Quantum bit processing methods, computer-readable storage media, and computer devices

Abstract

This invention discloses a method for processing qubits, a computer-readable storage medium, and a computer device. The method relates to the field of quantum technology and includes: obtaining the values ​​of dephase factors corresponding to multiple first predetermined evolution times after the qubit evolves from a predetermined initial state at multiple predetermined evolution times; and determining the decoherence time of the qubit based on the multiple first predetermined evolution times and the values ​​of the dephase factors corresponding to the multiple first predetermined evolution times. This invention solves the technical problem of low efficiency in measuring the performance of qubits in related technologies.

Description

Technical Field

[0001] This invention relates to the field of quantum technology, and more specifically, to a method for processing qubits, a computer-readable storage medium, and a computer device. Background Technology

[0002] Measuring the decoherence time of qubits is fundamental to studying decoherence mechanisms. Spectral measurements of qubits also aid in decoherence research and can deduce relevant chip parameters, making it an essential step in optimizing micro / nano fabrication processes. In related technologies, Ramsey measurements are typically used to calibrate the decoherence time, employing long-wave excitation for frequency sweep measurements. However, these measurements require numerous data points and are time-consuming, hindering rapid system calibration and decoherence studies.

[0003] Therefore, in related technologies, there is a problem of low efficiency when measuring the performance of qubits.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] The present invention provides a quantum bit processing method, a computer-readable storage medium, and a computer device to at least solve the technical problem of low efficiency in measuring the performance of quantum bits in related technologies.

[0006] According to one aspect of the present invention, a quantum bit processing method is provided, comprising: obtaining the values ​​of dephase factors corresponding to the plurality of first predetermined evolution durations after the quantum bit evolves based on a predetermined initial state at a plurality of first predetermined evolution durations; and determining the decoherence time of the quantum bit based on the plurality of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations.

[0007] Optionally, obtaining the dephase factor values ​​corresponding to the multiple first predetermined evolution durations after the qubit evolves based on a predetermined initial state for each of the multiple first predetermined evolution durations includes: for any one of the multiple first predetermined evolution durations, after the qubit evolves based on the predetermined initial state for any one of the first predetermined evolution durations, applying multiple first magnetic flux pulses to the qubit for projection measurement to obtain first measurement results corresponding to the multiple first magnetic flux pulses; obtaining the dephase factor value corresponding to any one of the first predetermined evolution durations based on the first measurement results corresponding to the multiple first magnetic flux pulses; and obtaining the dephase factor values ​​corresponding to the multiple first predetermined evolution durations by using the method of obtaining the dephase factor values ​​corresponding to any one of the first predetermined evolution durations.

[0008] Optionally, the plurality of first magnetic flux pulses are three, and the phases of the projection measurements corresponding to the three first magnetic flux pulses are sequentially spaced 120 degrees apart.

[0009] Optionally, before obtaining the values ​​of the dephase factor corresponding to the multiple first predetermined evolution durations after the qubit evolves based on a predetermined initial state at multiple predetermined evolution durations, the method includes: determining a fixed evolution duration and a second magnetic flux pulse; determining multiple third magnetic flux pulses that include the second magnetic flux pulse within a predetermined range near the second magnetic flux pulse; after the qubit evolves based on the predetermined initial state at the fixed evolution duration, applying the multiple third magnetic flux pulses to the qubit for projection measurement to obtain candidate values ​​of the dephase factor corresponding to the multiple third magnetic flux pulses; selecting the third magnetic flux pulse with the largest candidate value of the dephase factor among the multiple third magnetic flux pulses as the target magnetic flux pulse; fixing the qubit under the target magnetic flux pulse, and evolving it based on the predetermined initial state at the multiple first predetermined evolution durations.

[0010] Optionally, determining the decoherence time of the qubit based on the plurality of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations includes: obtaining a first relationship curve between the dephase factors and the durations based on the plurality of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations; and determining the decoherence time of the qubit based on the first relationship curve.

[0011] Optionally, obtaining the first relationship curve between the dephase factor and the duration based on the plurality of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations includes: determining the number of the plurality of first predetermined evolution durations and a first fitting function; and obtaining the first relationship curve between the dephase factor and the duration based on the number of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the number of first predetermined evolution durations, using the first fitting function.

[0012] Optionally, determining the decoherence time of the qubit based on the first relationship curve includes: determining a target value for the dephase factor; and determining the duration on the first relationship curve corresponding to the target value as the decoherence time of the qubit.

[0013] Optionally, after determining the decoherence time of the qubit based on the plurality of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations, the method further includes: obtaining the values ​​of the decoherence times obtained by the qubit evolving under a plurality of fourth magnetic flux pulses; and obtaining a second relationship curve between the decoherence time and the magnetic flux pulse based on the values ​​of the decoherence times corresponding to the plurality of fourth magnetic flux pulses.

[0014] Optionally, the method further includes: obtaining the initial frequencies of the qubit under multiple fifth magnetic flux pulses; obtaining the phase change rate of the qubit under the application of the multiple fifth magnetic flux pulses; obtaining the frequency values ​​corresponding to the multiple fifth magnetic flux pulses based on the initial frequencies and phase change rates of the multiple fifth magnetic flux pulses; and obtaining a third relationship curve between the frequency of the qubit and the magnetic flux pulses based on the multiple fifth magnetic flux pulses and the frequency values ​​of the multiple fifth magnetic flux pulses.

[0015] Optionally, obtaining the phase change rate of the qubit under the application of the plurality of fifth magnetic flux pulses includes: for any fifth magnetic flux pulse among the plurality of fifth magnetic flux pulses, obtaining the phase value of the qubit after evolving for a plurality of second predetermined evolution durations under the application of the fifth magnetic flux pulse; determining the phase change rate of the qubit under the application of the fifth magnetic flux pulse based on the plurality of second predetermined evolution durations and the phase values ​​corresponding to the plurality of second predetermined evolution durations; and obtaining the phase change rate of the qubit under the application of the plurality of fifth magnetic flux pulses by using the method of obtaining the phase change rate of the application of the fifth magnetic flux pulse.

[0016] Optionally, obtaining the phase value of the qubit after evolving through multiple second predetermined evolution durations under any fifth magnetic flux pulse includes: determining a sixth magnetic flux pulse corresponding to any fifth magnetic flux pulse for any second predetermined evolution duration among the multiple second predetermined evolution durations, wherein the sixth magnetic flux pulse has the same amplitude as any fifth magnetic flux pulse, but the corresponding projected phase is different; after the qubit evolves based on the predetermined initial state for any second predetermined evolution duration, applying the any fifth magnetic flux pulse and the sixth magnetic flux pulse to the qubit for projection measurement to obtain a second measurement result of the any fifth magnetic flux pulse and a third measurement result corresponding to the sixth magnetic flux pulse; obtaining the phase value corresponding to any second predetermined evolution duration based on the second measurement result of the any fifth magnetic flux pulse and the third measurement result corresponding to the sixth magnetic flux pulse; and obtaining the phase value of the qubit after evolving through multiple second predetermined evolution durations under any fifth magnetic flux pulse by using the method of obtaining the phase value corresponding to any second predetermined evolution duration.

[0017] Optionally, determining the phase change rate of the qubit in any fifth magnetic flux pulse based on the plurality of second predetermined evolution durations and the phase values ​​corresponding to the plurality of second predetermined evolution durations includes: selecting two target second predetermined evolution durations from the plurality of second predetermined evolution durations, and determining the duration difference between the two target second predetermined evolution durations; determining the phase difference between the phase values ​​corresponding to the two target second predetermined evolution durations; and determining the phase change rate of the qubit in any fifth magnetic flux pulse based on the phase difference and the duration difference.

[0018] Optionally, the qubit is a Fluxonium qubit.

[0019] According to another aspect of the present invention, a qubit processing method is provided, comprising: displaying a qubit selection control on an interactive interface; displaying a target qubit on the interactive interface in response to an operation on the qubit selection control; receiving a decoherence time request for the target qubit; determining a decoherence time for the target qubit in response to the decoherence time request, wherein the decoherence time is obtained based on a plurality of first predetermined evolution durations and the values ​​of dephase factors corresponding to the plurality of first predetermined evolution durations, the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations being obtained after the target qubit evolves based on a predetermined initial state at the plurality of first predetermined evolution durations; and displaying the decoherence time on the interactive interface.

[0020] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform the quantum bit processing method described in any of the preceding claims.

[0021] According to another aspect of the present invention, a computer device is provided, comprising: a memory and a processor, the memory storing a computer program; the processor being configured to execute the computer program stored in the memory, wherein the computer program, when executed, causes the processor to perform the quantum bit processing method described in any of the preceding claims.

[0022] According to one aspect of the present invention, a quantum bit processing method is provided, comprising: obtaining frequency values ​​corresponding to the plurality of magnetic flux pulses obtained by applying the quantum bit to a predetermined initial state; and determining the relationship between the frequency of the quantum bit and the magnetic flux pulses based on the plurality of magnetic flux pulses and the frequency values ​​corresponding to the plurality of magnetic flux pulses.

[0023] Optionally, obtaining the frequency value corresponding to the plurality of magnetic flux pulses obtained by the qubit after applying the plurality of magnetic flux pulses based on a predetermined initial state includes: obtaining the initial frequency of the qubit under any one of the plurality of magnetic flux pulses; obtaining the phase change rate of the qubit under the application of the any one magnetic flux pulse; obtaining the frequency value corresponding to the any one magnetic flux pulse based on the initial frequency and the phase change rate; and obtaining the frequency value corresponding to the plurality of magnetic flux pulses obtained by the method of obtaining the frequency value corresponding to the any one magnetic flux pulse.

