CN115719098B - Bell measuring equipment verification method and device, electronic equipment and medium - Google Patents

Abstract

The present disclosure provides a Bell measurement device verification method, apparatus, electronic device, computer-readable storage medium and computer program product, which relate to the computer field, and in particular to the quantum computer technology field. The implementation scheme is: determining a set of detection quantum states, wherein the detection quantum states in the detection quantum state set correspond one-to-one to the corresponding post-processing operators, and the post-processing operators are determined based on all measurement results that can be obtained by measuring the corresponding detection quantum states by an ideal Bell measurement device; repeating the following operations multiple times: randomly selecting a detection quantum state in the detection quantum state set to measure the detection quantum state through the Bell measurement device to be verified to obtain a measurement result; and in response to determining that the measurement results obtained by each operation appear in the corresponding post-processing operator, determining that the Bell measurement device to be verified is verified.

Description

Bell measurement equipment verification method and device, electronic equipment and medium

Technical Field

The present disclosure relates to the field of computers, in particular to the field of quantum computer technology, and specifically to a Bell measurement device verification method, device, electronic device, computer-readable storage medium, and computer program product.

Background technique

As more and more emerging quantum technologies continue to emerge, quantum hardware technology is also improving year by year, and quantum communication and quantum Internet are also developing continuously. One of the important resources of quantum technology is Bell Measurement, which is the core resource and basic component of quantum computing and quantum information processing. It is the core part of many famous quantum information processing cases such as Quantum Key Distribution, Quantum Superdense Coding, Quantum Teleportation, etc. Therefore, verifying whether an unknown quantum measurement device can accurately achieve Bell measurement is the core problem of quantum computing.

Summary of the invention

The present disclosure provides a Bell measurement device verification method, apparatus, electronic device, computer-readable storage medium, and computer program product.

According to one aspect of the present disclosure, a Bell measurement device verification method is provided, including: determining a set of detection quantum states, wherein the detection quantum states in the detection quantum state set correspond one-to-one to corresponding post-processing operators, wherein the post-processing operators are determined based on all measurement results that can be obtained by measuring the corresponding detection quantum states with an ideal Bell measurement device; repeating the following operations multiple times: randomly selecting a detection quantum state from the detection quantum state set to measure the detection quantum state with a Bell measurement device to be verified to obtain a measurement result; and in response to determining that the measurement results obtained by each operation appear in the corresponding post-processing operator, determining that the Bell measurement device to be verified is verified.

According to another aspect of the present disclosure, a Bell measurement device verification apparatus is provided, comprising: a first determination unit, configured to determine a set of detection quantum states, wherein the detection quantum states in the detection quantum state set correspond one-to-one to corresponding post-processing operators, wherein the post-processing operators are determined based on all measurement results that can be obtained by measuring the corresponding detection quantum states with an ideal Bell measurement device; an operation unit, configured to repeatedly perform the following operations multiple times: randomly select a detection quantum state from the detection quantum state set to measure the detection quantum state with a Bell measurement device to be verified to obtain a measurement result; and a verification unit, configured to determine that the Bell measurement device to be verified has been verified in response to determining that the measurement results obtained by each operation appear in the corresponding post-processing operator.

According to another aspect of the present disclosure, an electronic device is provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the method described in the present disclosure.

According to another aspect of the present disclosure, a non-transitory computer-readable storage medium storing computer instructions is provided. The computer instructions are used to cause a computer to execute the method described in the present disclosure.

According to another aspect of the present disclosure, a computer program product is provided, including a computer program, which implements the method described in the present disclosure when executed by a processor.

According to one or more embodiments of the present disclosure, the verification task can be completed using only local quantum operations and classical communications, and it is ensured that when the unknown measuring device does not implement Bell measurement, the probability of erroneously asserting that the verification has passed is small.

It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings exemplarily illustrate the embodiments and constitute a part of the specification, and together with the text description of the specification, are used to explain the exemplary implementation of the embodiments. The embodiments shown are for illustrative purposes only and do not limit the scope of the claims. In all drawings, the same reference numerals refer to similar but not necessarily identical elements.

