2 and T3; the values of T2 and T3 can be preset based on experience; in addition, both T2 and T3 can be set to the inverse of the dissipation rate of the reading cavity;

[0081] Adjusting the values of the second amplitude and the third amplitude, and obtaining the residual photon number in the reading cavity, so that the residual photon number meets a preset requirement; in addition, to facilitate determining the amplitudes of the second amplitude and the third amplitude, the second waveform and the third waveform can be set to have equal amplitudes and opposite directions;

[0082] The second waveform and the third waveform are determined based on the values of T2, T3, the second amplitude, and the third amplitude.

[0083] The second waveform and the third waveform in the initialization waveform can be determined by the above operation, see Figure 2 , Figure 2 is a schematic diagram of the initialization waveform.

[0084] Specifically, adjusting the values of the second amplitude and the third amplitude, and obtaining the number of residual photons in the reading cavity so that the number of residual photons meets a preset requirement, includes:

[0085] Performing a single-shot read measurement without pre-measurement on a quantum bit coupled to the read cavity, and obtaining a fidelity of the single-shot read measurement result without pre-measurement as a first fidelity;

[0086] Setting the second amplitude and the third amplitude. The second amplitude and the third amplitude can be set in advance based on experience. In addition, since the first waveform has been determined based on the read pulse in the single-shot read measurement without pre-measurement, the initialization waveform to be adjusted is obtained. In this case, only the second amplitude and the third amplitude need to be adjusted.

[0087] Applying the initialization waveform to the reading cavity, performing reading within the existence time of the first amplitude, and obtaining the fidelity of the reading result as a second fidelity;

[0088] Since a Ramsey experiment needs to be performed on the qubit in subsequent operations, it is necessary to calibrate the delay of the bit state control signal line coupled to the qubit and the read pulse signal line coupled to the read cavity;

[0089] Performing a Ramsey experiment on the quantum bit to obtain the number of residual photons in the reading cavity;

[0090] Specifically, obtaining the number of residual photons in the reading cavity includes:

[0091] Obtaining the dissipation rate of the reading cavity; wherein obtaining the dissipation rate of the reading cavity comprises: applying a reading pulse to the reading cavity; applying an excitation signal to the quantum bit; obtaining the relationship between the bit frequency of the quantum bit and time; and obtaining the dissipation rate of the reading cavity based on the relationship between the bit frequency and time.

[0092] Obtaining the relaxation time of the quantum bit; specifically, obtaining the relaxation time of the quantum bit can be obtained by using a Ramsey experiment or a spin-echo experiment. Since obtaining the relaxation time of the quantum bit by using the Ramsey experiment or the spin-echo experiment is a conventional technical means that can be used by those skilled in the art, it will not be described here.

[0093] The results of the Ramsey experiment were used to fit the formula:

[0094]

[0095] Wherein, Γ2 is the inverse of the relaxation time, Δ is the Ramsey detuning, χ is the dispersion shift, κ is the dissipation rate, and n0 is the number of residual photons.

[0096] The residual photon number is obtained according to the fitting result.

[0097] Determine whether the residual photon number and the difference between the first fidelity and the second fidelity meet preset conditions; specifically, the preset conditions include: the residual photon number is less than 0.01; the difference between the first fidelity and the second fidelity is less than 1.5%.

[0098] If so, the magnitude of the second amplitude and the magnitude of the third amplitude meet the requirements;

[0099] If not, the second amplitude and the third amplitude are updated, and the process returns to applying the initialization waveform to the reading cavity, performing reading within the first amplitude existence time, and obtaining a second fidelity for the reading result.

[0100] The second waveform and the third waveform may be determined through the above specific operations.

[0101] Furthermore, the initialization waveform can be determined.

[0102] In summary, the present invention provides a method for initializing a quantum bit reading cavity, comprising: obtaining an initialization waveform, wherein the initialization waveform is composed of a plurality of waveforms and includes at least a waveform with a negative amplitude and a waveform with a positive amplitude spliced in sequence; and applying the initialization waveform to a reading cavity to initialize the reading cavity. The technical solution of the present invention can utilize the initialization waveform to quickly fill and empty the reading cavity with photons, thereby shortening the time required to initialize the reading cavity compared to spontaneous photon emission. Pre-measurement using the initialization waveform can avoid the influence of the ACstack effect, while eliminating the influence of system thermal excitation on experimental results, thereby improving the accuracy of quantum operations.