[0024] Optionally, obtaining the phase change rate of the qubit under the application of any magnetic flux pulse includes: obtaining the phase value of the qubit after evolving for a plurality of predetermined evolution times under the application of any magnetic flux pulse; and determining the phase change rate of the qubit under the application of any magnetic flux pulse based on the plurality of predetermined evolution times and the phase values ​​corresponding to the plurality of predetermined evolution times.

[0025] Optionally, obtaining the phase value of the qubit after evolving for multiple predetermined evolution durations under any magnetic flux pulse includes: for any predetermined evolution duration among the multiple predetermined evolution durations, determining other magnetic flux pulses corresponding to the any magnetic flux pulse, wherein the other magnetic flux pulses have the same amplitude as the any magnetic flux pulse, but different phases for projection measurement; after the qubit evolves for any predetermined evolution duration based on the predetermined initial state, applying the any magnetic flux pulse and the other magnetic flux pulses to the qubit for projection measurement to obtain the measurement result of the any magnetic flux pulse and the measurement result corresponding to the other magnetic flux pulses; obtaining the phase value corresponding to the any predetermined evolution duration based on the measurement result of the any magnetic flux pulse and the measurement result corresponding to the other magnetic flux pulses; and obtaining the phase value of the qubit after evolving for multiple predetermined evolution durations under any magnetic flux pulse by using the method of obtaining the phase value corresponding to the any predetermined evolution duration.

[0026] Optionally, determining the phase change rate of the qubit under any magnetic flux pulse based on the plurality of predetermined evolution durations and the phase values ​​corresponding to the plurality of predetermined evolution durations includes: selecting two target predetermined evolution durations from the plurality of predetermined evolution durations, and determining the duration difference between the two target predetermined evolution durations; determining the phase difference between the phase values ​​corresponding to the two target predetermined evolution durations; and determining the phase change rate of the qubit under any magnetic flux pulse based on the phase difference and the duration difference.

[0027] In this embodiment of the invention, the decoherence time of the qubit is obtained by acquiring the dephase factors corresponding to multiple evolution durations after the qubit has evolved for multiple evolution durations. Based on the multiple evolution durations and the dephase factors corresponding to the multiple evolution durations, the decoherence time of the qubit is obtained. By obtaining the decoherence time of the qubit using multiple evolution durations and the dephase factors corresponding to the multiple evolution durations, the goal of obtaining the decoherence time of the qubit with a small amount of measurement data is achieved. This realizes the technical effect of obtaining the qubit performance quickly and efficiently, and solves the technical problem of low efficiency in measuring the performance of qubits in related technologies. Attached Figure Description

[0028] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0029] Figure 1A hardware structure block diagram of a computer terminal for implementing a quantum bit processing method is shown.

[0030] Figure 2 This is a flowchart of a quantum bit processing method according to Embodiment 1 of the present invention;

[0031] Figure 3 This is a flowchart of a second method for processing qubits according to Embodiment 1 of the present invention;

[0032] Figure 4 This is a flowchart of a third method for processing qubits according to Embodiment 1 of the present invention;

[0033] Figure 5 This is a schematic diagram showing the evolution of projection results at three angles with three second magnetic flux pulses over an evolution time, according to an embodiment of the present invention.

[0034] Figure 6 This is a schematic diagram of determining the target working point according to an embodiment of the present invention;

[0035] Figure 7 This is a schematic diagram of obtaining decoherence time by fitting a curve according to an embodiment of the present invention;

[0036] Figure 8 This is a fitting curve of the frequency of a quantum bit as a function of magnetic flux pulses, provided according to an embodiment of the present invention.

[0037] Figure 9 This is a structural block diagram of a quantum bit processing device according to an embodiment of the present invention;

[0038] Figure 10 This is a structural block diagram of a second quantum bit processing device according to an embodiment of the present invention;

[0039] Figure 11 This is a structural block diagram of a second quantum bit processing device according to an embodiment of the present invention;

[0040] Figure 12 This is a structural block diagram of a computer terminal according to an embodiment of the present invention. Detailed Implementation

[0041] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0042] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0043] First, some nouns or terms that appear in the description of the embodiments of this application shall be interpreted as follows:

[0044] Quantum bit spectrum: The spectrum of a frequency-tunable quantum bit as the external modulation magnetic flux changes.

[0045] Dephase: The process by which a qubit loses its quantum coherence. The speed of dephase can be characterized by the dephase factor.

[0046] Projection measurement: Measuring by projecting qubits onto a specific direction.

[0047] Quantum decoherence: In quantum mechanics, the quantum coherence of an open quantum system gradually diminishes over time due to quantum entanglement with its environment. This effect is called quantum decoherence. Quantum decoherence is a consequence of quantum entanglement between the quantum system and its environment. Interference phenomena arising from quantum coherence disappear due to quantum decoherence. Quantum decoherence causes the system's quantum behavior to transition to classical behavior; this process is called the "quantum-to-classical transition."

[0048] The Ramsey interference experiment refers to the process of applying two π / 2 quantum logic gate operations to a qubit with a time interval of τ between the two operations, applying a readout pulse to the qubit after the second π / 2 quantum logic gate operation to obtain the excited state distribution P1(τ) of the qubit, and changing the time interval τ to obtain P1(τ).

[0049] Fluxonium, a type of superconducting quantum bit, is composed of Josephson junctions connected in parallel with inductors and capacitors. In this configuration, there is a large inductor (generally made using an array of a large number of Josephson junctions (100) or a high dynamic inductor material), a capacitor corresponding to the electrical energy EC, an inductor corresponding to the magnetic energy EL, and a Josephson energy EJ that are close to each other (within approximately one order of magnitude).

[0050] Example 1

[0051] According to an embodiment of the present invention, a method embodiment for processing qubits is also provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0052] The method embodiment provided in Embodiment 1 of this application can be executed in a mobile terminal, computer terminal or similar computing device. Figure 1 A hardware block diagram of a computer terminal (or mobile device) for implementing a quantum bit processing method is shown. Figure 1 As shown, the computer terminal 10 (or mobile device) may include one or more processors (shown as 102a, 102b, ..., 102n in the figure, and the processors may include, but are not limited to, processing devices such as microprocessors (MCUs) or programmable logic devices (FPGAs), a memory 104 for storing data, and a transmission device for communication functions. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of a BUS bus), a network interface, a power supply, and / or a camera. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the aforementioned electronic device. For example, computer terminal 10 may also include... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0053] It should be noted that the aforementioned one or more processors and / or other data processing circuits are generally referred to herein as "data processing circuits". These data processing circuits may be wholly or partially embodied in software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuits may be a single, independent processing module, or wholly or partially integrated into any other element within the computer terminal 10 (or mobile device). As involved in the embodiments of this application, the data processing circuit serves as a processor control mechanism (e.g., selection of a variable resistor termination path connected to an interface).

[0054] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the quantum bit processing method in this embodiment of the invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 104, thereby implementing the above-mentioned application vulnerability detection method. The memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor, and these remote memories can be connected to the computer terminal 10 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0055] The transmission device is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the communication provider of computer terminal 10. In one example, the transmission device includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0056] The display can be, for example, a touchscreen liquid crystal display (LCD) that allows the user to interact with the user interface of the computer terminal 10 (or mobile device).

[0057] It should be noted here that, in some optional embodiments, the above... Figure 1 The computer device (or mobile device) shown may include hardware elements (including circuitry), software elements (including computer code stored on a computer-readable medium), or a combination of both hardware and software elements. It should be noted that... Figure 1 This is only one instance of a specific particular instance and is intended to illustrate the types of components that may exist in the aforementioned computer device (or mobile device).

[0058] Under the aforementioned operating environment, this application provides the following: Figure 2 The method for processing qubits is shown. Figure 2 This is a flowchart of a quantum bit processing method according to Embodiment 1 of the present invention, as shown below. Figure 2 As shown, the process includes the following steps:

[0059] Step S202: Obtain the values ​​of the dephase factors corresponding to the multiple first predetermined evolution times after the qubit evolves based on a predetermined initial state under multiple first predetermined evolution times;

[0060] As an optional embodiment, the execution entity of the above-described quantum bit processing method can be a terminal or a server. The terminal can be of various types, such as a computer terminal, a mobile terminal, a virtual terminal, etc., but regardless of the type, it needs to possess sufficient computing power to meet the computational requirements. The server can also take many forms; for example, it can be a single computer device, a computer cluster comprising multiple computers, a local computing unit, or a remote cloud server, etc.

[0061] As an optional embodiment, the type of the above-mentioned qubit can be various, such as Fluxonium qubit, Transmon qubit, charge qubit, phase qubit, and other types of frequency-adjustable qubits. This application embodiment does not limit this.

[0062] As an optional embodiment, the aforementioned predetermined initial state can be prepared by applying a magnetic flux pulse to the qubit. It can be a random quantum state or a quantum state that meets certain requirements. Qubit decoherence refers to the loss of coherence of a qubit over time under the influence of the external environment. Therefore, a dephase factor can be used to describe the magnitude of the change in qubit coherence over time; that is, the dephase factor is positively correlated with the qubit coherence. This dephase factor decreases with increasing time. When the dephase factor is at its initial value, the qubit has the best coherence; when the dephase factor is ideally zero, the qubit is incoherent.

