Method and device for removing polarization noise of quantum circuit, and electronic equipment

Abstract

The invention provides a quantum circuit polarization noise removal method and device, electronic equipment and a non-instantaneous computer readable storage medium, and the method comprises the steps: responding to a quantum circuit polarization noise removal instruction, testing a quantum circuit, and obtaining a test result; according to the test result, the distribution of quantum states in the quantum circuit is counted, and the quantum states comprise a physical state and a non-physical state; calculating the offset of the non-physical state by using the distribution of the non-physical state in the quantum circuit; and correcting the distribution of the physical state by using the offset of the non-physical state. According to the embodiment of the application, the measurement distribution offset of the quantum circuit caused by depolarization noise is calculated by using the non-physical state in the quantum circuit, and the physical state distribution of the quantum circuit is corrected by using the offset, so that the quantum state distribution error caused by depolarization noise in the quantum circuit is rapidly corrected.

Description

Technical Field

[0001] The present application relates to the field of quantum computing, and in particular, to a method and device for removing polarization noise of a quantum circuit, an electronic device, and a non-transient computer-readable storage medium. Background Art

[0002] Currently, quantum computers are in the NISQ (noisy intermediate scale) era. This means that due to the existence of noise, the number of available quantum bits, the depth of quantum circuits, and the fidelity of quantum gates are all subject to certain limitations. Quantum error correction technology is considered to be the ultimate solution to such problems.

[0003] Quantum error correction and quantum error mitigation are two different technical routes. Since quantum error correction is difficult to achieve at the current stage, error mitigation is a very important technical path. And even if quantum error correction is achieved, quantum error mitigation technology can still further enhance the effect of quantum error correction. Error mitigation technology does not directly reduce the noise of quantum circuits, but increases the types of circuits that need to be measured to achieve the prediction of results in a noise-free state. Therefore, error mitigation technology often requires a large increase in the number of circuit measurements, thereby extending the overall time of the experiment. At present, representative methods of error mitigation technology include zero noise extrapolation, probabilistic error elimination, and so on. Each solution has its own characteristics and limitations. In practical applications, there is no universal error mitigation technology, and each solution can only work within a specific range.

[0004] Since most error mitigation techniques improve accuracy by increasing the number of measurements, the original computing efficiency is reduced. Summary of the invention

[0005] The present application aims to propose a method and device for removing polarization noise of a quantum circuit, an electronic device, and a non-transient computer-readable storage medium, so as to solve the measurement error caused by the mixing of various types of noise in the quantum circuit.

[0006] According to one aspect of the present application, a method for removing polarization noise of a quantum circuit includes: in response to an instruction for removing polarization noise of a quantum circuit, testing the quantum circuit to obtain a test result; based on the test result, statistically analyzing the distribution of quantum states in the quantum circuit, wherein the quantum states include physical states and non-physical states; calculating an offset of the non-physical state using the distribution of the non-physical state in the quantum circuit; and correcting the distribution of the physical state using the offset of the non-physical state.

[0007] According to some embodiments, before testing the quantum circuit and obtaining the test result, the process further includes: acquiring quantum state information of the quantum circuit.

[0008] According to some embodiments, the distribution of quantum states comprises the number of occurrences of different quantum states in the quantum circuit.

[0009] According to some embodiments, calculating the offset of the non-physical state using the distribution of the non-physical state in the quantum circuit includes: calculating an average value of the number of occurrences of the non-physical state in the quantum circuit as the offset of the non-physical state.

[0010] According to some embodiments, the distribution of the physical state is corrected using the offset of the non-physical state, including: obtaining a first correction number of the physical state by subtracting the offset of the non-physical state from the number of occurrences of the physical state; setting the value of the correction number of the physical state whose first correction number is less than zero to zero to obtain a second correction number; calculating a normalization coefficient using the second correction number; and correcting the second correction number using the normalization coefficient.

[0011] According to some embodiments, calculating a normalization coefficient using the second correction number includes: adding the second correction number to obtain the normalization coefficient.

