Quantum state property analysis method and quantum state property analysis device in distributed scenario

Abstract

The present disclosure provides a quantum state property analysis method and a quantum state property analysis device in a distributed scenario, the method comprising: for any one quantum terminal, generating a block encoding unitary matrix according to a preset purification operator, wherein there is no quantum communication behavior between different quantum terminals; performing function fitting processing on a target function to obtain a polynomial function; solving the polynomial function by using a Remez algorithm to obtain a phase tuple, wherein the phase tuple comprises a plurality of phase elements; applying a control gate to a singular value transformation circuit to obtain a control block encoding operator, wherein the singular value transformation circuit is obtained according to the number of phase elements and the block encoding unitary matrix; iteratively applying the control block encoding operator to a preset quantum state for measurement to obtain a plurality of measurement results; and generating unbiased estimation information in the distributed scenario according to the plurality of measurement results of different quantum terminals.

Description

Technical Field

[0001] This application relates to the field of quantum computing technology, and more specifically, to a method and apparatus for analyzing the properties of quantum states in a distributed scenario. Background Technology

[0002] As the availability of small quantum computers on different physical platforms increases, a task known as cross-platform verification has been proposed: aiming to estimate the properties of quantum states prepared on two quantum computers. Cross-platform verification is fundamentally a distributed task due to hardware limitations: quantum computers built on different routes cannot communicate quantumly, making joint SWAP tests impossible. Summary of the Invention

[0003] In view of this, this application provides a method and apparatus for analyzing the properties of quantum states in a distributed scenario.

[0004] One aspect of this application provides a method for analyzing the properties of quantum states in a distributed scenario, including:

[0005] For any quantum terminal, a block-encoded unitary matrix is ​​generated according to a preset purification operator, wherein there is no quantum communication behavior between different quantum terminals.

[0006] The objective function is fitted to obtain a polynomial function;

[0007] The Remez algorithm is used to solve the above polynomial function to obtain a phase tuple, which includes multiple phase elements.

[0008] The control gate is applied to the singular value transform circuit to obtain the control block coding operator, wherein the singular value transform circuit is obtained based on the number of phase elements and the block coding unitary matrix.

[0009] Based on the above control block encoding operator, iteratively applied to the preset quantum state to perform measurement, multiple measurement results are obtained;

[0010] Based on multiple measurement results from different quantum terminals, unbiased estimation information for the aforementioned distributed scenario is generated.

[0011] According to embodiments of this application, it also includes:

[0012] Calculate the fidelity and / or relative entropy of the quantum states between different quantum terminals based on the above unbiased estimation information.

[0013] According to embodiments of this application, applying a control gate to a singular value transform circuit to obtain a control block encoding operator includes:

[0014] The control gates are applied to each initial gate in the singular value transform circuit to obtain the control block encoding operator.

[0015] According to an embodiment of this application, the above-described singular value transformation circuit is generated in the following manner:

[0016] When the above quantity is odd, the first singular value transform circuit is generated according to the above quantity of phase elements and the above block-coded unitary matrix.

[0017] When the above quantity is even, a second singular value transformation circuit is generated based on the above number of phase elements and the above block-coded unitary matrix, wherein the above singular value transformation circuit includes the above first singular value transformation circuit or the above second singular value transformation circuit.

[0018] According to embodiments of this application, based on the iterative application of the above-described control block encoding operator to a preset quantum state for measurement, multiple measurement results are obtained, including:

[0019] Two random matrices are randomly selected from the preset Haar random matrix for each of the aforementioned quantum terminals;

[0020] For any quantum terminal in the j-th iteration, the target state is generated when the control block encoding operator acts on the preset initial state and the Hadamard gate acts on the first qubit of the preset initial state, wherein the preset initial state is generated based on the two random matrices of the quantum terminal.

[0021] The target state is measured on the Z basis to obtain multiple measurement results corresponding to the j-th iteration, wherein one of the above measurement results corresponds to one of the above random matrices.

[0022] According to embodiments of this application, two random matrices are randomly selected from a preset Haar random matrix for each of the aforementioned quantum terminals, including:

[0023] For each of the aforementioned quantum terminals, the same first matrix is ​​randomly selected from the aforementioned preset Haar random matrix.