[0063] It should be noted that obtaining the aforementioned dephase factor requires measuring the qubit, and this measurement itself affects the qubit. The state of the qubit can then be deduced from the measurement results. Specifically, the measurement of the qubit can be performed based on a predetermined coordinate system. The measurement result can be the measurement result of the component of the qubit projected onto a certain coordinate axis in that coordinate system. The state of the entire qubit can be obtained based on the component results.

[0064] As an optional embodiment, the above evolution is the process by which a quantum state is influenced by its environment. The predetermined evolution duration mentioned above can be flexibly determined based on requirements. For example, the predetermined evolution duration can be several or tens of microseconds, etc. The predetermined evolution duration can be a duration comparable to the estimated decoherence time of the qubit. For example, if the estimated decoherence time of the qubit is tens of microseconds, the predetermined evolution duration can also be the corresponding tens of microseconds, etc.

[0065] As an optional embodiment, the above-mentioned acquisition of the dephase factor values ​​corresponding to the multiple first predetermined evolution durations after the qubit evolves based on the predetermined initial state for multiple predetermined evolution durations means that after the qubit evolves based on the predetermined initial state for one predetermined evolution duration, it can obtain the value of one dephase factor corresponding to that predetermined evolution duration. When the qubit evolves based on the predetermined initial state for different predetermined evolution durations, it obtains different dephase factor values.

[0066] As an optional embodiment, when obtaining the values ​​of the dephase factors corresponding to the multiple first predetermined evolution durations after the qubit evolves based on a predetermined initial state for each of the multiple first predetermined evolution durations, the following method can be used: For any one of the multiple first predetermined evolution durations, after the qubit evolves based on the predetermined initial state for any one of the first predetermined evolution durations, multiple first magnetic flux pulses are applied to the qubit for projection measurement to obtain the first measurement results corresponding to the multiple first magnetic flux pulses; based on the first measurement results corresponding to the multiple first magnetic flux pulses, the value of the dephase factor corresponding to any one first predetermined evolution duration is obtained; by using the method of obtaining the value of the dephase factor corresponding to any one first predetermined evolution duration, the value of the dephase factor corresponding to the multiple first predetermined evolution durations is obtained.

[0067] As an optional embodiment, when obtaining the value of the dephase factor corresponding to any first predetermined evolution time based on the first measurement results corresponding to multiple first magnetic flux pulses, it can be obtained based on the relationship between the measurement results and the dephase factor. For example, it can be determined by the functional relationship between the measurement results and the dephase factor. For instance, the dephase factor can be characterized as a function with the measurement results corresponding to multiple first magnetic flux pulses as variables (this function can be derived based on certain theories). When the first measurement results corresponding to multiple first magnetic flux pulses are obtained, the first measurement results corresponding to multiple first magnetic flux pulses can be substituted into the above function to obtain the value of the corresponding dephase factor.

[0068] It should be noted that the number of the aforementioned multiple first magnetic flux pulses is not limited; for example, it can be two or three. The phases of the projection measurements corresponding to the three first magnetic flux pulses are sequentially spaced at predetermined phase intervals, for example, 120 degrees. Therefore, the aforementioned multiple first magnetic flux pulses can be pulses with the same amplitude, but the phases of the projection measurements corresponding to the three first magnetic flux pulses are different. It should be pointed out that the magnetic flux pulse referred to as the first magnetic flux pulse can be understood as the commonly used magnetic flux bias. Furthermore, when using two magnetic flux pulses to obtain the dephase factor corresponding to the predetermined evolution time, some instability may occur due to the need for corresponding environmental constraints. Therefore, to avoid instability caused by the environment, a method of projecting measurements using three magnetic flux pulses can be chosen to determine the dephase factor corresponding to the predetermined evolution time.

[0069] As an optional embodiment, before obtaining the values ​​of the decoherence factors corresponding to the multiple first predetermined evolution times after the qubit evolves based on a predetermined initial state, the decoherence of the qubit varies depending on its operating state. To more comprehensively and efficiently represent the decoherence process and obtain the entire decoherence process, the qubit can be operated at a target operating point. Therefore, before evolving the qubit based on the predetermined initial state for the predetermined duration, the ideal operating state of the qubit can be determined first (i.e., the state corresponding to the target operating point, where the decoherence time of the qubit is longer and the controllable adjustment range is larger), and the qubit can be controlled to be at the target operating point, so that the qubit evolves at the target operating point.

[0070] As an optional embodiment, the target operating point of the qubit can be determined as follows: A fixed evolution duration and a second magnetic flux pulse are determined; multiple third magnetic flux pulses, including the second magnetic flux pulse, are determined within a predetermined range near the second magnetic flux pulse; after the qubit evolves based on a predetermined initial state for the fixed evolution duration, the multiple third magnetic flux pulses are applied to the qubit for projection measurement to obtain candidate values ​​of the dephase factor corresponding to the multiple third magnetic flux pulses; the third magnetic flux pulse with the largest candidate value of the dephase factor among the multiple third magnetic flux pulses is selected as the target magnetic flux pulse; the qubit is fixed under the target magnetic flux pulse, and evolves based on the predetermined initial state for multiple first predetermined evolution durations. Through the above processing, within a fixed evolution duration, using the second magnetic flux pulse as an initial magnetic flux pulse, the magnetic flux pulse with the largest value of the dephase factor near this initial magnetic flux pulse is searched as the target operating point of the qubit. It should be noted that the process of determining the dephase factor for a magnetic flux pulse is similar to the process described above. That is, the dephase factor corresponding to the magnetic flux pulse can be obtained by performing three measurements with the magnetic flux pulse (with different phases in the three measurements). Then, the qubit is controlled to undergo the aforementioned evolution for multiple predetermined evolution durations under the magnetic flux bias corresponding to the target operating point.

[0071] Step S204: Determine the decoherence time of the qubit based on multiple first predetermined evolution durations and the values ​​of dephase factors corresponding to the multiple first predetermined evolution durations.

[0072] As an optional embodiment, when determining the decoherence time of a qubit based on multiple first predetermined evolution durations and the values ​​of dephase factors corresponding to these durations, various methods can be employed. For example, a first relationship curve between the dephase factors and the duration can be obtained based on the multiple first predetermined evolution durations and the values ​​of the dephase factors corresponding to these durations; then, the decoherence time of the qubit can be determined based on this first relationship curve. It should be noted that when obtaining the first relationship curve between the dephase factors and the duration based on multiple first predetermined evolution durations and the values ​​of the dephase factors corresponding to these durations, the method for obtaining this first relationship curve can also be varied. For example, curve fitting can be used, or it can be obtained automatically using artificial intelligence (AI). No specific limitations are imposed here. When using curve fitting, a relationship curve corresponding to a certain type of fitting function can be obtained based on a certain amount of existing data. Alternatively, when using AI to automatically acquire data, it can be based on training a machine model with AI. This allows the trained model to output the evolutionary patterns of the received data, thus obtaining the aforementioned first relationship curve.

[0073] As an optional embodiment, a simple fitting method can be used in the above-mentioned curve fitting process, that is, fitting discrete points with a predetermined fitting function to obtain the fitting result. For example, based on multiple first predetermined evolution durations and the values ​​of the dephase factors corresponding to the multiple first predetermined evolution durations, the first relationship curve between the dephase factors and the duration can be obtained in the following way: determine the number of multiple first predetermined evolution durations and the first fitting function; based on the number of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the number of first predetermined evolution durations, use the first fitting function to obtain the first relationship curve between the dephase factors and the duration. Through the above processing, using a certain number of discrete first predetermined evolution durations and the corresponding values ​​of the dephase factors, and using the first fitting function, the relationship curve between the dephase factors and the duration is obtained. It should be noted that the above-mentioned first fitting function can be determined based on the empirical characteristics of the decoherence time. For example, an exponential function can be selected as the first fitting function, wherein the exponential function can be an exponentially decreasing form.

[0074] As an optional embodiment, when determining the decoherence time of a qubit based on the first relationship curve, a target value of the dephase factor is selected, and the duration corresponding to this target value on the first relationship curve is determined as the decoherence time of the qubit. For example, a target value of the dephase factor can be determined first; the duration corresponding to the target value on the first relationship curve is then determined as the decoherence time of the qubit. This target value can be determined based on a certain standard, such as the fitting function corresponding to the first relationship curve. For instance, in general, when the fitting function reaches a certain standard value, coherence is considered to have ended, meaning the qubit lacks coherence. Therefore, the dephase factor corresponding to this standard value is the aforementioned target value. For example, with the exponentially decreasing form of the above exponential function, the target value can be obtained based on 1 / e. For instance, the decoherence time of the qubit is the duration corresponding to the dephase factor reaching its maximum value on the first relationship curve.

[0075] Through the above steps, the dephase factor corresponding to multiple evolution durations of the qubit is obtained after multiple evolution durations. Based on the dephase factor corresponding to multiple evolution durations, a fitting curve between the dephase factor and the duration is obtained, and the decoherence time of the qubit is obtained based on the fitting network. By obtaining the decoherence time of the qubit through the fitting curve, the goal of obtaining the decoherence time of the qubit with a small amount of measurement data is achieved. This realizes the technical effect of obtaining the performance of the qubit quickly and efficiently, and solves the technical problem of low efficiency in measuring the performance of qubits in related technologies.