FIG1 shows a flow chart of a Bell measurement device verification method according to an embodiment of the present disclosure;

FIG2 is a schematic diagram showing a Bell measurement device verification method according to an embodiment of the present disclosure;

FIG3 shows a structural block diagram of a Bell measurement device verification apparatus according to an embodiment of the present disclosure; and

FIG. 4 shows a block diagram of an exemplary electronic device that can be used to implement the embodiments of the present disclosure.

Detailed ways

The following is a description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, including various details of the embodiments of the present disclosure to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope of the present disclosure. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

In the present disclosure, unless otherwise specified, the use of the terms "first", "second", etc. to describe various elements is not intended to limit the positional relationship, timing relationship, or importance relationship of these elements, and such terms are only used to distinguish one element from another element. In some examples, the first element and the second element may refer to the same instance of the element, and in some cases, based on the description of the context, they may also refer to different instances.

The terms used in the description of various examples in this disclosure are only for the purpose of describing specific examples and are not intended to be limiting. Unless the context clearly indicates otherwise, if the number of elements is not specifically limited, the element can be one or more. In addition, the term "and/or" used in this disclosure covers any one of the listed items and all possible combinations.

The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

So far, all the different types of computers in use are based on classical physics as the theoretical basis for information processing, and are called traditional computers or classical computers. Classical information systems use binary data bits, which are the easiest to implement physically, to store data or programs. Each binary data bit is represented by 0 or 1, called a bit or bit, as the smallest unit of information. Classical computers themselves have inevitable weaknesses: one is the most basic limitation of energy consumption in the computing process. The minimum energy required for logic elements or storage units should be several times more than kT to avoid misoperation due to thermal expansion and fall; the second is information entropy and heat energy consumption; the third is that when the wiring density of computer chips is very high, according to the Heisenberg uncertainty relation, when the uncertainty of the electron position is very small, the uncertainty of the momentum will be very large. Electrons are no longer bound, and there will be quantum interference effects, which may even destroy the performance of the chip.

A quantum computer is a type of physical device that follows the properties and laws of quantum mechanics to perform high-speed mathematical and logical operations, store and process quantum information. When a device processes and calculates quantum information and runs quantum algorithms, it is a quantum computer. Quantum computers follow the unique laws of quantum dynamics (especially quantum interference) to achieve a new mode of information processing. For parallel processing of computational problems, quantum computers have an absolute advantage in speed over classical computers. The transformation of each superposition component by a quantum computer is equivalent to a classical calculation. All these classical calculations are completed at the same time and superimposed according to a certain probability amplitude to give the output result of the quantum computer. This calculation is called quantum parallel computing. Quantum parallel processing greatly improves the efficiency of quantum computers, allowing them to complete tasks that classical computers cannot complete, such as factoring a large natural number. Quantum coherence is essentially used in all quantum ultra-fast algorithms. Therefore, quantum parallel computing, which replaces classical states with quantum states, can achieve computing speeds and information processing functions that are incomparable to classical computers, while saving a lot of computing resources.

Taking the quantum super-dense coding protocol as an example, the quantum protocol is as follows: Alice and Bob, the two parties to the protocol, pre-share a pair of highly entangled Bell states; Alice performs corresponding quantum coding operations on the quantum bits she holds according to the two bits of classical information that need to be transmitted, and then transmits the quantum bit after the operation to Bob through the quantum channel; Bob performs Bell measurement on the received quantum bits and the quantum bits originally held to decode the two bits of classical information transmitted by Alice. The quantum super-dense coding protocol cleverly utilizes the properties of quantum entanglement to achieve the transmission of two classical bits of information through one quantum bit, thereby realizing a communication method with greater capacity and higher efficiency.