[0024] For each of the aforementioned quantum terminals, a different second matrix is ​​randomly selected from the aforementioned preset Haar random matrix.

[0025] According to embodiments of this application, unbiased estimation information for the aforementioned distributed scenario is generated based on multiple measurement results from different quantum terminals, including:

[0026] For each of the aforementioned quantum terminals, a dataset corresponding to each random matrix is ​​generated based on the multiple measurement results corresponding to the aforementioned quantum terminal.

[0027] For each of the above random matrices, statistical parameters corresponding to the above random matrices are generated based on the dataset corresponding to the above random matrices and the dimension of the density operator corresponding to the above preset purification operator.

[0028] The unbiased estimation information is generated based on the statistical parameters corresponding to different random matrices described above.

[0029] Another aspect of this application provides a quantum state property analysis device in a distributed scenario, comprising:

[0030] The first generation module is used to generate a block-encoded unitary matrix for any quantum terminal according to a preset purification operator, wherein there is no quantum communication behavior between different quantum terminals.

[0031] The fitting module is used to perform function fitting on the objective function to obtain a polynomial function.

[0032] The solver module is used to solve the above polynomial function using the Remez algorithm to obtain a phase tuple, wherein the phase tuple includes multiple phase elements;

[0033] A module is obtained to apply a control gate to a singular value transform circuit to obtain a control block coding operator, wherein the singular value transform circuit is obtained based on the number of phase elements and the block coding unitary matrix.

[0034] The measurement module is used to iteratively apply the control block encoding operator to a preset quantum state to perform measurements and obtain multiple measurement results.

[0035] The estimation module is used to generate unbiased estimation information for the above-mentioned distributed scenario based on multiple measurement results from different quantum terminals.

[0036] According to embodiments of this application, by processing preset purification operators and objective functions of different quantum terminals in a distributed scenario, corresponding block-coded unitary matrices and polynomial functions are obtained. The polynomial functions are solved to obtain phase tuples. A control gate is applied to a singular value transform circuit to obtain a control block-coded operator. This control block-coded operator is then iteratively applied to a preset quantum state for measurement, yielding multiple measurement results. These measurement results can then be used to calculate unbiased estimation information. The quantum state property analysis method of this application can be applied to the estimation of more types of quantum state properties while reducing query complexity. Attached Figure Description

[0037] The above and other objects, features and advantages of this application will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0038] Figure 1 A flowchart illustrating a quantum state property analysis method according to an embodiment of this application is shown schematically.

[0039] Figure 2 A schematic diagram of a quantum singular value transformation circuit according to an embodiment of this application is shown.

[0040] Figure 3 A block diagram of a quantum state property analysis apparatus according to an embodiment of this application is shown schematically. Detailed Implementation

[0041] The embodiments of this application will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of this application. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of this application for ease of explanation. However, it will be apparent that one or more embodiments may be implemented without these specific details. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of this application.

[0042] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0043] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0044] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0045] Existing work considers the sample complexity required to estimate the inner product of quantum states. Specifically, it considers Alice and Bob on two different physical platforms, each with unknown quantum states. and Replication of each The goal is to estimate using only local quantum operations and classical communication. And ensure that the estimated value differs from the actual value by at most 0.5%. The additive error.

[0046] However, in distributed scenarios, besides estimating the inner product of quantum states, there are still no suitable methods for estimating properties of interest such as the fidelity of quantum states and relative entropy. This is partly because current work focuses on sampling as the input model, with limited research on other input models; and partly because obtaining the matrix function from quantum circuits is also a challenging problem.

[0047] In view of this, this application provides a method and apparatus for analyzing the properties of quantum states in a distributed scenario. The method includes generating a block-coded unitary matrix for any quantum terminal according to a preset purification operator, wherein there is no quantum communication behavior between different quantum terminals; performing function fitting on the objective function to obtain a polynomial function; solving the polynomial function using the Remez algorithm to obtain a phase tuple, wherein the phase tuple includes multiple phase elements; applying a control gate to a singular value transform circuit to obtain a control block-coded operator, wherein the singular value transform circuit is obtained based on the number of phase elements and the block-coded unitary matrix; iteratively applying the control block-coded operator to a preset quantum state to perform measurements to obtain multiple measurement results; and generating unbiased estimation information in a distributed scenario based on the multiple measurement results from different quantum terminals.