[0103] Based on the same inventive concept, the present invention provides an initialization device for a quantum bit reading cavity, comprising:

[0104] An initialization waveform acquisition module is used to acquire an initialization waveform, wherein the initialization waveform is composed of a plurality of waveforms and at least includes a waveform with a negative amplitude and a waveform with a positive amplitude spliced in sequence;

[0105] The initialization waveform applying module is used to apply the initialization waveform to a reading cavity to complete the initialization of the reading cavity.

[0106] Based on the same inventive concept, the present invention also provides a readable storage medium having a computer program stored thereon, which, when executed, can implement the initialization method of the quantum bit reading cavity provided by the present invention.

[0107] Specifically, in this embodiment, the above-mentioned storage medium may include but is not limited to: a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and other media that can store computer programs.

[0108] Based on the same inventive concept, the present invention further provides a quantum computer, which includes the initialization device for the quantum bit reading cavity provided by the present invention.

[0109] The quantum bit initialization device, readable storage medium, and quantum computer proposed in the present invention belong to the same inventive concept as the quantum bit reading cavity initialization method provided in the present invention, and therefore have the same beneficial effects, which will not be described in detail here.

[0110] The present invention also provides a single-shot reading measurement method with pre-measurement, comprising:

[0111] Applying an initialization waveform to a reading cavity coupled to the quantum bit, wherein the initialization waveform is composed of a plurality of waveforms and includes at least a waveform with a negative amplitude and a waveform with a positive amplitude that are sequentially spliced;

[0112] A rectangular wave is applied to the reading cavity. It should be noted that the initialization waveform can also be applied to the reading cavity again.

[0113] The single-shot reading measurement method with pre-measurement provided by the present invention utilizes the initialization waveform to quickly empty the number of photons in the reading cavity, thereby avoiding the influence of the AC stack effect on the quantum bit.

[0114] 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. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A method for initializing a quantum bit reading cavity, characterized in that: include: Obtaining an initialization waveform, the initialization waveform comprising a first waveform, a second waveform, and a third waveform spliced in sequence in time; wherein the amplitude of the first waveform is a first amplitude, the first amplitude being determined based on an amplitude of a read pulse of the qubit obtained by performing a single-shot read measurement without pre-measurement on the qubit coupled to the read cavity; the second amplitude of the second waveform is a negative value, and the third amplitude of the third waveform is a positive value, and the second and third amplitudes are determined based on whether a residual photon number in the read cavity meets a preset requirement; The initialization waveform is applied to a reading cavity to initialize the reading cavity.

2. The method for initializing a quantum bit reading cavity according to claim 1, wherein: The time length of the first waveform is T1, the time length of the second waveform is T2, and the time length of the third waveform is T3. The first waveform, the second waveform, and the third waveform spliced in time sequence are used to reduce the number of photons in the reading cavity.

3. The method for initializing a quantum bit reading cavity according to claim 2, wherein: The first waveform is obtained by: Set the value of T1; performing a single-shot read measurement without pre-measurement on a qubit coupled to the read cavity to obtain an amplitude of a read pulse of the qubit; determining the first amplitude based on the amplitude of the read pulse; The first waveform is determined based on the T1 and the first amplitude.

4. The method for initializing a quantum bit reading cavity according to claim 3, wherein: The second waveform and the third waveform are obtained in the following manner: Set the values of T2 and T3; Adjusting the values of the second amplitude and the third amplitude, and obtaining the number of residual photons in the reading cavity, so that the number of residual photons meets a preset requirement; The second waveform and the third waveform are determined based on the values of T2, T3, the second amplitude, and the third amplitude.