It can be seen that Bob needs to perform precise Bell measurements to fully decode the two bits of classical information transmitted by Alice. If the Bell measurements he performs are not precise enough, the super-cryptographic coding protocol will not work properly, Bob will not be able to accurately decode the classical information transmitted by Alice, and the advantages of quantum information processing will not be realized. In fact, the experimental implementation of Bell measurements is relatively difficult.

As can be seen from the quantum super-dense coding protocol above, how to verify whether an unknown measuring device accurately implements Bell measurement is a core problem of quantum computing. In theory, the local verification problem of Bell measurement can be solved using quantum detector tomography technology. This method constructs different quantum input states, uses a given unknown device for measurement, and counts the measurement results. Then, data post-processing is performed to obtain the complete information of the unknown measuring device. Once the complete information of the unknown device is known, it is natural to determine whether the unknown device has implemented Bell measurement.

However, there are two problems with using quantum detector tomography to solve the problem of local verification of Bell measurement: First, although tomography can depict the complete information of the measurement device, the cost of tomography is very high. Under the existing technical conditions, the quantum state resources that need to be prepared are ,in is the number of quantum bits of the measuring device. In addition, a classical computer is needed for data post-processing in tomography. The current best method for calculating the inverse matrix has a complexity of , which makes the tomography method inefficient and limited. Secondly, for the local verification problem of Bell measurement, it is only necessary to verify whether a given unknown device can achieve Bell measurement, without knowing the complete information of the unknown device. In other words, the tomography technology provides redundant information, and redundant information means unnecessary resource consumption.

Therefore, according to an embodiment of the present disclosure, a Bell measurement device verification method is provided. FIG. 1 shows a flowchart of a Bell measurement device verification method according to an embodiment of the present disclosure. As shown in FIG. 1 , method 100 includes: determining a set of detection quantum states, wherein the detection quantum states in the detection quantum state set correspond one-to-one to corresponding post-processing operators, wherein the post-processing operator is determined based on all measurement results that can be obtained by measuring the corresponding detection quantum states by an ideal Bell measurement device (step 110); repeating the following operations multiple times: randomly selecting a detection quantum state from the detection quantum state set to measure the detection quantum state through a Bell measurement device to be verified to obtain a measurement result (step 120); and in response to determining that the measurement results obtained by each operation appear in the corresponding post-processing operator, determining that the Bell measurement device to be verified is verified (step 130).

According to the embodiments of the present disclosure, the verification task can be completed using only local quantum operations and classical communications, and it is ensured that when the unknown measuring device does not implement Bell measurement, the probability of erroneously asserting that the verification has passed is small.

It can be understood that there are four Bell States for two qubits, defined as follows:

in, and They represent the Pauli X operator and the Pauli Z operator respectively. Bell measurement is a measurement of two quantum bits, and its four measurement operators correspond to the four Bell states mentioned above. Bell measurement is simply written as: ,in , The subscript i in the number represents the corresponding output result. That is, there are four output results of Bell measurement, namely 0, 1, 2, and 3, which are expressed in binary as 00, 01, 10, and 11.

In some examples, given an unknown two-qubit measurement device , the measurement fidelity can be defined as follows to characterize its difference from Bell measurement Similarity:

This fidelity describes to some extent and In particular, if ,That It must be a Bell measurement.

If a device manufacturer (called an Adversary) builds a two-qubit unknown measurement device , it can be verified that the measuring device must belong to one of the following two situations: the measuring device accurately realizes Bell measurement, that is, , that is, the verification is passed; or, the fidelity of the measurement and Bell measurement achieved by the measuring equipment is less than or equal to ,Right now ,in It is the error value preset by the equipment manufacturer, that is, the verification failed, as shown in Figure 2.

In some examples, considering that the verification process itself cannot consume more or more stringent resources than the object to be verified (Bell measurement), it is generally required that the two parties involved in the verification can only use local quantum operations (Local Quantum Operation) and classical communication (Classical Communication) to complete the verification process through classical data post-processing. Therefore, in some embodiments, in order to determine as accurately as possible whether the unknown device implements Bell measurement, the local verification strategy for verifying the unknown measurement device must meet the following constraints: If the unknown measurement device implements Bell measurement, it can always be asserted that the verification is passed, that is, to prevent qualified products from being asserted as unqualified products; if the unknown measurement device does not implement Bell measurement, the probability of erroneously asserting that the verification is passed is as small as possible.