[0048] In the embodiments of this application, the collection, updating, analysis, processing, use, transmission, provision, disclosure, and storage of data (e.g., including but not limited to user personal information) comply with relevant laws and regulations, are used for legitimate purposes, and do not violate public order and good morals. In particular, necessary measures have been taken to prevent unauthorized access to user personal information data and to safeguard user personal information security, network security, and national security.

[0049] Figure 1 A flowchart illustrating a quantum state property analysis method according to an embodiment of this application is shown schematically.

[0050] like Figure 1 As shown, the quantum state property analysis method in this distributed scenario includes operations S101~S105.

[0051] In operation S101, for any quantum terminal, a block-coded unitary matrix is ​​generated according to a preset purification operator, wherein there is no quantum communication behavior between different quantum terminals;

[0052] In operation S102, the objective function is fitted to obtain a polynomial function.

[0053] In operation S103, the Remez algorithm is used to solve the polynomial function to obtain the phase tuple, which includes multiple phase elements.

[0054] In operation S104, the control gate is applied to the singular value transform circuit to obtain the control block coding operator, wherein the singular value transform circuit is obtained based on the number of phase elements and the block coding unitary matrix;

[0055] In operation S105, the control block encoding operator is iteratively applied to the preset quantum state to perform measurements, resulting in multiple measurement results.

[0056] In operation S106, unbiased estimation information in a distributed scenario is generated based on multiple measurement results from different quantum terminals.

[0057] According to embodiments of this application, a distributed scenario refers to a scenario where multiple quantum terminals cannot communicate via quantum communication and can only communicate via classical communication.

[0058] In one specific embodiment, assuming there are two quantum terminals, Alice and Bob, for quantum terminal Alice, a preset purification operator is used. The block-coded unitary matrix can be obtained. Similarly, for the quantum terminal Bob, the block-coded unitary matrix is ​​obtained using a pre-defined purification operator. .in, , .

[0059] According to an embodiment of this application, the objective function is subjected to function fitting to obtain a polynomial function, and the Remez algorithm is used to solve the polynomial function to obtain a phase tuple, wherein the phase tuple includes multiple phase elements.

[0060] Specifically, in order to obtain matrix functions through quantum circuits, polynomial functions must be utilized. , To approximate separately and Thus, the polynomial function is obtained. , .

[0061] According to embodiments of this application, specifically, given , The number of times it exists is polynomial function and satisfy , , making The resulting polynomial function The phase tuples were obtained by solving the Remez algorithm. , .

[0062] According to embodiments of this application, the control gate is obtained based on the number of phase elements and the block-coded unitary matrix, and then... The control block encoding operator is applied to the singular value transform circuit. and .

[0063] According to embodiments of this application, for the quantum terminal Alice, based on control block coding operators...

[0064] Iteratively acting on a pre-defined quantum state to perform measurements yields multiple measurement results, such as... , Similarly, for the quantum terminal Bob, based on the control block coding operator... Iteratively acting on a pre-defined quantum state to perform measurements yields multiple measurement results, such as... , .

[0065] According to embodiments of this application, based on multiple measurement results from different quantum terminals , , , Generate unbiased estimation information T in a distributed scenario.

[0066] According to embodiments of this application, by processing preset purification operators and objective functions of different quantum terminals in a distributed scenario, corresponding block-coded unitary matrices and polynomial functions are obtained. The polynomial functions are solved to obtain phase tuples. A control gate is applied to a singular value transform circuit to obtain a control block-coded operator. This control block-coded operator is then iteratively applied to a preset quantum state for measurement, yielding multiple measurement results. These measurement results can then be used to calculate unbiased estimation information. The quantum state property analysis method of this application can be applied to the estimation of more types of quantum state properties while reducing query complexity.

[0067] According to embodiments of this application, applying a control gate to a singular value transform circuit to obtain a control block encoding operator includes:

[0068] The control gates are applied to each initial gate in the singular value transform circuit to obtain the control block encoding operator.