[0012] According to some embodiments, correcting the second correction number using the normalization coefficient includes: dividing the second correction number by the normalization coefficient to correct the second correction number.

[0013] According to one aspect of the present application, a device for removing polarization noise of a quantum circuit is proposed, comprising: a testing unit, for testing the quantum circuit in response to an instruction for removing polarization noise of the quantum circuit to obtain a test result; a statistical unit, for statistically analyzing the distribution of quantum states in the quantum circuit according to the test result, wherein the quantum states include physical states and non-physical states; an offset calculation unit, for calculating the offset of the non-physical state using the distribution of the non-physical state in the quantum circuit; and a correction unit, for correcting the distribution of the physical state using the offset of the non-physical state.

[0014] According to one aspect of the present application, an electronic device is provided, comprising: a processor; and a memory storing a computer program, wherein when the computer program is executed by the processor, the processor executes the removal method as described in any of the previous embodiments.

[0015] According to one aspect of the present application, a non-transitory computer-readable storage medium is provided, on which computer-readable instructions are stored. When the instructions are executed by a processor, the processor executes the removal method described in any of the previous embodiments.

[0016] According to an embodiment of the present application, a non-physical state in a quantum circuit is used to calculate a measurement distribution offset of the quantum circuit due to depolarization noise, and this offset is used to correct the physical state distribution of the quantum circuit, so as to quickly correct the quantum state distribution error caused by depolarization noise in the quantum circuit.

[0017] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. By describing the exemplary embodiments in detail with reference to the drawings, the above and other objectives, features and advantages of the present application will become more apparent.

[0019] Figure 1 A flow chart of a method for improving the efficiency of user shopping for goods according to an exemplary embodiment of the present application is shown.

[0020] Figure 2 A timing diagram of the interaction process of a user selecting a product according to an example embodiment of the application is shown.

[0021] Figure 3 A schematic diagram of page interaction according to an exemplary embodiment of the present application is shown.

[0022] Figure 4 A block diagram of a device for improving the efficiency of user shopping for goods according to an exemplary embodiment of the present application is shown.

[0023] Figure 5 An electronic device according to an exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0024] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. In the figures, the same figures show the same or similar parts, and thus their repeated description will be omitted.

[0025] The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0026] The described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of these specific details, or other modes, components, materials, devices or operations may be adopted. In these cases, known structures, methods, devices, implementations, materials or operations will not be shown or described in detail.

[0027] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0028] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0029] The specific embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0030] Figure 1 A flow chart of a method for removing polarization noise of a quantum circuit according to an exemplary embodiment of the present application is shown, as shown in FIG. Figure 1 The removal method shown includes steps S101 , S103 , S105 and S107 .

[0031] In step S101, in response to a quantum circuit polarization noise removal instruction, the quantum circuit is tested to obtain a test result.

[0032] According to an embodiment of the present application, in step S101, the quantum circuit needs to be tested multiple times so that in step S103, the statistical results of the quantum state can be obtained. For example, 10,000 to 100,000 test operations are performed.

[0033] When performing many-body physics or quantum chemistry calculations, due to the physical limitations or symmetries of the quantum circuit itself, for example, conservation of electron number, conservation of electron spin, spatial symmetry of the research object, etc., there will be limitations on the quantum state distribution obtained by calculating the quantum circuit. Therefore, according to an embodiment of the present application, before step S101, it is also necessary to obtain the quantum state information of the quantum circuit.

[0034] In a specific embodiment, first, the parameter vector P0 of the single-bit gate is initialized, and the phase of the single bits in the quantum circuit is set to -2*P0 using a microwave device. Then, based on the physical limitations or symmetry of the quantum circuit, quantum state information with a probability of zero in the quantum circuit is obtained. Finally, based on the obtained quantum state information of the quantum circuit, quantum state information with a theoretical probability of zero is determined.

[0035] For example, if there are N single-bit gates with adjustable parameters in a quantum circuit, each gate has a parameter, and the parameter of the i-th gate is P0i, then the parameter vector P0 is as shown in formula (1). That is, an initial parameter is set for each gate with a parameter. In this embodiment, the phase of the single-bit gate in the quantum circuit is set to -2*P0 using a microwave device.