At present, it is difficult to prepare entangled detection states, especially Bell states, that is, the global verification strategy is difficult to implement. Therefore, in some embodiments, the input detection state can be constrained to be a local state, that is, the verifiers Alice and Bob each prepare quantum states without using any entanglement. In addition, in some embodiments, the verifier can be constrained to prepare random detection states. If the detection state is not random, the device manufacturer may customize a non-Bell measurement device that can always pass the test based on the detection state information prepared by the verifier, thereby deceiving the verifier.

According to some embodiments, the set of probe quantum states may be determined based on an eigenvector corresponding to at least one of the following: a Pauli X operator, a Pauli Y operator, and a Pauli Z operator.

Specifically, before verifying the Bell measurement device, the following quantum state representation can be introduced:

in, is the eigenvector of the Pauli Z operator, , is the eigenvector of the Pauli X operator, and , is the eigenvector of the Pauli Y operator. Based on the above quantum state, a corresponding set of detection quantum states and its corresponding post-processing operator can be constructed to verify the Bell measurement device based on the set of detection quantum states.

To verify the Bell measurement, one can construct a probe quantum state containing many different types of A set of detected quantum states, each of which has a corresponding post-processing operator . Post-processing operators This involves measuring the input quantum state through an ideal Bell measurement device. All possible measurement results that can be obtained by measuring, that is, summarizing these possible measurement results to obtain the corresponding post-processing operator For example, if the detection state , then the possible measurement results are 00, 01 (measurement results are represented in binary), so the corresponding post-processing operator for: This construction probes the set of quantum states and their corresponding post-processing operators This approach ensures that if the unknown measuring device being verified actually implements the Bell measurement, it will always pass the verification test.

It is understandable that the number and type of detection quantum states in the detection quantum state set can be arbitrary, but different numbers and types of detection quantum state sets may affect the cost required to verify the Bell measurement device (such as the number of times the verification operation is performed).

According to some embodiments, the method according to the present disclosure may further include: determining a preset error value and a preset confidence level of the Bell measurement device to be verified; and determining the number of times to repeat the operation based on the error value and the confidence level.

It is understandable that the more repetitions there are, the more accurate the verification result is. When the number of executions is determined based on the allowable measurement error and the acceptable confidence level for erroneous judgments, the waste of computational effort caused by repeated verification operations can be avoided while ensuring accuracy requirements.

In some embodiments, after obtaining the set of detection quantum states, the detection performance of the set can be further determined, that is, the ability of the set of detection quantum states to detect Bell measurements. Specifically, the quantum detection operator corresponding to the set of detection quantum states can be constructed according to the following formula: :

in, is the number of qubits in the system, and represents the number of the detected quantum states in the set Detection quantum state The transposed matrix of is the number of detection quantum states in the detection quantum state set, To detect the first indivual The probability of being selected. When a random selection is made, Intuitively, the quantum detection operator , that is, the combination of each probe quantum state in the set and the post-processing operator After transposition and tensor operations, the sum is accumulated according to the probability distribution. It can be theoretically proved that the quantum detection operator The second largest eigenvalue of It can be used to fully characterize the performance of the set of detected quantum states. After the eigenvalues of are sorted from large to small, the second eigenvalue is the second largest eigenvalue. Therefore, the number of times the operation is repeatedly performed can be determined based on the second largest eigenvalue of the quantum detection operator corresponding to the detection quantum state set.

According to some embodiments, the number of times to repeat the operation may be determined based on the following formula: :

in, is the second largest eigenvalue of the quantum detection operator corresponding to the set of detection quantum states, is the error value, is the confidence level. Error value Characterize the performance and confidence of the measurement equipment they manufacture Represents the confidence level in accepting an incorrect judgment.