[0069] Figure 2 A schematic diagram of a quantum singular value transformation circuit according to an embodiment of this application is shown.

[0070] According to embodiments of this application, the singular value transformation circuit is generated in the following manner:

[0071] When the number of phase elements is odd, the first singular value transformation circuit is generated based on the number of phase elements and the block coding unitary matrix, and the first coding operator is generated.

[0072] When the number is even, a second singular value transformation circuit is generated based on the number of phase elements and the block-coded unitary matrix, wherein the singular value transformation circuit includes either a first singular value transformation circuit or a second singular value transformation circuit.

[0073] According to embodiments of this application, a quantum singular value transformation circuit (QSVT) is used to obtain... In this way, A similar result can be obtained. Among them, If the number of phase elements For odd numbers, see reference. Figure 2 The first singular value transform circuit is generated based on the number of phase elements and the block-coded unitary matrix. ,in Specifically, this manifests as: ,in, .

[0074] According to an embodiment of this application, if the number of phase elements If the number is even, similarly, based on the number of phase elements and the block-coded unitary matrix, a second singular value transform circuit is generated, which is as follows:

[0075] in, .

[0076] According to the embodiments of this application, it is guaranteed that .

[0077] According to an embodiment of this application, the control door... The initial control block encoding operator is obtained by applying it to each initial gate in the singular value transform circuit as a whole: . Similarly, the initial gate here refers to the unitary matrix and the SWAP gate mentioned above.

[0078] According to an embodiment of this application, let The final control block coding operator can be obtained. and .

[0079] According to embodiments of this application, measurements are performed by iteratively applying a control block coding operator to a preset quantum state, resulting in multiple measurement results, including:

[0080] Two random matrices are randomly selected for each quantum terminal from the preset Haar random matrix;

[0081] For any quantum terminal in the j-th iteration, the target state is generated when the control block encoding operator acts on the preset initial state and the Hadamard gate acts on the first qubit of the preset initial state. The preset initial state is generated based on two random matrices of the quantum terminal.

[0082] The target state is measured on the Z basis, and multiple measurement results corresponding to the j-th iteration are obtained, where each measurement result corresponds to a random matrix.

[0083] According to embodiments of this application, two random matrices are randomly selected from a preset Haar random matrix for each quantum terminal, including:

[0084] For each quantum terminal, a first matrix is ​​randomly selected from the preset Haar random matrix.

[0085] For each quantum terminal, a different second matrix is ​​randomly selected from the preset Haar random matrix.

[0086] According to embodiments of this application, from a preset Haar random matrix The first matrix is ​​randomly selected for Alice and Bob. ;from Alice randomly selects a second matrix. ;from Bob randomly selects a second matrix. ,in, Let be a random d-dimensional matrix of Hear.

[0087] According to an embodiment of this application, the following iteration needs to be performed m times. For the j-th iteration of the quantum terminal Alice, the control block encoding operator is... Acting on the preset initial state respectively , Then, a Hadamard gate is applied to the first qubit of the preset initial state to generate the target state. Multiple measurement results can be obtained by measuring the target state under the given conditions. and ,in .

[0088] According to the embodiments of this application, similarly for the j-th iteration of quantum terminal Bob, the control block encoding operator is... Acting on the preset initial state respectively , Then, the Hadamard gate is applied to the first qubit of the preset initial state to generate the target state. By measuring the target state under the given conditions, the measurement results can be obtained. and ,in .

[0089] According to embodiments of this application, unbiased estimation information in a distributed scenario is generated based on multiple measurement results from different quantum terminals, including:

[0090] For each quantum terminal, a dataset corresponding to each random matrix is ​​generated based on multiple measurement results corresponding to the quantum terminal;

[0091] For each random matrix, statistical parameters of the corresponding random matrix are generated based on the dataset corresponding to the random matrix and the dimension of the density operator corresponding to the preset purification operator.

[0092] Unbiased estimation information is generated based on multiple statistical parameters corresponding to different random matrices.

[0093] According to embodiments of this application, for each quantum terminal, a dataset corresponding to each random matrix is ​​generated based on multiple measurement results corresponding to the quantum terminal, such as the dataset for quantum terminal Alice. , The dataset of quantum terminal Bob , .