[0036] P0 = (P01, P02,…, P0N) (1)

[0037] In step S103, the distribution of quantum states in the quantum circuit is statistically analyzed according to the test results.

[0038] Since most quantum computing coding technologies (e.g., Jordan-Wigner, Parity, Bravity-Kitaev coding, etc.) always have coding redundancy space, there will always be some coding states whose theoretical probability of occurrence is zero. For example, in chemical or material calculations, the conservation of electron numbers will limit the number of times the 1 state and the 0 state appear in the measured state string, and the probability of the string that does not meet the number of times the 1 state and the 0 state appear is theoretically 0. In this application, we refer to quantum states with a theoretical probability of zero as non-physical states, and quantum states with a theoretical probability of non-zero as physical states.

[0039] According to an embodiment of the present application, in step S103, the statistical quantum state distribution includes quantum state distribution of physical states and non-physical states.

[0040] For an N-bit quantum circuit, all its quantum states include binary numbers from 00…0 to 11…1.

[0041] For example, consider a research object consisting of two molecular orbitals and one electron. Using Jordan-Wigner coding, it can be encoded as a two-qubit circuit. All of its quantum states are 00, 01, 10, and 11. Among them, quantum states 01 and 10 are physical states, and 00 and 11 are non-physical states.

[0042] For another example, consider a research object consisting of three molecular orbitals and two electrons. In the case of Jordan-Wigner coding, it can be encoded as a three-qubit circuit. All its quantum states are 000, 001, 010, 100, 011, 101, 110, and 111. Quantum states 011, 101, and 110 are physical states, and quantum states 000, 001, 010, 100, and 111 are non-physical states.

[0043] It should be noted that due to the physical limitations or symmetry of the quantum circuit itself, there are restrictions on the distribution of quantum states calculated by the quantum circuit. Therefore, the specific physical state and non-physical state are determined by the specific research problem and the encoded quantum circuit. Here, only for the convenience of understanding, examples of possible physical states and non-physical states are given. Therefore, this example cannot be understood as a limitation of this application.

[0044] In step S105, the offset of the non-physical state is calculated using the distribution of the non-physical state in the quantum circuit.

[0045] According to an embodiment of the present application, in step S105, the average value of the number of occurrences of the non-physical state in the quantum circuit is calculated as the offset of the non-physical state.

[0046] For example, for m non-physical states, the number of occurrences of each non-physical state is calculated and recorded as c(1), c(2), ..., c(m-1), and c(m). Finally, the average offset of the calculated non-physical state is shown in formula (2).

[0047] C={c(1)+c(2)+... +c(m-1)+c(m)} / m (2)

[0048] In step S107, the distribution of the physical state is corrected using the offset of the non-physical state.

[0049] According to an embodiment of the present application, step S107 includes: Figure 2 Sub-steps shown:

[0050] In sub-step S1071, the first correction number of the physical state is obtained by subtracting the offset of the non-physical state from the number of occurrences of the physical state;

[0051] In sub-step S1073, the value of the correction number in the physical state whose first correction number is less than zero is set to zero to obtain a second correction number;

[0052] In sub-step S1075, a normalization coefficient is calculated using the second correction number;

[0053] In sub-step S1077, the second correction number is corrected using the normalization coefficient.

[0054] According to an embodiment of the present application, in sub-step S1075, the second correction number is added to obtain a normalization coefficient, and in sub-step S1077, the second correction number is divided by the normalization coefficient to correct the second correction number.

[0055] For example, for n physical states, the number of occurrences of each physical state is calculated and recorded as d(1), d(2), ..., d(n-1) and d(n) respectively; then, the number of occurrences of each state is subtracted from the calculated non-physical state offset C to obtain a new distribution, that is, d(1)-C, d(2)-C, ..., d(n-1)-C and d(n)-C. The distributions at this time are marked as d(1)', d(2)', ..., d(n-1)', d(n)'. All items less than 0 in the new distribution are set to 0, that is, if d(2)-C<0, set d(2)'=0. Define a new normalization coefficient D=d(1)'+d(2)'+...+d(n-1)'+d(n)'. The new distribution is normalized using D to obtain the distribution of the modified physical state, that is, d(1)' / D, d(2)' / D, ..., d(n-1)' / D, d(n)' / D.