[0076] As an optional embodiment, as described above, different magnetic flux pulses affect the decoherence time of the qubit. Therefore, to obtain the influence of different magnetic flux pulses on the decoherence time, after determining the decoherence time of the qubit based on multiple first predetermined evolution durations and the values ​​of the dephase factors corresponding to the multiple first predetermined evolution durations, the decoherence time values ​​obtained by the qubit evolving under multiple fourth magnetic flux pulses can be obtained using the aforementioned method for obtaining the decoherence time. Based on the decoherence time values ​​corresponding to the multiple fourth magnetic flux pulses, a second relationship curve between the decoherence time and the magnetic flux pulse can be obtained. The fitting method can refer to the method used to obtain the first relationship curve between the dephase factor and the duration.

[0077] As an optional embodiment, the performance of a qubit can include not only decoherence time but also a spectrum based on tunable frequencies. To obtain the qubit's spectrum, the relationship curve between the qubit's frequency and magnetic flux pulses can be acquired when needed. For example, this can be achieved by: acquiring the initial frequencies of the qubit under multiple fifth magnetic flux pulses; acquiring the phase change rate of the qubit under multiple applied fifth magnetic flux pulses; obtaining the frequency values ​​corresponding to the multiple fifth magnetic flux pulses based on the initial frequencies and phase change rates; and acquiring a third relationship curve between the qubit's frequency and magnetic flux pulses based on the multiple fifth magnetic flux pulses and their corresponding frequency values. Through the above processing, by acquiring the frequency values ​​corresponding to the multiple fifth magnetic flux pulses and the multiple fifth magnetic flux pulses themselves, the relationship curve between the qubit's frequency and magnetic flux pulses is obtained, thus yielding the qubit's spectrum. In other words, by performing simple measurements on the qubit and fitting the measurement results, the qubit's spectrum is obtained. Compared to related technologies, this method of obtaining the qubit's spectrum is faster, simpler, and effectively reduces the time required for qubit performance testing.

[0078] As an optional embodiment, obtaining the phase change rate of a qubit under the application of multiple fifth magnetic flux pulses includes: for any fifth magnetic flux pulse, obtaining the phase value of the qubit after evolving for multiple second predetermined evolution durations under any fifth magnetic flux pulse; determining the phase change rate of the qubit under any fifth magnetic flux pulse based on the multiple second predetermined evolution durations and the phase values ​​corresponding to the multiple second predetermined evolution durations; and obtaining the phase change rate of the qubit under the application of multiple fifth magnetic flux pulses by using the method of obtaining the phase change rate of any fifth magnetic flux pulse. Using the above processing method, when obtaining the corresponding phase change rate for any fifth magnetic flux pulse, it is determined based on multiple second predetermined evolution durations and the phase values ​​corresponding to the multiple second predetermined evolution durations. A simple processing method is to determine the change in phase value under the change duration corresponding to the evolution duration, that is, the ratio of the phase difference to the evolution duration difference, which is the phase change rate corresponding to any fifth magnetic flux pulse.

[0079] It should be noted that when obtaining the phase value of a qubit after it has evolved through multiple second predetermined evolution times under any fifth magnetic flux pulse, the above-mentioned method of obtaining the dephase factor can be used, or the same measurement process can be used to obtain the phase value of the qubit under a certain fifth magnetic flux pulse while obtaining the dephase factor of the qubit under a certain fifth magnetic flux pulse. For example, the phase value of a qubit after evolving for multiple predetermined evolution periods under any fifth magnetic flux pulse can be obtained in the following way: For any second predetermined evolution period among the multiple predetermined evolution periods, a sixth magnetic flux pulse corresponding to any fifth magnetic flux pulse is determined, wherein the amplitude of the sixth magnetic flux pulse is the same as that of any fifth magnetic flux pulse, but the corresponding projected phase is different; after the qubit evolves for any second predetermined evolution period based on a predetermined initial state, the fifth and sixth magnetic flux pulses are applied to the qubit for projection measurement, respectively, to obtain a second measurement result of the fifth magnetic flux pulse and a third measurement result corresponding to the sixth magnetic flux pulse; based on the second measurement result of the fifth magnetic flux pulse and the third measurement result corresponding to the sixth magnetic flux pulse, the phase value corresponding to any second predetermined evolution period is obtained; by using the method of obtaining the phase value corresponding to any second predetermined evolution period, the phase value of the qubit after evolving for multiple predetermined evolution periods under any fifth magnetic flux pulse can be obtained. The difference between this method and the method for obtaining the dephase factor of a qubit lies only in the target parameter: one is the dephase factor, and the other is the phase value. When the dephase factor and the phase value are obtained using the same measurement process, any of the fifth and sixth magnetic flux pulses mentioned above correspond to the plurality of first magnetic flux pulses mentioned above.

[0080] As an optional embodiment, when determining the phase change rate of a qubit in any fifth magnetic flux pulse based on multiple second predetermined evolution durations and the phase values ​​corresponding to each of the multiple second predetermined evolution durations, the following method can be adopted: select two target second predetermined evolution durations from the multiple second predetermined evolution durations, and determine the duration difference between the two target second predetermined evolution durations; determine the phase difference between the phase values ​​corresponding to the two target second predetermined evolution durations; and determine the phase change rate of the qubit in any fifth magnetic flux pulse based on the phase difference and the duration difference. Specifically, when determining the phase change rate of the qubit in any fifth magnetic flux pulse based on the phase difference and the duration difference, a simpler method can be used: determining the ratio between the phase difference and the duration difference as the phase change rate. Optionally, the phase change rate can be obtained by linear fitting a set of measured phases and their corresponding evolution durations, where the slope of the fitted linear function corresponds to the phase change rate.

[0081] Figure 3 This is a flowchart of a second method for processing qubits according to Embodiment 1 of the present invention, as shown below. Figure 3 As shown, the process includes the following steps:

[0082] Step S302: Display the quantum bit selection control on the interactive interface;

[0083] Step S304: In response to the operation of the qubit selection control, the target qubit is displayed on the interactive interface;

[0084] Step S306: Receive a decoherence time request for the target qubit;

[0085] Step S308: In response to the decoherence time request, determine the decoherence time of the target qubit, wherein the decoherence time is obtained based on a plurality of first predetermined evolution durations and the values ​​of dephase factors corresponding to the plurality of first predetermined evolution durations, and the values ​​of dephase factors corresponding to the plurality of first predetermined evolution durations are obtained after the target qubit evolves based on a predetermined initial state under the plurality of first predetermined evolution durations respectively.

[0086] Step S310: Display the decoherence time on the interactive interface.

[0087] Through the above steps, by interactively operating on the interface, the dephase factors corresponding to multiple evolution durations of the qubit are obtained after multiple evolution durations. Based on these multiple evolution durations and the corresponding dephase factors, the decoherence time of the qubit is obtained, and the decoherence time is displayed on the interactive interface. This not only achieves the goal of obtaining the decoherence time of the qubit with a small amount of measurement data, thus realizing the technical effect of quickly and efficiently obtaining the performance of the qubit, but also solves the technical problem of low efficiency in measuring the performance of qubits in related technologies by displaying the decoherence time in an explicit and intuitive way.

[0088] Figure 4 This is a flowchart of a third method for processing qubits according to Embodiment 1 of the present invention, as shown below. Figure 4 As shown, the process includes the following steps:

[0089] Step S402: Obtain the frequency values ​​corresponding to the multiple magnetic flux pulses obtained by the qubit based on a predetermined initial state after applying multiple magnetic flux pulses;

[0090] Step S404: Based on multiple magnetic flux pulses and the frequency values ​​corresponding to the multiple magnetic flux pulses, determine the relationship between the frequency of the qubit and the magnetic flux pulses.

[0091] Through the above steps, the frequency values ​​corresponding to multiple magnetic flux pulses are obtained after applying multiple magnetic flux pulses based on a predetermined initial state of the qubit. Based on the frequency values ​​corresponding to multiple magnetic flux pulses, the relationship between the frequency of the qubit and the magnetic flux pulses is obtained, that is, the spectrum of the qubit. This not only achieves the goal of obtaining the spectrum of the qubit with a small amount of measurement data, but also realizes the technical effect of obtaining the performance parameters of the qubit (the spectrum of the qubit) quickly and efficiently. This solves the technical problem of low efficiency in measuring the performance of qubits in related technologies.

[0092] It should be noted that the method of directly determining the spectrum of a qubit based on measurement data described above can be performed simultaneously with the measurement process used to determine the decoherence time, and the obtained measurement data can be similar. Therefore, the process of obtaining the decoherence time and the spectrum of a qubit based on this measurement data can also be similar, the only difference being the type of parameter determined: one is the decoherence time, and the other is the spectrum. Therefore, the scheme for obtaining the spectrum of a qubit separately described below can be similar to the scheme used to obtain the spectrum when combining the decoherence time and the spectrum, or can be flexibly varied. Therefore, the specific process of obtaining the spectrum directly will not be elaborated on in detail for similar treatments.

[0093] Optionally, obtaining the frequency value of the qubit corresponding to the multiple magnetic flux pulses after applying multiple magnetic flux pulses based on a predetermined initial state includes: obtaining the initial frequency of the qubit under any magnetic flux pulse for any one of the multiple magnetic flux pulses; obtaining the phase change rate of the qubit under any magnetic flux pulse; obtaining the frequency value corresponding to any magnetic flux pulse based on the initial frequency and the phase change rate; and obtaining the frequency value corresponding to the multiple magnetic flux pulses after applying multiple magnetic flux pulses by using the method of obtaining the frequency value corresponding to any magnetic flux pulse.