[0094] According to embodiments of this application, based on a dataset corresponding to a random matrix , , , The number of phase elements is used to generate the statistical parameters of the corresponding random matrix. Specifically:

[0095] make , ,

[0096] .remember .

[0097] According to the embodiments of this application, finally according to Generate unbiased estimation information , That is to An unbiased estimate.

[0098] According to embodiments of this application, the quantum state property analysis method further includes:

[0099] Calculate the fidelity and / or relative entropy of quantum states between different quantum terminals based on unbiased estimation information.

[0100] According to embodiments of this application, in a distributed scenario, unbiased estimation information can also be used. Fidelity of quantum state calculation and relative entropy .

[0101] Figure 3 A block diagram of a quantum state property analysis apparatus according to an embodiment of this application is shown schematically.

[0102] like Figure 3 As shown, the quantum state property analysis device 300 in a distributed scenario includes a first generation module 310, a fitting module 320, a solution module 330, an acquisition module 340, a measurement module 350, and an estimation module 360.

[0103] The first generation module 310 is used to generate a block-encoded unitary matrix for any quantum terminal according to a preset purification operator, wherein there is no quantum communication behavior between different quantum terminals;

[0104] The fitting module 320 is used to perform function fitting on the objective function to obtain a polynomial function.

[0105] The solver module 330 is used to solve the polynomial function using the Remez algorithm to obtain a phase tuple, wherein the phase tuple includes multiple phase elements;

[0106] Module 340 is obtained, which is used to apply the control gate to the singular value transform circuit to obtain the control block coding operator, wherein the singular value transform circuit is obtained based on the number of phase elements and the block coding unitary matrix;

[0107] The measurement module 350 is used to perform measurements by iteratively applying a control block encoded operator to a preset quantum state to obtain multiple measurement results.

[0108] The estimation module 360 ​​is used to generate unbiased estimation information in a distributed scenario based on multiple measurement results from different quantum terminals.

[0109] According to embodiments of this application, by processing preset purification operators and objective functions of different quantum terminals in a distributed scenario, corresponding block-coded unitary matrices and polynomial functions are obtained. The polynomial functions are solved to obtain phase tuples. A control gate is applied to a singular value transform circuit to obtain a control block-coded operator. This control block-coded operator is then iteratively applied to a preset quantum state for measurement, yielding multiple measurement results. These measurement results can then be used to calculate unbiased estimation information. The quantum state property analysis method of this application can be applied to the estimation of more types of quantum state properties while reducing query complexity.

[0110] According to embodiments of this application, the quantum state property analysis device 300 further includes:

[0111] The computation module is used to calculate the fidelity and / or relative entropy of quantum states between different quantum terminals based on unbiased estimation information.

[0112] According to an embodiment of this application, module 340 includes:

[0113] A unit is obtained to apply control gates to each initial gate in the singular value transform circuit to obtain a control block encoding operator.

[0114] According to embodiments of this application, the singular value transformation circuit is generated in the following manner:

[0115] The first generation unit is used to generate a first singular value transformation circuit and generate a first encoding operator when the number of phase elements is odd, based on the number of phase elements and the block coding unitary matrix.

[0116] The second generation unit is used to generate a second singular value transformation circuit based on the number of phase elements and the block-coded unitary matrix when the number of elements is even. The singular value transformation circuit includes either a first singular value transformation circuit or a second singular value transformation circuit.

[0117] According to an embodiment of this application, the measurement module 350 includes:

[0118] The random unit is used to randomly select two random matrices from the preset Haar random matrix for each quantum terminal;

[0119] The fifth generation unit is used to generate the target state for the j-th iteration of any quantum terminal, with the control block encoding operator acting on the preset initial state and the Hadamard gate acting on the first qubit of the preset initial state. The preset initial state is generated based on two random matrices of the quantum terminal.

[0120] The sixth generation unit is used to measure the target state on the Z basis and obtain multiple measurement results corresponding to the j-th iteration, where each measurement result corresponds to a random matrix.