It can be proved that the second largest eigenvalue corresponding to the global optimal verification scheme (the global optimal scheme is to prepare Bell states as detection states) is 0. According to the above formula, it can be proved that the minimum number of detection quantum states required to be prepared for the local verification scheme is:

By comparison, the additional cost coefficient of the local verification scheme relative to the global optimal verification scheme can be as low as 3/2. Among them, Table 1 gives the form of a detection quantum state set corresponding to the minimum additional cost coefficient and its corresponding post-processing operator. It can be understood that although the detection quantum state set given in Table 1 is optimal (that is, the number of detection quantum states required to be prepared by the verification scheme is the least), it does not mean that the set is unique. Other detection quantum state sets can be constructed, as long as the second largest eigenvalue of the corresponding quantum detection operator Ω is 1/3, then the detection quantum state set is also optimal.

Table 1

In one embodiment according to the present disclosure, an unknown Bell measurement device is determined ,difference (This value can be given by the equipment manufacturer to characterize the performance of the measurement equipment it manufactures), confidence (This value is pre-selected by the verifier and records the confidence level for accepting an incorrect judgment.) Then the following operation flow is performed:

Step 1: Calculate the total number of test rounds to be performed based on the selected set of probe quantum states , and initialize the iteration parameters .

Step 2: Update iteration parameters , and make the following judgment: If , jump to step 5 (verification process ends, all detection states pass the test); if , execute the third step (obtain a new detection state and continue testing the unknown Bell measurement device).

Step 3: Based on the selected set of detection quantum states, according to the probability distribution (the probability of each detection state being selected is 1/ ) Randomly select the probe quantum state And record the corresponding post-processing operator (Subscript Indicates wheel is selected). Using the measuring device Pair detection state Take measurements and record the results ,in ∈{00, 01, 10, 11}, is a two-bit string.

Step 4: and the corresponding post-processing operator For comparison: If Appears in postprocessing operators , jump to step 2; if Does not appear in postprocessing operators If it is not verified, it will directly output: Not verified.

Step 5: Output verification passed.

It is understandable that the output result of the above scheme should be understood as follows: if the output result is not verified, then the verified unknown measurement device must not be Bell measurement; if the output result is verified, then the verified unknown measurement device has more than The probability is a Bell measure.

According to an embodiment of the present disclosure, as shown in FIG3 , a Bell measurement device verification apparatus 300 is also provided, including: a first determination unit 310, configured to determine a set of detection quantum states, wherein the detection quantum states in the detection quantum state set correspond one-to-one to corresponding post-processing operators, wherein the post-processing operators are determined based on all measurement results that can be obtained by measuring the corresponding detection quantum states with an ideal Bell measurement device; an operation unit 320, configured to repeatedly perform the following operations multiple times: randomly select a detection quantum state from the detection quantum state set to measure the detection quantum state with a Bell measurement device to be verified to obtain a measurement result; and a verification unit 330, configured to determine that the Bell measurement device to be verified has been verified in response to determining that the measurement results obtained by each operation appear in the corresponding post-processing operator.

Here, the operations of the above-mentioned units 310-330 of the Bell measurement equipment verification device 300 are similar to the operations of the steps 110-130 described above, and will not be repeated here.

According to an embodiment of the present disclosure, an electronic device, a readable storage medium and a computer program product are also provided.

With reference to Figure 4, the structural block diagram of an electronic device 400 that can be used as a server or client of the present disclosure will now be described, which is an example of a hardware device that can be applied to various aspects of the present disclosure. The electronic device is intended to represent various forms of digital electronic computer equipment, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples, and are not intended to limit the implementation of the present disclosure described and/or required herein.

As shown in FIG4 , the electronic device 400 includes a computing unit 401, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 402 or a computer program loaded from a storage unit 408 into a random access memory (RAM) 403. In the RAM 403, various programs and data required for the operation of the electronic device 400 can also be stored. The computing unit 401, the ROM 402, and the RAM 403 are connected to each other via a bus 404. An input/output (I/O) interface 405 is also connected to the bus 404.