[0094] Optionally, obtaining the phase change rate of the qubit under any magnetic flux pulse includes: obtaining the phase value of the qubit after evolving for multiple predetermined evolution times under any magnetic flux pulse; and determining the phase change rate of the qubit under any magnetic flux pulse based on the multiple predetermined evolution times and the phase values ​​corresponding to the multiple predetermined evolution times.

[0095] Optionally, obtaining the phase value of a qubit after evolving for multiple predetermined evolution durations under any magnetic flux pulse includes: for any predetermined evolution duration among the multiple predetermined evolution durations, determining other magnetic flux pulses corresponding to any magnetic flux pulse, wherein the other magnetic flux pulses have the same amplitude as any magnetic flux pulse, but different phases for projection measurement; after the qubit evolves for any predetermined evolution duration based on a predetermined initial state, applying the any magnetic flux pulse and other magnetic flux pulses to the qubit for projection measurement to obtain the measurement result of the any magnetic flux pulse and the measurement result corresponding to the other magnetic flux pulses; obtaining the phase value corresponding to any predetermined evolution duration based on the measurement result of the any magnetic flux pulse and the measurement result corresponding to the other magnetic flux pulses; and obtaining the phase value of the qubit after evolving for multiple predetermined evolution durations under any magnetic flux pulse by using the method of obtaining the phase value corresponding to any predetermined evolution duration.

[0096] Optionally, based on multiple predetermined evolution durations and the phase values ​​corresponding to each predetermined evolution duration, the phase change rate of the qubit under any magnetic flux pulse is determined, including: selecting two target predetermined evolution durations from the multiple predetermined evolution durations, and determining the duration difference between the two target predetermined evolution durations; determining the phase difference between the phase values ​​corresponding to the two target predetermined evolution durations; and determining the phase change rate of the qubit under any magnetic flux pulse based on the phase difference and the duration difference.

[0097] Based on the above embodiments and optional embodiments, an optional implementation method is provided.

[0098] The method provided in this invention has wide applications, including the study of decoherent correlation noise in Fluxonium bits, the calibration of the Fluxonium bit spectrum, and the calibration of micro / nano fabrication parameters for feedback.

[0099] An optional embodiment of the present invention can utilize multiple projection measurements of the qubit (e.g., three measurements spaced 120 degrees apart) to quickly estimate the decoherence information and accumulated dynamic phase of the initial qubit with the fewest possible data points. This approach can significantly reduce the experimental time for studying the dephase variation with external magnetic flux (by more than half compared to previous methods), while also quickly calibrating the qubit frequency as a function of external magnetic flux.

[0100] The optional implementation method is described below.

[0101] 1. The qubit is prepared in a superposition state using the first pi-half (pi / 2) pulse. After allowing it to evolve freely for a period of time, a second pi-half pulse is applied for projection measurement. This projection measurement needs to be performed three times, with the phase of the second pulse spaced 120 degrees apart in each of the three measurements. Figure 5 This is a schematic diagram illustrating the evolution of the three projection measurement results provided by the embodiment of the present invention with the second magnetic flux pulse over the evolution time, as shown below. Figure 5 As shown, on the left side of the figure, the phases (1, 2, 3) of the three projection measurements are spaced 120 degrees apart. After evolution over time, the projection measurements on the Z-axis can be seen from curve 4 in the figure. The right side of the figure shows the dephase factor and the dephase information derivation process. In the figure, P1, P2, and P2 represent the probabilities of the three measurements, respectively.

[0102] From the three measurement results, the corresponding decoherence factor a1 and the corresponding phase information varphi can be extracted. Using this information, the decoherence time and spectrum of the qubit can be measured quickly, and the two information can be combined to study the decoherence mechanism.

[0103] 2. By fixing a time delay of approximately 10–20 μs, and near an initial flux pulse (wherein the initial flux pulse can be a flux pulse considered closely related to the flux pulse corresponding to the target operating point, and this initial flux pulse can be obtained empirically or through preliminary calculations), the height (i.e., amplitude) of the flux pulse between two pi-half pulses can be continuously changed. The height of the flux pulse corresponding to the maximum a1 can then be measured. This amplitude value corresponds to the target operating point of the bit. Figure 6 This is a schematic diagram of determining the target working point according to an embodiment of the present invention, such as... Figure 6As shown in the figure, when an initial magnetic flux is given (which can be the horizontal coordinate of any point on the curve in the figure), the dephase factor corresponding to the magnetic flux pulse corresponding to that point and the points near that point is determined respectively. As can be seen from the figure, the point marked by the arrow is the location where the dephase factor is the maximum, that is, the horizontal coordinate corresponding to that point is the magnetic flux pulse corresponding to the target operating point of the quantum bit.

[0104] 3. By fixing the bit at the target operating point and continuously changing the delay point (i.e., corresponding to different evolution durations), the corresponding decoherence time can be obtained by fitting. Figure 7 This is a schematic diagram illustrating the decoherence time obtained by fitting a curve according to an embodiment of the present invention, as shown below. Figure 7 As shown, during the fitting process, multiple evolution durations and corresponding decoherence times (discrete points in the figure) are used. Based on a predetermined fitting function (an exponential function in the figure as an example), the relationship between the decoherence factor and time is fitted (i.e., the curve in the figure). Then, the target decoherence factor that satisfies the termination of decoherence is determined, and the duration corresponding to this target decoherence factor is the decoherence time of the qubit.

[0105] In addition, to obtain the law of quantum bit variation with magnetic flux, the above process of obtaining decoherence time can be repeated. By changing the magnetic flux pulse height in the above process, relevant data on decoherence time variation with magnetic flux can be obtained.

[0106] 4. When measuring the frequency of a qubit, an initial guess of the frequency under a certain magnetic flux pulse can be given (such as the initial frequency mentioned above). Then, the slope of the change in the bit's phase information (such as the phase change rate mentioned above) is measured using the above method. The sum of this slope and the initial guess is the actual frequency of the bit. Figure 8 This is a fitting curve of the frequency of a quantum bit as a function of magnetic flux pulses, provided according to an embodiment of the present invention, such as... Figure 8 As shown in the figure, the discrete points are the measured values, the curve is the fitted curve, and the fitted curve is the spectrum of the quantum bit.

[0107] It should be noted that similar functions can be achieved by two or more projection measurements in the embodiments of the present invention, but three projection measurements are a better solution that balances stability and measurement speed.

[0108] The optional embodiment of this invention proposes a three-angle projection measurement method for measuring the dynamic evolution of bits under a decoherence mechanism. This method can quickly extract decoherence and spectral information, and in practical tests, it has been found to have strong robustness. Furthermore, the number of data points required for calibrating decoherence time and frequency is significantly less than traditional methods, and because phase and decoherence information are determined through three consecutive points, the measurement results are less susceptible to external environmental influences.

[0109] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0110] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a computer-readable storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0111] Example 2

[0112] According to an embodiment of the present invention, an apparatus for implementing the above-described quantum bit processing method is also provided. Figure 9 This is a structural block diagram of a quantum bit processing device according to an embodiment of the present invention, such as... Figure 9 As shown, the device includes a first acquisition module 92 and a first determination module 94. The device will be described below.

[0113] The first acquisition module 92 is used to acquire the values ​​of the dephase factors corresponding to the multiple first predetermined evolution times obtained after the qubit evolves based on a predetermined initial state under multiple first predetermined evolution times; the first determination module 94 is connected to the first acquisition module 92 and is used to determine the decoherence time of the qubit based on the multiple first predetermined evolution times and the values ​​of the dephase factors corresponding to the multiple first predetermined evolution times.

[0114] It should be noted that the first acquisition module 92 and the first determination module 94 mentioned above correspond to steps S202 to S204 in Embodiment 1. The two modules and their corresponding steps implement the same instances and application scenarios, but are not limited to the content disclosed in Embodiment 1. It should also be noted that the above modules, as part of the device, can run in the computer terminal 10 provided in Embodiment 1.

[0115] According to an embodiment of the present invention, an apparatus for implementing the above-described second method for processing qubits is also provided. Figure 10 This is a structural block diagram of a quantum bit processing device two provided according to an embodiment of the present invention, as shown below. Figure 10 As shown, the device includes a display module 102, a receiving module 104, and a second determining module 106. The device will be described below.

[0116] Display module 102 displays a qubit selection control on the interactive interface; in response to the operation of the qubit selection control, it displays the target qubit on the interactive interface; receiving module 104, connected to the display module 102, is used to receive a decoherence time request for the target qubit; second determining module 106, connected to the receiving module 104, is used to determine the decoherence time of the target qubit in response to the decoherence time request, wherein the decoherence time is obtained based on a plurality of first predetermined evolution durations and the values ​​of dephase factors corresponding to the plurality of first predetermined evolution durations, and the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations are obtained after the target qubit evolves based on a predetermined initial state under the plurality of first predetermined evolution durations; display module 102 is also used to display the decoherence time on the interactive interface.

[0117] It should be noted that the display module 102, the receiving module 104, and the second determining module 106 correspond to steps S302 to S306 in Embodiment 1. The instances and application scenarios implemented by these modules and their corresponding steps are the same, but they are not limited to the content disclosed in Embodiment 1. It should also be noted that these modules, as part of the device, can run in the computer terminal 10 provided in Embodiment 1.