[0121] According to an embodiment of this application, the random unit includes:

[0122] The first random subunit is used to randomly select the same first matrix for each quantum terminal from a preset Haar random matrix;

[0123] The second random subunit is used to randomly select a different second matrix from the preset Haar random matrix for each quantum terminal.

[0124] According to an embodiment of this application, the estimation module 360 ​​includes:

[0125] The seventh generation unit is used to generate a dataset corresponding to each random matrix for each quantum terminal based on multiple measurement results corresponding to the quantum terminal.

[0126] The eighth generation unit is used to generate statistical parameters for each random matrix based on the dataset corresponding to the random matrix and the dimension of the density operator corresponding to the preset purification operator.

[0127] The ninth generation unit is used to generate unbiased estimation information based on multiple statistical parameters corresponding to different random matrices.

[0128] Any one or more of the modules, submodules, units, and subunits according to the embodiments of this application, or at least part of the functions of any one or more of them, can be implemented in one module. Any one or more of the modules, submodules, units, and subunits according to the embodiments of this application can be implemented by dividing them into multiple modules. Any one or more of the modules, submodules, units, and subunits according to the embodiments of this application can be at least partially implemented as hardware circuits, such as field-programmable gate arrays (FPGAs), programmable logic arrays (PLAs), systems-on-a-chip, systems-on-a-substrate, systems-on-package, application-specific integrated circuits (ASICs), or implemented by hardware or firmware in any other reasonable manner by integrating or packaging circuits, or implemented in any one of software, hardware, and firmware, or in a suitable combination of any of these. Alternatively, one or more of the modules, submodules, units, and subunits according to the embodiments of this application can be at least partially implemented as computer program modules, which, when run, can perform corresponding functions.

[0129] For example, any multiple of the following modules can be combined into one module / unit / subunit: first generation module 310, first generation module 410, fitting module 320, second generation module 420, solving module 330, third generation module 430, obtaining module 340, fourth generation module 440, measurement module 350, and estimation module 360. Alternatively, any one of these modules / units / subunits can be split into multiple modules / units / subunits. Or, at least some of the functionality of one or more of these modules / units / subunits can be combined with at least some of the functionality of other modules / units / subunits and implemented in one module / unit / subunit. According to embodiments of this application, at least one of the following modules—first generation module 310, first generation module 410, fitting module 320, second generation module 420, solving module 330, third generation module 430, obtaining module 340, fourth generation module 440, measurement module 350, and estimation module 360—can be at least partially implemented as hardware circuits, such as field-programmable gate arrays (FPGAs), programmable logic arrays (PLAs), systems-on-a-chip, systems-on-a-substrate, systems-on-package, application-specific integrated circuits (ASICs), or any other reasonable method of integrating or packaging circuits, or implemented in software, hardware, or firmware, or in any appropriate combination of any of these three methods. Alternatively, at least one of the following modules—first generation module 310, first generation module 410, fitting module 320, second generation module 420, solving module 330, third generation module 430, obtaining module 340, fourth generation module 440, measurement module 350, and estimation module 360—can be at least partially implemented as a computer program module, which, when run, can perform corresponding functions.

[0130] It should be noted that the quantum state property analysis device part in the embodiments of this application corresponds to the quantum state property analysis method part in the embodiments of this application. The description of the quantum state property analysis device part is specifically referred to in the quantum state property analysis method part, and will not be repeated here.

[0131] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation that may be implemented by the apparatus and methods according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions. Those skilled in the art will understand that the features recited in the various embodiments and / or claims of this application can be combined and / or combined in various ways, even if such combinations or combinations are not expressly stated in this application. In particular, the various embodiments and / or features described in the claims of this application may be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application.

[0132] The embodiments of this application have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of this application. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this application is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this application, and all such substitutions and modifications should fall within the scope of this application.