Multiple components in the electronic device 400 are connected to the I/O interface 405, including: an input unit 406, an output unit 407, a storage unit 408, and a communication unit 409. The input unit 406 can be any type of device that can input information to the electronic device 400. The input unit 406 can receive input digital or character information and generate key signal input related to user settings and/or function control of the electronic device, and can include but is not limited to a mouse, a keyboard, a touch screen, a track pad, a track ball, a joystick, a microphone, and/or a remote controller. The output unit 407 can be any type of device that can present information, and can include but is not limited to a display, a speaker, a video/audio output terminal, a vibrator, and/or a printer. The storage unit 408 can include but is not limited to a disk, an optical disk. The communication unit 409 allows the electronic device 400 to exchange information/data with other devices through a computer network such as the Internet and/or various telecommunication networks, and can include but is not limited to a modem, a network card, an infrared communication device, a wireless communication transceiver, and/or a chipset, such as a Bluetooth™ device, an 802.11 device, a WiFi device, a WiMax device, a cellular communication device, and/or the like.

The computing unit 401 may be a variety of general and/or special processing components with processing and computing capabilities. Some examples of the computing unit 401 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 401 performs the various methods and processes described above, such as method 100. For example, in some embodiments, the method 100 may be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit 408. In some embodiments, part or all of the computer program may be loaded and/or installed on the electronic device 400 via the ROM 402 and/or the communication unit 409. When the computer program is loaded into the RAM 403 and executed by the computing unit 401, one or more steps of the method 100 described above may be performed. Alternatively, in other embodiments, the computing unit 401 may be configured to perform the method 100 in any other appropriate manner (e.g., by means of firmware).

Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and/or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and/or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

The program code for implementing the method of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, implements the functions/operations specified in the flow chart and/or block diagram. The program code may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

In the context of the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer 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 of the foregoing.

To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), the Internet, and a blockchain network.

A computer system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship with each other. The server may be a cloud server, a server of a distributed system, or a server combined with a blockchain.

It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in this disclosure can be performed in parallel, sequentially or in a different order, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document is not limited here.

Although the embodiments or examples of the present disclosure have been described with reference to the accompanying drawings, it should be understood that the above-mentioned methods, systems and devices are merely exemplary embodiments or examples, and the scope of the present invention is not limited by these embodiments or examples, but is only limited by the claims after authorization and their equivalents. Various elements in the embodiments or examples may be omitted or replaced by their equivalents. In addition, each step may be performed in an order different from that described in the present disclosure. Further, the various elements in the embodiments or examples may be combined in various ways. It is important that with the evolution of technology, many of the elements described herein may be replaced by equivalent elements that appear after the present disclosure.

Claims (15)

1. A bell measurement device verification method, comprising:

Determining a set of detection quantum states, wherein the detection quantum states in the set of detection quantum states are in one-to-one correspondence with corresponding post-processing operators, and the post-processing operators are determined based on all measurement results obtained by measuring the corresponding detection quantum states by ideal bell measurement equipment;

The following operations are repeatedly performed a plurality of times: randomly selecting one detection quantum state from the detection quantum state set, so as to measure the detection quantum state through Bell measuring equipment to be verified, and obtaining a measurement result; and

In response to determining that the measurement result obtained for each operation appears in the corresponding post-processing operator, it is determined that the bell measurement device to be verified is verified.

2. The method of claim 1, further comprising:

Determining a preset error value and a preset confidence coefficient of the Bell measuring equipment to be verified; and

And determining the number of times of repeatedly executing the operation based on the error value and the confidence.

3. The method of claim 1 or 2, wherein the number of times the operation is repeatedly performed is determined based on a second largest eigenvalue of a quantum detection operator corresponding to the set of detected quantum states, wherein the quantum detection operatorThe determination is based on the following formula:

Wherein, For the number of qubits of the Bell measuring device to be verifiedRepresenting the first of the set of detected quantum statesEach detection quantum stateIs used to determine the transposed matrix of (a),For the number of detected quantum states in the set of detected quantum states,For a detected quantum state in the set of detected quantum statesThe corresponding probability of the probability of being high,Is the firstEach detection quantum stateThe corresponding post-processing operators are used to determine,Representing tensor operations.