[0118] According to an embodiment of the present invention, an apparatus for implementing the above-described third method for processing qubits is also provided. Figure 11 This is a structural block diagram of a quantum bit processing device three provided according to an embodiment of the present invention, as shown below. Figure 11 As shown, the device includes a second acquisition module 112 and a third determination module 114. The device will be described below.

[0119] The second acquisition module 112 is used to acquire the frequency values ​​corresponding to the multiple magnetic flux pulses obtained by the quantum bit after applying multiple magnetic flux pulses based on a predetermined initial state; the third determination module 114 is connected to the second acquisition module 112 and is used to determine the relationship between the frequency of the quantum bit and the magnetic flux pulses based on the multiple magnetic flux pulses and the frequency values ​​corresponding to the multiple magnetic flux pulses.

[0120] It should be noted that the second acquisition module 112 and the third determination module 114 mentioned above correspond to steps S402 to S404 in Embodiment 1. The two modules and their corresponding steps implement the same instances and application scenarios, but are not limited to the content disclosed in Embodiment 1. It should also be noted that the above modules, as part of the device, can run in the computer terminal 10 provided in Embodiment 1.

[0121] Example 3

[0122] Embodiments of the present invention can provide a computer terminal, which can be any computer terminal device in a group of computer terminals. Optionally, in this embodiment, the computer terminal can also be replaced by a mobile terminal or other terminal device.

[0123] Optionally, in this embodiment, the computer terminal may be located in at least one of a plurality of network devices in a computer network.

[0124] In this embodiment, the computer terminal can execute the program code for the following steps in the quantum bit processing method of the application: obtaining the values ​​of the dephase factors corresponding to the multiple first predetermined evolution durations after the quantum bit evolves based on a predetermined initial state at multiple first predetermined evolution durations; obtaining a first relationship curve between the dephase factors and the duration based on the multiple first predetermined evolution durations and the values ​​of the dephase factors corresponding to the multiple first predetermined evolution durations; and determining the decoherence time of the quantum bit based on the first relationship curve.

[0125] Optionally, Figure 12 This is a structural block diagram of a computer terminal according to an embodiment of the present invention. Figure 12 As shown, the computer terminal may include one or more (only one is shown in the figure) processors 122, memory 124, etc.

[0126] The memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the quantum bit processing method and apparatus in this embodiment of the invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, thereby realizing the aforementioned quantum bit processing method. The memory may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to a computer terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0127] The processor can call the information and application stored in the memory through the transmission device to perform the following steps: obtain the values ​​of the dephase factors corresponding to the multiple first predetermined evolution times after the qubit evolves based on a predetermined initial state at multiple first predetermined evolution times; determine the decoherence time of the qubit based on the multiple first predetermined evolution times and the values ​​of the dephase factors corresponding to the multiple first predetermined evolution times.

[0128] Optionally, the processor may also execute program code for the following steps: obtaining the values ​​of dephase factors corresponding to the multiple first predetermined evolution durations after the qubit evolves based on a predetermined initial state for multiple first predetermined evolution durations, including: for any one of the multiple first predetermined evolution durations, after the qubit evolves based on the predetermined initial state for any one of the first predetermined evolution durations, applying multiple first magnetic flux pulses to the qubit for projection measurement to obtain first measurement results corresponding to the multiple first magnetic flux pulses; obtaining the value of the dephase factor corresponding to any one of the first predetermined evolution durations based on the first measurement results corresponding to the multiple first magnetic flux pulses; and obtaining the values ​​of the dephase factors corresponding to the multiple first predetermined evolution durations by using the method of obtaining the value of the dephase factor corresponding to any one of the first predetermined evolution durations.

[0129] Optionally, the processor may also execute program code with the following steps: multiple first magnetic flux pulses are three, and the phases of the projection measurements corresponding to the three first magnetic flux pulses are spaced 120 degrees apart.

[0130] Optionally, the processor may also execute program code with the following steps: before obtaining the values ​​of the dephase factors corresponding to the multiple first predetermined evolution durations after the qubit evolves based on a predetermined initial state at multiple first predetermined evolution durations, the processor includes: determining a fixed evolution duration and a second magnetic flux pulse; determining multiple third magnetic flux pulses that include the second magnetic flux pulse within a predetermined range near the second magnetic flux pulse; after the qubit evolves based on the predetermined initial state at a fixed evolution duration, applying the multiple third magnetic flux pulses to the qubit for projection measurement to obtain candidate values ​​of the dephase factors corresponding to the multiple third magnetic flux pulses; selecting the third magnetic flux pulse with the largest candidate value of the dephase factor among the multiple third magnetic flux pulses as the target magnetic flux pulse; fixing the qubit under the target magnetic flux pulse and evolving it based on the predetermined initial state at multiple first predetermined evolution durations.

[0131] Optionally, the processor may also execute program code for the following steps: determining the decoherence time of the qubit based on multiple first predetermined evolution durations and the values ​​of dephase factors corresponding to the multiple first predetermined evolution durations, including: obtaining a first relationship curve between the dephase factor and the duration based on multiple first predetermined evolution durations and the values ​​of dephase factors corresponding to the multiple first predetermined evolution durations; and determining the decoherence time of the qubit based on the first relationship curve.

[0132] Optionally, the processor may also execute program code with the following steps: based on multiple first predetermined evolution durations and the values ​​of the dephase factors corresponding to the multiple first predetermined evolution durations, obtain a first relationship curve between the dephase factors and the duration, including: determining the number of multiple first predetermined evolution durations and a first fitting function; based on the number of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the number of first predetermined evolution durations, using the first fitting function to obtain the first relationship curve between the dephase factors and the duration.

[0133] Optionally, the processor may also execute program code for the following steps: determining the decoherence time of the qubit based on the first relation curve, including: determining the target value of the dephase factor; and determining the duration corresponding to the target value on the first relation curve as the decoherence time of the qubit.

[0134] Optionally, the processor may also execute program code with the following steps: after determining the decoherence time of the qubit based on multiple first predetermined evolution durations and the values ​​of dephase factors corresponding to the multiple first predetermined evolution durations, it further includes: obtaining the values ​​of the decoherence time obtained by the qubit evolving under multiple fourth magnetic flux pulses; and obtaining a second relationship curve between the decoherence time and the magnetic flux pulse based on the values ​​of the decoherence time corresponding to the multiple fourth magnetic flux pulses.

[0135] Optionally, the processor may also execute program code for the following steps: obtaining the initial frequencies of the qubit under multiple fifth magnetic flux pulses; obtaining the phase change rate of the qubit under multiple applied fifth magnetic flux pulses; obtaining the frequency values ​​corresponding to the multiple fifth magnetic flux pulses based on the initial frequencies and phase change rates corresponding to the multiple fifth magnetic flux pulses; and obtaining a third relationship curve between the frequency of the qubit and the magnetic flux pulses based on the multiple fifth magnetic flux pulses and their corresponding frequency values.

[0136] Optionally, the processor may also execute program code for the following steps: obtaining the phase change rate of the qubit under the application of multiple fifth magnetic flux pulses, including: for any fifth magnetic flux pulse among the multiple fifth magnetic flux pulses, obtaining the phase value of the qubit after evolving for multiple second predetermined evolution times under any fifth magnetic flux pulse; determining the phase change rate of the qubit under any fifth magnetic flux pulse based on the multiple second predetermined evolution times and the phase values ​​corresponding to the multiple second predetermined evolution times; and obtaining the phase change rate of the qubit under the application of multiple fifth magnetic flux pulses by using the method of obtaining the phase change rate of any fifth magnetic flux pulse.

[0137] Optionally, the processor may also execute program code for the following steps: obtaining the phase value of the qubit after evolving for multiple second predetermined evolution periods under any fifth magnetic flux pulse, including: determining a sixth magnetic flux pulse corresponding to any fifth magnetic flux pulse for any second predetermined evolution period among the multiple second predetermined evolution periods, wherein the sixth magnetic flux pulse has the same amplitude as any fifth magnetic flux pulse, but the corresponding projected phase is different; after the qubit evolves for any second predetermined evolution period based on a predetermined initial state, applying any fifth magnetic flux pulse and the sixth magnetic flux pulse to the qubit for projection measurement, respectively, to obtain a second measurement result of any fifth magnetic flux pulse and a third measurement result corresponding to the sixth magnetic flux pulse; obtaining the phase value corresponding to any second predetermined evolution period based on the second measurement result of any fifth magnetic flux pulse and the third measurement result corresponding to the sixth magnetic flux pulse; obtaining the phase value of the qubit after evolving for multiple second predetermined evolution periods under any fifth magnetic flux pulse by using the method of obtaining the phase value corresponding to any second predetermined evolution period.

[0138] Optionally, the processor may also execute program code for the following steps: determining the phase change rate of the qubit in any fifth magnetic flux pulse based on a plurality of second predetermined evolution durations and phase values ​​corresponding to the plurality of second predetermined evolution durations, including: selecting two target second predetermined evolution durations from the plurality of second predetermined evolution durations, and determining the duration difference between the two target second predetermined evolution durations; determining the phase difference between the phase values ​​corresponding to the two target second predetermined evolution durations; and determining the phase change rate of the qubit in any fifth magnetic flux pulse based on the phase difference and the duration difference.

[0139] Optionally, the processor may also execute program code for the following steps: the qubit is a Fluxonium qubit.