[0056] according to Figure 1 The embodiment shown uses a quantum state whose theoretical probability of occurrence in a quantum circuit is 0 to calculate the measurement distribution offset of the quantum circuit due to depolarization noise, and uses this offset to correct the quantum state distribution of the quantum circuit, so as to quickly correct the quantum state distribution error caused by depolarization noise in the quantum circuit.

[0057] According to the embodiments of the present application, without changing the quantum circuit and without increasing the number of quantum circuit measurements, the change in quantum state distribution caused by circuit depolarization noise is significantly corrected, and the measurement error caused by the mixing of various types of noise in the quantum circuit is reduced.

[0058] Figure 3 A schematic diagram of the total error rate of a quantum circuit according to an exemplary embodiment of the present application is shown, wherein the horizontal axis is the depth of the quantum circuit and the vertical axis is the total error rate of the quantum circuit. The dots are the total error rate obtained according to the exemplary embodiment of the present application, the triangles are the original unprocessed total error rate, and the squares are the total error rate without considering the non-physical state and only retaining the physical state.

[0059] like Figure 3 As shown, the total error rate obtained according to the exemplary embodiment of the present application is much lower than the total error rate of the original data and the total error rate when only the physical state is retained.

[0060] The above mainly introduces the embodiments of the present application from the perspective of the method. Those skilled in the art should easily appreciate that, in combination with the operations or steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Those skilled in the art can use different ways to implement the described functions for each specific operation or method, and such implementation should not be considered to be beyond the scope of the present application.

[0061] The following describes the device embodiments of the present application. For details not described in the device embodiments of the present application, reference can be made to the method embodiments of the present application.

[0062] Figure 4 A block diagram of a device for removing polarization noise of a quantum circuit according to an exemplary embodiment of the present application is shown, as shown in FIG. Figure 4 The removal device shown includes a test unit 401, a statistics unit 403, an offset calculation unit 405 and a correction unit 407. The test unit 401 is used to respond to the instruction for removing the polarization noise of the quantum circuit, test the quantum circuit, and obtain a test result; the statistics unit 403 is used to count the distribution of quantum states in the quantum circuit according to the test result, wherein the quantum state includes a physical state and a non-physical state; the offset calculation unit 405 is used to calculate the offset of the non-physical state using the distribution of the non-physical state in the quantum circuit; and the correction unit 407 is used to correct the distribution of the physical state using the offset of the non-physical state.

[0063] Figure 5 An electronic device according to an exemplary embodiment of the present application is shown. Figure 5 The electronic device 200 according to this embodiment of the present application is described. Figure 5 The electronic device 200 shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0064] like Figure 5 As shown, the electronic device 200 is in the form of a general computing device. The components of the electronic device 200 may include, but are not limited to: at least one processing unit 210, at least one storage unit 220, a bus 230 connecting different system components (including the storage unit 220 and the processing unit 210), a display unit 240, etc.

[0065] The storage unit stores program codes, which can be executed by the processing unit 210, so that the processing unit 210 executes the methods described in this specification according to various exemplary embodiments of the present application. For example, the processing unit 210 can execute the following: Figure 1 The method shown in .

[0066] The storage unit 220 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) 2201 and / or a cache memory unit 2202 , and may further include a read-only memory unit (ROM) 2203 .

[0067] The storage unit 220 may also include a program / utility 2204 having a set (at least one) of program modules 2205, such program modules 2205 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0068] Bus 230 may represent one or more of several types of bus structures, including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0069] The electronic device 200 may also communicate with one or more external devices 300 (e.g., keyboards, pointing devices, Bluetooth devices, etc.), may also communicate with one or more devices that enable a user to interact with the electronic device 200, and / or communicate with any device that enables the electronic device 200 to communicate with one or more other computing devices (e.g., routers, modems, etc.). Such communication may be performed via an input / output (I / O) interface 250. Furthermore, the electronic device 200 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 260. The network adapter 260 may communicate with other modules of the electronic device 200 via the bus 230. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device 200, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0070] Through the description of the above implementation methods, it is easy for those skilled in the art to understand that the example implementation methods described here can be implemented by software or by combining software with necessary hardware. The technical solution according to the implementation method of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, or a network device, etc.) to execute the above method according to the implementation method of the present application.