5. The method for initializing a quantum bit reading cavity according to claim 4, wherein: The adjusting the values of the second amplitude and the third amplitude, and obtaining the number of residual photons in the reading cavity so that the number of residual photons meets a preset requirement, includes: performing a single-shot read measurement without pre-measurement on a quantum bit coupled to the read cavity, and obtaining a fidelity of a single-shot read measurement result without pre-measurement as a first fidelity; Setting the amplitudes of the second amplitude and the third amplitude, applying the initialization waveform to the reading cavity, performing reading within the existence time of the first amplitude, and obtaining the fidelity of the reading result as the second fidelity; Performing a Ramsey experiment on the quantum bit to obtain the number of residual photons in the reading cavity; Determining whether the residual photon number and the difference between the first fidelity and the second fidelity meet a preset condition; if so, the amplitude of the second amplitude and the amplitude of the third amplitude meet the requirement; If not, the second amplitude and the third amplitude are updated, and the process returns to applying the initialization waveform to the reading cavity, performing reading within the first amplitude existence time, and obtaining a second fidelity for the reading result.

6. The method for initializing a quantum bit reading cavity according to claim 5, wherein: The preset conditions include: The residual photon number is less than 0.01; A difference between the first fidelity and the second fidelity is less than 1.5%.

7. The method for initializing a quantum bit reading cavity according to claim 5, wherein: Before performing the Ramsey experiment on the quantum bit, the method further includes: Calibrate the delay of the bit state control signal line coupled to the quantum bit and the read pulse signal line coupled to the read cavity.

8. The method for initializing a quantum bit reading cavity according to claim 5, wherein: The obtaining of the number of residual photons in the reading cavity comprises: obtaining a dissipation rate of the reading cavity; Obtaining a relaxation time of the quantum bit; The results of the Ramsey experiment were used to fit the formula: in Wherein, Γ2 is the inverse of the relaxation time, Δ is the Ramsey detuning, χ is the dispersion shift, κ is the dissipation rate, and n0 is the number of residual photons; The residual photon number is obtained according to the fitting result.

9. The method for initializing a quantum bit reading cavity according to claim 8, wherein: The obtaining of the dissipation rate of the reading cavity includes: applying a read pulse to the read cavity; applying an excitation signal to the quantum bit; Obtaining a relationship between a bit frequency of the quantum bit and time; The dissipation rate of the reading cavity is obtained based on the relationship between the bit frequency and time.

10. A device for initializing a quantum bit reading cavity, characterized in that: include: an initialization waveform acquisition module, configured to acquire an initialization waveform, the initialization waveform comprising a first waveform, a second waveform, and a third waveform sequentially spliced in time sequence; wherein the amplitude of the first waveform is a first amplitude, determined based on the amplitude of a read pulse of the qubit obtained by performing a single-shot read measurement without pre-measurement on the qubit coupled to the read cavity; the second amplitude of the second waveform is a negative value, and the third amplitude of the third waveform is a positive value, and the second and third amplitudes are determined based on whether the number of residual photons in the read cavity meets a preset requirement; The initialization waveform applying module is used to apply the initialization waveform to a reading cavity to complete the initialization of the reading cavity.

11. A readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed, the method for initializing the quantum bit reading cavity according to any one of claims 1 to 9 can be implemented.

12. A quantum computer, characterized in that: An initialization device comprising the quantum bit reading cavity as claimed in claim 10.

13. A single-shot reading measurement method with pre-measurement, characterized in that: include: Applying an initialization waveform to a read cavity coupled to a qubit, the initialization waveform comprising a first waveform, a second waveform, and a third waveform sequentially spliced in a time sequence; wherein the amplitude of the first waveform is a first amplitude, which is determined based on the amplitude of a read pulse of the qubit obtained by performing a single-shot read measurement without pre-measurement on the qubit coupled to the read cavity; the second amplitude of the second waveform is a negative value, and the third amplitude of the third waveform is a positive value, and the second and third amplitudes are determined based on whether the number of residual photons in the read cavity meets a preset requirement; A rectangular wave is applied to the reading cavity.

14. A single-shot reading measurement method with pre-measurement, characterized in that: include: Applying an initialization waveform to a read cavity coupled to a qubit, the initialization waveform comprising a first waveform, a second waveform, and a third waveform sequentially spliced in a time sequence; wherein the amplitude of the first waveform is a first amplitude, which is determined based on the amplitude of a read pulse of the qubit obtained by performing a single-shot read measurement without pre-measurement on the qubit coupled to the read cavity; the second amplitude of the second waveform is a negative value, and the third amplitude of the third waveform is a positive value, and the second and third amplitudes are determined based on whether the number of residual photons in the read cavity meets a preset requirement; The initialization waveform is again applied to the read cavity.

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