[0140] The processor can invoke information and application programs stored in the memory via a transmission device to perform the following steps: displaying a qubit selection control on an interactive interface; displaying a target qubit on the interactive interface in response to an operation on the qubit selection control; receiving a decoherence time request for the target qubit; determining the decoherence time of the target qubit in response to the decoherence time request, wherein the decoherence time is obtained based on a plurality of first predetermined evolution durations and the values ​​of dephase factors corresponding to the plurality of first predetermined evolution durations, the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations being obtained after the target qubit evolves based on a predetermined initial state under the plurality of first predetermined evolution durations; and displaying the decoherence time on the interactive interface.

[0141] Those skilled in the art will understand that Figure 12 The structure shown is for illustrative purposes only. The computer terminal can also be a smartphone (such as an Android phone, an iOS phone, etc.), a tablet computer, a mobile internet device (MID), a PAD, and other terminal devices. Figure 12 This does not limit the structure of the aforementioned electronic device. For example, computer terminal 12 may also include components that are more advanced than those described above. Figure 12 The more or fewer components shown (such as network interfaces, display devices, etc.), or having the same Figure 12 The different configurations shown.

[0142] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing the hardware related to the terminal device. The program can be stored in a computer-readable storage medium, which may include: flash drive, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, etc.

[0143] Example 4

[0144] Embodiments of the present invention also provide a computer-readable storage medium. Optionally, in this embodiment, the computer-readable storage medium can be used to store the program code executed by the quantum bit processing method provided in Embodiment 1.

[0145] Optionally, in this embodiment, the computer-readable storage medium may be located in any computer terminal in a group of computer terminals in a computer network, or in any mobile terminal in a group of mobile terminals.

[0146] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: obtaining the values ​​of dephase factors corresponding to the multiple first predetermined evolution durations after the qubit evolves based on a predetermined initial state at multiple first predetermined evolution durations; determining the decoherence time of the qubit based on the multiple first predetermined evolution durations and the values ​​of the dephase factors corresponding to the multiple first predetermined evolution durations.

[0147] Optionally, in this embodiment, the computer-readable storage medium is further configured to store program code for performing the following steps: obtaining the values ​​of dephase factors corresponding to the multiple first predetermined evolution durations after the qubit evolves based on a predetermined initial state for each of the multiple first predetermined evolution durations, including: for any one of the multiple first predetermined evolution durations, after the qubit evolves based on the predetermined initial state for any one of the first predetermined evolution durations, applying multiple first magnetic flux pulses to the qubit for projection measurement to obtain first measurement results corresponding to the multiple first magnetic flux pulses; obtaining the value of the dephase factor corresponding to any one of the first predetermined evolution durations based on the first measurement results corresponding to the multiple first magnetic flux pulses; and obtaining the values ​​of the dephase factors corresponding to the multiple first predetermined evolution durations by using the method of obtaining the value of the dephase factor corresponding to any one of the first predetermined evolution durations.

[0148] Optionally, in this embodiment, the computer-readable storage medium is further configured to store program code for performing the following steps: the plurality of first magnetic flux pulses are three, and the phases of the projection measurements corresponding to the three first magnetic flux pulses are sequentially spaced 120 degrees apart.

[0149] Optionally, in this embodiment, the computer-readable storage medium is further configured to store program code for performing the following steps: before obtaining the values ​​of the dephase factors corresponding to the multiple first predetermined evolution durations after the qubit evolves based on a predetermined initial state at multiple first predetermined evolution durations, the method includes: determining a fixed evolution duration and a second magnetic flux pulse; determining multiple third magnetic flux pulses that include the second magnetic flux pulse within a predetermined range near the second magnetic flux pulse; after the qubit evolves based on the predetermined initial state at a fixed evolution duration, applying the multiple third magnetic flux pulses to the qubit for projection measurement to obtain candidate values ​​of the dephase factors corresponding to the multiple third magnetic flux pulses; selecting the third magnetic flux pulse with the largest candidate value of the dephase factor among the multiple third magnetic flux pulses as the target magnetic flux pulse; fixing the qubit under the target magnetic flux pulse and evolving it based on the predetermined initial state at multiple first predetermined evolution durations.

[0150] Optionally, in this embodiment, the computer-readable storage medium is further configured to store program code for performing the following steps: obtaining a first relationship curve between the dephase factor and the duration based on a plurality of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations; and determining the decoherence time of the qubit based on the first relationship curve.

[0151] Optionally, in this embodiment, the computer-readable storage medium is further configured to store program code for performing the following steps: obtaining a first relationship curve between the dephase factor and the duration based on a plurality of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations, including: determining the number of the plurality of first predetermined evolution durations and a first fitting function; and obtaining the first relationship curve between the dephase factor and the duration based on the number of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the number of first predetermined evolution durations, using the first fitting function.

[0152] Optionally, in this embodiment, the computer-readable storage medium is further configured to store program code for performing the following steps: determining the decoherence time of the qubit based on the first relation curve, including: determining a target value of the dephase factor; determining the duration corresponding to the target value on the first relation curve as the decoherence time of the qubit.

[0153] Optionally, in this embodiment, the computer-readable storage medium is further configured to store program code for performing the following steps: after determining the decoherence time of the qubit based on a plurality of first predetermined evolution durations and the values ​​of dephase factors corresponding to the plurality of first predetermined evolution durations, the method further includes: obtaining the values ​​of the decoherence time obtained by the qubit evolving under a plurality of fourth magnetic flux pulses; and obtaining a second relationship curve between the decoherence time and the magnetic flux pulse based on the values ​​of the decoherence time corresponding to the plurality of fourth magnetic flux pulses.

[0154] Optionally, in this embodiment, the computer-readable storage medium is further configured to store program code for performing the following steps: obtaining the initial frequencies of the qubit under multiple fifth magnetic flux pulses; obtaining the phase change rate of the qubit under multiple applied fifth magnetic flux pulses; obtaining the frequency values ​​corresponding to the multiple fifth magnetic flux pulses based on the initial frequencies corresponding to the multiple fifth magnetic flux pulses and the phase change rates corresponding to the multiple fifth magnetic flux pulses; and obtaining a third relationship curve between the frequency of the qubit and the magnetic flux pulses based on the multiple fifth magnetic flux pulses and the frequency values ​​corresponding to the multiple fifth magnetic flux pulses.

[0155] Optionally, in this embodiment, the computer-readable storage medium is further configured to store program code for performing the following steps: obtaining the phase change rate of the qubit under the application of a plurality of fifth magnetic flux pulses, including: for any fifth magnetic flux pulse among the plurality of fifth magnetic flux pulses, obtaining the phase value of the qubit after evolving for a plurality of second predetermined evolution durations under any fifth magnetic flux pulse; determining the phase change rate of the qubit under any fifth magnetic flux pulse based on the plurality of second predetermined evolution durations and the phase values ​​corresponding to the plurality of second predetermined evolution durations; and obtaining the phase change rate of the qubit under the application of a plurality of fifth magnetic flux pulses by using the method of obtaining the phase change rate of any fifth magnetic flux pulse.

[0156] Optionally, in this embodiment, the computer-readable storage medium is further configured to store program code for performing the following steps: obtaining the phase value of the qubit after evolving for multiple second predetermined evolution periods under any fifth magnetic flux pulse, including: determining a sixth magnetic flux pulse corresponding to any fifth magnetic flux pulse for any second predetermined evolution period among the multiple second predetermined evolution periods, wherein the sixth magnetic flux pulse has the same amplitude as any fifth magnetic flux pulse, but the corresponding projection measurement phases are different; after the qubit evolves for any second predetermined evolution period based on a predetermined initial state, applying any fifth magnetic flux pulse and the sixth magnetic flux pulse to the qubit for projection measurement, respectively, to obtain a second measurement result of any fifth magnetic flux pulse and a third measurement result corresponding to the sixth magnetic flux pulse; obtaining the phase value corresponding to any second predetermined evolution period based on the second measurement result of any fifth magnetic flux pulse and the third measurement result corresponding to the sixth magnetic flux pulse; obtaining the phase value of the qubit after evolving for multiple second predetermined evolution periods under any fifth magnetic flux pulse by using the method of obtaining the phase value corresponding to any second predetermined evolution period.

[0157] Optionally, in this embodiment, the computer-readable storage medium is further configured to store program code for performing the following steps: determining the phase change rate of the qubit in any fifth magnetic flux pulse based on a plurality of second predetermined evolution durations and phase values ​​corresponding to the plurality of second predetermined evolution durations, including: selecting two target second predetermined evolution durations from the plurality of second predetermined evolution durations, and determining the duration difference between the two target second predetermined evolution durations; determining the phase difference between the phase values ​​corresponding to the two target second predetermined evolution durations; and determining the phase change rate of the qubit in any fifth magnetic flux pulse based on the phase difference and the duration difference.

[0158] Optionally, in this embodiment, the computer-readable storage medium is further configured to store program code for performing the following steps: the qubits are Fluxonium qubits.

[0159] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: displaying a qubit selection control on an interactive interface; displaying a target qubit on the interactive interface in response to an operation on the qubit selection control; receiving a decoherence time request for the target qubit; determining the decoherence time of the target qubit in response to the decoherence time request, wherein the decoherence time is obtained based on a plurality of first predetermined evolution durations and the values ​​of dephase factors corresponding to the plurality of first predetermined evolution durations, the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations being obtained after the target qubit evolves based on a predetermined initial state under the plurality of first predetermined evolution durations; and displaying the decoherence time on the interactive interface.