4. The method of claim 3, wherein the number of times the operation is repeatedly performed is determined based on the following formula：

Wherein,For the second largest eigenvalue of the quantum detection operator,Is the error value of the preset Bell measuring equipment to be verified,And the confidence level of the Bell measuring equipment to be verified is preset.

5. The method of claim 1, wherein the set of detection quantum states is determined based on feature vectors corresponding to at least one of: a Brix operator, a Brix Y operator, and a Brix Z operator.

6. The method of claim 5, wherein the set of detected quantum states is determined based on at least one of the following quantum states:、、、、、、、、、、、 Wherein, the method comprises the steps of, wherein, AndA feature vector representing the brix Z operator,AndA feature vector representing the berlite X operator,AndA feature vector representing the berlite Y operator.

7. A bell measurement device verification apparatus comprising:

The first determining unit is configured to determine a set of detection quantum states, wherein the detection quantum states in the set of detection quantum states are in one-to-one correspondence with corresponding post-processing operators, and the post-processing operators are determined based on all measurement results obtained by measuring the corresponding detection quantum states by ideal bell measuring equipment;

An operation unit configured to repeatedly perform the following operations a plurality of times: randomly selecting one detection quantum state from the detection quantum state set, so as to measure the detection quantum state through Bell measuring equipment to be verified, and obtaining a measurement result; and

And a verification unit configured to determine that the bell measurement device to be verified is verified in response to determining that the measurement result obtained by each operation appears in the corresponding post-processing operator.

8. The apparatus of claim 7, further comprising:

A second determining unit configured to determine a preset error value and a preset confidence level of the bell measuring device to be verified; and

And a third determination unit configured to determine the number of times the operation is repeatedly performed based on the error value and the confidence.

9. The apparatus of claim 7 or 8, wherein the number of times the operation is repeatedly performed is determined based on a second largest eigenvalue of a quantum detection operator corresponding to the set of detected quantum states, wherein the quantum detection operatorThe determination is based on the following formula:

Wherein, For the number of qubits of the Bell measuring device to be verifiedRepresenting the first of the set of detected quantum statesEach detection quantum stateIs used to determine the transposed matrix of (a),For the number of detected quantum states in the set of detected quantum states,For a detected quantum state in the set of detected quantum statesThe corresponding probability of the probability of being high,Is the firstEach detection quantum stateThe corresponding post-processing operators are used to determine,Representing tensor operations.

10. The apparatus of claim 9, wherein the number of times the operation is repeatedly performed is determined based on the following formula：

Wherein,For the second largest eigenvalue of the quantum detection operator,Is the error value of the preset Bell measuring equipment to be verified,And the confidence level of the Bell measuring equipment to be verified is preset.

11. The apparatus of claim 7, wherein the set of detection quantum states is determined based on feature vectors corresponding to at least one of: a Brix operator, a Brix Y operator, and a Brix Z operator.

12. The apparatus of claim 11, wherein the set of detected quantum states is determined based on at least one of the following quantum states:、、、、、、、、、、、 Wherein, the method comprises the steps of, wherein, AndA feature vector representing the brix Z operator,AndA feature vector representing the berlite X operator,AndA feature vector representing the berlite Y operator.

13. An electronic device, comprising:

At least one processor; and

A memory communicatively coupled to the at least one processor; wherein the method comprises the steps of

The memory stores instructions executable by the at least one processor to enable the at least one processor to perform the method of any one of claims 1-6.

14. A non-transitory computer readable storage medium storing computer instructions for causing the computer to perform the method of any one of claims 1-6.

15. A computer program product comprising a computer program, wherein the computer program, when executed by a processor, implements the method of any of claims 1-6.