[0071] The software product may use any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0072] Computer readable storage media may include data signals propagated in baseband or as part of a carrier wave, wherein readable program codes are carried. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The readable storage medium may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, device, or device. The program codes contained on the readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination thereof.

[0073] Program code for performing the operations of the present application may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0074] The computer-readable medium carries one or more programs. When the one or more programs are executed by a device, the computer-readable medium implements the aforementioned functions.

[0075] Those skilled in the art will appreciate that the above modules can be distributed in the device according to the description of the embodiment, or can be changed accordingly and only used in one or more devices different from the embodiment. The modules of the above embodiments can be combined into one module, or further divided into multiple sub-modules.

[0076] According to an embodiment of the present application, a computer program is provided, including a computer program or an instruction. When the computer program or the instruction is executed by a processor, the method described above can be executed.

[0077] The embodiments of the present application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application. At the same time, changes or deformations made by those skilled in the art based on the ideas of the present application, the specific implementation methods and the scope of application of the present application, all belong to the scope of protection of the present application. In summary, the content of this specification should not be construed as a limitation on the present application.

Claims

1. A method for removing polarization noise of a quantum circuit, characterized in that: include: In response to the instruction to remove the polarization noise of the quantum circuit, the quantum circuit is tested to obtain a test result; According to the test results, counting the distribution of quantum states in the quantum circuit, wherein the quantum states include physical states and non-physical states; Calculating the offset of the non-physical state using the distribution of the non-physical state in the quantum circuit; The distribution of the physical state is corrected using the offset of the non-physical state.

2. The removal method according to claim 1, characterized in that: Before testing the quantum circuit and obtaining the test result, the method further includes: The quantum state information of the quantum circuit is obtained.

3. The removal method according to claim 1, characterized in that: The distribution of the quantum state includes the number of occurrences of different quantum states in the quantum circuit.

4. The removal method according to claim 3, characterized in that: Calculating the offset of the non-physical state using the distribution of the non-physical state in the quantum circuit comprises: The average value of the number of occurrences of the non-physical state in the quantum circuit is calculated as the offset of the non-physical state.

5. The removal method according to claim 4, characterized in that: Correcting the distribution of the physical state using the offset of the non-physical state includes: Subtracting the offset of the non-physical state from the number of occurrences of the physical state to obtain a first correction number of the physical state; The values ​​of the correction times in the physical state whose first correction times are less than zero are set to zero to obtain a second correction times; Calculating a normalization coefficient using the second correction number; The second correction number is corrected using the normalization coefficient.

6. The removal method according to claim 5, characterized in that: Calculating a normalization coefficient using the second correction number includes: The second correction times are added to obtain the normalization coefficient.

7. The removal method according to claim 6, characterized in that: Correcting the second correction number by using the normalization coefficient includes: The second correction number is divided by the normalization coefficient to correct the second correction number.

8. A device for removing polarization noise of a quantum circuit, characterized in that: include: A testing unit, configured to test the quantum circuit in response to a quantum circuit polarization noise removal instruction to obtain a test result; A statistical unit, configured to count the distribution of quantum states in the quantum circuit according to the test results, wherein the quantum states include physical states and non-physical states; An offset calculation unit, used to calculate the offset of the non-physical state using the distribution of the non-physical state in the quantum circuit; A correction unit is used to correct the distribution of the physical state using the offset of the non-physical state.

9. An electronic device, comprising: processor; as well as A memory storing a computer program, which, when executed by the processor, enables the processor to perform the removal method according to any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having computer-readable instructions stored thereon, which, when executed by a processor, causes the processor to execute the removal method according to any one of claims 1 to 7.

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