[0160] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0161] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0162] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0163] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0164] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0165] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a computer-readable storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned computer-readable storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0166] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for processing quantum bits, characterized in that, include: The values ​​of the dephase factor corresponding to the multiple first predetermined evolution durations are obtained after the qubit evolves based on a predetermined initial state at multiple predetermined evolution durations, wherein the predetermined initial state is prepared by applying a magnetic flux pulse to the qubit, and the qubit is a Fluxonium qubit; The decoherence time of the qubit is determined based on the plurality of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations. The step of obtaining the dephase factor value corresponding to the multiple first predetermined evolution durations after the qubit evolves based on the predetermined initial state for each of the multiple first predetermined evolution durations includes: for any one of the multiple first predetermined evolution durations, after the qubit evolves based on the predetermined initial state for any one of the first predetermined evolution durations, applying multiple first magnetic flux pulses to the qubit for projection measurement to obtain the first measurement result corresponding to the multiple first magnetic flux pulses, wherein the projection measurement is to project the qubit into a specific direction for measurement; Based on the first measurement results corresponding to the plurality of first magnetic flux pulses, the value of the dephase factor corresponding to any first predetermined evolution time is obtained, wherein the plurality of first magnetic flux pulses are pulses with the same amplitude; The values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations are obtained by obtaining the values ​​of the dephase factors corresponding to any one of the first predetermined evolution durations. The step, before obtaining the values ​​of the dephase factor corresponding to the multiple first predetermined evolution durations after the qubit evolves based on a predetermined initial state at multiple predetermined evolution durations, includes: Determine the fixed evolution duration and the second magnetic flux pulse; Determine a plurality of third magnetic flux pulses that include the second magnetic flux pulse within a predetermined range near the second magnetic flux pulse; After the qubit evolves based on the predetermined initial state under the fixed evolution time, the plurality of third magnetic flux pulses are applied to the qubit for projection measurement to obtain candidate values ​​of the dephase factor corresponding to the plurality of third magnetic flux pulses; The third magnetic flux pulse with the largest candidate value of the dephase factor among the plurality of third magnetic flux pulses is selected as the target magnetic flux pulse; The qubit is fixed under the target magnetic flux pulse and evolves based on the predetermined initial state under the multiple first predetermined evolution durations, wherein the evolution is the process by which the qubit is affected by the environment in its environment.

2. The method according to claim 1, characterized in that, The plurality of first magnetic flux pulses are three, and the phases of the projection measurements corresponding to the three first magnetic flux pulses are sequentially spaced 120 degrees apart.

3. The method according to claim 1, characterized in that, Determining the decoherence time of the qubit based on the plurality of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations includes: Based on the plurality of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations, a first relationship curve between the dephase factors and the duration is obtained; Based on the first relationship curve, the decoherence time of the qubit is determined.

4. The method according to claim 3, characterized in that, The step of obtaining a first relationship curve between the dephase factor and the duration based on the plurality of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations includes: Determine the number of the plurality of first predetermined evolution durations, and the first fitting function; Based on the first predetermined evolution duration of the quantity and the value of the dephase factor corresponding to the first predetermined evolution duration, the first fitting function is used to obtain the first relationship curve between the dephase factor and the duration.

5. The method according to claim 3, characterized in that, Determining the decoherence time of the qubit based on the first relationship curve includes: Determine the target value of the dephase factor; The duration corresponding to the target value on the first relationship curve is determined to be the decoherence time of the quantum bit.

6. The method according to claim 1, characterized in that, After determining the decoherence time of the qubit based on the plurality of first predetermined evolution durations and the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations, the method further includes: The values ​​of the decoherence time are obtained by acquiring the evolution of the qubit under multiple fourth magnetic flux pulses; Based on the values ​​of the decoherence time corresponding to the plurality of fourth magnetic flux pulses, a second relationship curve between the decoherence time and the magnetic flux pulse is obtained.

7. The method according to claim 1, characterized in that, The method further includes: Obtain the initial frequencies of the quantum bit under multiple fifth magnetic flux pulses; Obtain the phase change rate of the qubit under the application of the plurality of fifth magnetic flux pulses respectively; Based on the initial frequencies corresponding to the plurality of fifth magnetic flux pulses and the phase change rates corresponding to the plurality of fifth magnetic flux pulses, the frequency values ​​corresponding to the plurality of fifth magnetic flux pulses are obtained. Based on the plurality of fifth magnetic flux pulses and the frequency values ​​corresponding to the plurality of fifth magnetic flux pulses, a third relationship curve between the frequency of the quantum bit and the magnetic flux pulses is obtained.

8. The method according to claim 7, characterized in that, The step of obtaining the phase change rate of the qubit under the application of the plurality of fifth magnetic flux pulses includes: For any one of the plurality of fifth magnetic flux pulses, obtain the phase value of the quantum bit after it has evolved for a plurality of second predetermined evolution times under any one of the fifth magnetic flux pulses; Based on the plurality of second predetermined evolution durations and the phase values ​​corresponding to the plurality of second predetermined evolution durations respectively, the phase change rate of the quantum bit in any fifth magnetic flux pulse is determined; The phase change rate of the qubit under the application of the plurality of fifth magnetic flux pulses is obtained by using the method of obtaining the phase change rate of any fifth magnetic flux pulse.

9. The method according to claim 8, characterized in that, The step of obtaining the phase value of the quantum bit after it has evolved through multiple second predetermined evolution times under any fifth magnetic flux pulse includes: For any one of the plurality of second predetermined evolution durations, a sixth magnetic flux pulse corresponding to any one of the fifth magnetic flux pulses is determined, wherein the sixth magnetic flux pulse has the same amplitude as any one of the fifth magnetic flux pulses, but the corresponding projection measurement phases are different; After the qubit evolves for any second predetermined evolution time based on the predetermined initial state, the fifth magnetic flux pulse and the sixth magnetic flux pulse are respectively applied to the qubit for projection measurement to obtain the second measurement result of the fifth magnetic flux pulse and the third measurement result corresponding to the sixth magnetic flux pulse; Based on the second measurement result of any fifth magnetic flux pulse and the third measurement result corresponding to the sixth magnetic flux pulse, the phase value corresponding to any second predetermined evolution duration is obtained; The phase value of the qubit after evolving for multiple second predetermined evolution durations under any fifth magnetic flux pulse is obtained by using the method of obtaining the phase value corresponding to any second predetermined evolution duration.

10. The method according to claim 8, characterized in that, Determining the phase change rate of the qubit in any fifth magnetic flux pulse based on the plurality of second predetermined evolution durations and the phase values ​​corresponding to the plurality of second predetermined evolution durations includes: Select two target second predetermined evolution durations from the plurality of second predetermined evolution durations, and determine the duration difference between the two target second predetermined evolution durations; Determine the phase difference between the phase values ​​corresponding to the second predetermined evolution durations of the two targets, respectively; Based on the phase difference and the duration difference, the phase change rate of the quantum bit in any fifth magnetic flux pulse is determined.

11. A method for processing quantum bits, characterized in that, include: Display the quantum bit selection control on the interactive interface; In response to an operation of the qubit selection control, the target qubit is displayed on the interactive interface; Receive a decoherence time request for the target qubit; In response to the decoherence time request, the decoherence time of the target qubit is determined, wherein the decoherence time is obtained based on a plurality of first predetermined evolution durations and the values ​​of dephase factors corresponding to the plurality of first predetermined evolution durations, wherein the values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations are obtained by the target qubit evolving based on a predetermined initial state under the plurality of first predetermined evolution durations, wherein the predetermined initial state is prepared by applying a magnetic flux pulse to the qubit, and the qubit is a Fluxonium qubit; The decoherence time is displayed on the interactive interface; The values ​​of the dephase factors corresponding to the plurality of first predetermined evolution durations are obtained by obtaining the values ​​of the dephase factors corresponding to any one of the first predetermined evolution durations. The values ​​of the dephase factors corresponding to any one of the first predetermined evolution durations are obtained based on the first measurement results corresponding to the plurality of first magnetic flux pulses. The first measurement results corresponding to the plurality of first magnetic flux pulses are obtained by applying the plurality of first magnetic flux pulses to the qubit for projection measurement after the qubit evolves for any one of the plurality of first predetermined evolution durations based on the predetermined initial state. The process, before obtaining the values ​​of the dephase factor corresponding to the multiple first predetermined evolution durations after the qubit evolves based on a predetermined initial state, includes: Determine the fixed evolution duration and the second magnetic flux pulse; Determine a plurality of third magnetic flux pulses that include the second magnetic flux pulse within a predetermined range near the second magnetic flux pulse; After the qubit evolves based on the predetermined initial state under the fixed evolution time, the plurality of third magnetic flux pulses are applied to the qubit for projection measurement to obtain candidate values ​​of the dephase factor corresponding to the plurality of third magnetic flux pulses; The third magnetic flux pulse with the largest candidate value of the dephase factor among the plurality of third magnetic flux pulses is selected as the target magnetic flux pulse; The qubit is fixed under the target magnetic flux pulse and evolves based on the predetermined initial state under the multiple first predetermined evolution durations, wherein the evolution is the process by which the qubit is affected by the environment in its environment.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the quantum bit processing method according to any one of claims 1 to 11.

13. A computer device, characterized in that, include: Memory and processor The memory stores computer programs; The processor is configured to execute a computer program stored in the memory, wherein when the computer program is executed, the processor performs the quantum bit processing method according to any one of claims 1 to 11.

Images