Claims

1. A method for analyzing the properties of quantum states in a distributed scenario, characterized in that, include: For any quantum terminal, a block-encoded unitary matrix is ​​generated according to a preset purification operator, wherein there is no quantum communication behavior between different quantum terminals; The objective function is fitted to obtain a polynomial function; The polynomial function is solved using the Remez algorithm to obtain a phase tuple, wherein the phase tuple includes multiple phase elements; A control gate is applied to a singular value transform circuit to obtain a control block coding operator, wherein the singular value transform circuit is obtained based on the number of phase elements and the block coding unitary matrix; Based on the iterative application of the control block encoding operator to a preset quantum state for measurement, multiple measurement results are obtained, including: Two random matrices are randomly selected from the preset Haar random matrix for each quantum terminal; For the j-th iteration of any quantum terminal, a target state is generated when the control block encoding operator acts on a preset initial state and the Hadamard gate acts on the first qubit of the preset initial state, wherein the preset initial state is generated based on two random matrices of the quantum terminal; and The target state is measured on the Z basis to obtain multiple measurement results corresponding to the j-th iteration, wherein each measurement result corresponds to a random matrix; Based on multiple measurement results from different quantum terminals, unbiased estimation information for the distributed scenario is generated, including: For each quantum terminal, a dataset corresponding to each random matrix is ​​generated based on the multiple measurement results corresponding to the quantum terminal; For each of the random matrices, statistical parameters corresponding to the random matrix are generated based on the dataset corresponding to the random matrix and the dimension of the density operator corresponding to the preset purification operator; and The unbiased estimation information is generated based on multiple statistical parameters corresponding to different random matrices; The fidelity and / or relative entropy of the quantum states between different quantum terminals are calculated based on the unbiased estimation information.

2. The method according to claim 1, characterized in that, Applying control gates to singular value transform circuits to obtain control block encoding operators includes: The control gates are applied to each initial gate in the singular value transform circuit to obtain the control block encoding operator.

3. The method according to claim 2, characterized in that, The singular value transformation circuit is generated in the following manner: When the number is odd, a first singular value transform circuit is generated based on the number of phase elements and the block-coded unitary matrix. When the number is even, a second singular value transformation circuit is generated based on the number of phase elements and the block-coded unitary matrix, wherein the singular value transformation circuit includes either the first singular value transformation circuit or the second singular value transformation circuit.

4. The method according to claim 1, characterized in that, Two random matrices are randomly selected from the preset Haar random matrix for each quantum terminal, including: For each quantum terminal, a first matrix is ​​randomly selected from the preset Haar random matrix. For each quantum terminal, a different second matrix is ​​randomly selected from the preset Haar random matrix.

5. A quantum state property analysis device in a distributed scenario, characterized in that, include: The first generation module is used to generate a block-encoded unitary matrix for any quantum terminal according to a preset purification operator, wherein there is no quantum communication behavior between different quantum terminals; The fitting module is used to perform function fitting on the objective function to obtain a polynomial function. The solution module is used to solve the polynomial function using the Remez algorithm to obtain a phase tuple, wherein the phase tuple includes multiple phase elements; A module is obtained for applying a control gate to a singular value transform circuit to obtain a control block coding operator, wherein the singular value transform circuit is obtained based on the number of phase elements and the block coding unitary matrix; The measurement module is used to iteratively apply the control block encoding operator to a preset quantum state to perform measurements and obtain multiple measurement results; An estimation module is used to generate unbiased estimation information for the distributed scenario based on multiple measurement results from different quantum terminals; and The computation module is used to calculate the fidelity and / or relative entropy of quantum states between different quantum terminals based on unbiased estimation information; The measurement module includes: The random unit is used to randomly select two random matrices from the preset Haar random matrix for each quantum terminal; The fifth generation unit is used to generate the target state for the j-th iteration of any quantum terminal, given that the control block encoding operator operates on a preset initial state and the Hadamard gate operates on the first qubit of the preset initial state. The preset initial state is generated based on two random matrices of the quantum terminal. The sixth generation unit is used to measure the target state on the Z basis and obtain multiple measurement results corresponding to the j-th iteration, where each measurement result corresponds to a random matrix; The estimation module includes: The seventh generation unit is used to generate a dataset corresponding to each random matrix for each quantum terminal based on multiple measurement results corresponding to the quantum terminal. The eighth generation unit is used to generate statistical parameters for each random matrix based on the dataset corresponding to the random matrix and the dimension of the density operator corresponding to the preset purification operator; and The ninth generation unit is used to generate unbiased estimation information based on multiple statistical parameters corresponding to different random matrices.

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