CN112529196B

CN112529196B - Quantum entanglement detection method and device, electronic device and storage medium

Info

Publication number: CN112529196B
Application number: CN202011457298.0A
Authority: CN
Inventors: 王鑫; 王琨; 宋旨欣
Original assignee: Beijing Baidu Netcom Science and Technology Co Ltd
Current assignee: Beijing Baidu Netcom Science and Technology Co Ltd
Priority date: 2020-12-10
Filing date: 2020-12-10
Publication date: 2021-11-23
Anticipated expiration: 2040-12-10
Also published as: CN112529196A

Abstract

The application discloses a quantum entanglement detection method and device, electronic equipment and a storage medium, and relates to the technical field of quantum computing. The specific implementation scheme is as follows: obtaining parameterized quantum circuits and respectively acting the parameterized quantum circuits on four initial quantum states to obtain four first quantum states, wherein the parameterized quantum circuits comprise adjustable parameters; respectively constructing four quantum gates, and respectively acting the four quantum gates on the quantum state to be measured to obtain four second quantum states; obtaining a loss function based on the four first quantum states and the four second quantum states; minimizing the loss function and obtaining the value of the loss function after minimization; and detecting whether the quantum state to be detected is an entangled state or not based on the value. The scheme provided by the application reduces the workload of quantum entanglement detection.

Description

Quantum entanglement detection method and device, electronic device and storage medium

Technical Field

The present disclosure relates to the field of quantum computing technologies, and in particular, to a quantum entanglement detection method, a quantum entanglement detection device, an electronic apparatus, and a storage medium.

Background

In the technical field of quantum computing, quantum entanglement is a key resource for realizing various quantum information technologies such as quantum encryption, quantum computing and quantum networks, and stable and reliable quantum entanglement detection can identify or verify the quantum entanglement resource more easily in quantum entanglement processing. At present, the quantum entanglement detection mode is more complex, such as two-square quantum state rho of n quantum bit_ABApproximately 2 copies are requiredⁿP is_ABAchievement 2ⁿA different detection scheme.

Disclosure of Invention

The application provides a quantum entanglement detection method, a quantum entanglement detection device, electronic equipment and a storage medium.

According to an aspect of the present application, there is provided a quantum entanglement detection method including:

obtaining parameterized quantum circuits and respectively acting the parameterized quantum circuits on four initial quantum states to obtain four first quantum states, wherein the parameterized quantum circuits comprise adjustable parameters;

respectively constructing four quantum gates, and respectively acting the four quantum gates on the quantum state to be measured to obtain four second quantum states;

obtaining a loss function based on the four first quantum states and the four second quantum states;

minimizing the loss function and obtaining the value of the loss function after minimization;

and detecting whether the quantum state to be detected is an entangled state or not based on the value.

According to another aspect of the present application, there is provided a quantum entanglement detecting device including:

the first action module is used for acquiring a parameterized quantum circuit and respectively acting the parameterized quantum circuit on four initial quantum states to obtain four first quantum states, wherein the parameterized quantum circuit comprises adjustable parameters;

the second action module is used for respectively constructing four quantum gates and respectively acting the four quantum gates on the quantum state to be tested so as to obtain four second quantum states;

a first obtaining module, configured to obtain a loss function based on the four first quantum states and the four second quantum states;

the second acquisition module is used for minimizing the loss function and acquiring the value of the minimized loss function;

and the detection module is used for detecting whether the quantum state to be detected is an entangled state or not based on the value.

In a third aspect, the present application provides an electronic device, comprising:

at least one processor; and

a memory communicatively coupled to the at least one processor; wherein the content of the first and second substances,

the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the quantum entanglement detection method of one aspect described above.

In a fourth aspect, the present application provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to perform the quantum entanglement detection method described in the above-described aspect.

According to another aspect of the present application, there is provided a computer program product comprising a computer program which, when executed by a processor, implements the quantum entanglement detection method described in the above-mentioned aspect.

This application realizes the detection of quantum entanglement through constructing the quantum gate and combining parameterization quantum circuit, need not to consume a large amount of costs and goes to measure and obtain each matrix element in the density matrix of whole quantum state, has reduced the work load that quantum entanglement detected, has promoted the efficiency that quantum entanglement detected.

Other effects of the above-described alternative will be described below with reference to specific embodiments.

Drawings

The drawings are included to provide a better understanding of the present solution and are not intended to limit the present application. Wherein:

FIG. 1 is a flow chart of a quantum entanglement detection method provided herein;

FIG. 2 is a block diagram of a quantum entanglement detector as provided herein;

fig. 3 is a block diagram of an electronic device implementing a quantum entanglement detection method according to an embodiment of the present application.

Detailed Description

The following description of the exemplary embodiments of the present application, taken in conjunction with the accompanying drawings, includes various details of the embodiments of the application for the understanding of the same, which are to be considered exemplary only. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the present application. Also, descriptions of well-known functions and constructions are omitted in the following description for clarity and conciseness.

To date, the various types of computers in use are based on classical physics as the theoretical basis for information processing, called traditional computers or classical computers. Classical information systems store data or programs using the most physically realizable binary data bits, each represented by a 0 or 1, called a bit or bit, as the smallest unit of information. The classic computer itself has inevitable weaknesses: one is the most fundamental limitation of computing process energy consumption. The minimum energy required by the logic element or the storage unit is more than several times of kT so as to avoid the misoperation of thermal expansion and dropping; information entropy and heating energy consumption; thirdly, when the wiring density of the computer chip is high, the uncertainty of the electronic position is small and the uncertainty of the momentum is large according to the heisenberg uncertainty relation. The electrons are no longer bound and there are quantum interference effects that can even destroy the performance of the chip.

Quantum computers (quantum computers) are physical devices that perform high-speed mathematical and logical operations, store and process quantum information in compliance with quantum mechanical properties and laws. When a device processes and calculates quantum information and runs a quantum algorithm, the device is a quantum computer. Quantum computers follow a unique quantum dynamics law, particularly quantum interference, to implement a new model of information processing. For parallel processing of computational problems, quantum computers have an absolute advantage in speed over classical computers. The transformation of each superposed component by the quantum computer is equivalent to a classical calculation, all the classical calculations are completed simultaneously and superposed according to a certain probability amplitude to give an output result of the quantum computer, and the calculation is called quantum parallel calculation. Quantum parallel processing greatly improves the efficiency of quantum computers, allowing them to accomplish tasks that classic computers cannot accomplish, such as factorization of a large natural number. Quantum coherence is essentially exploited in all quantum ultrafast algorithms. Therefore, quantum parallel computation of a classical state is replaced by a quantum state, so that the computation speed and the information processing function which are incomparable with a classical computer can be achieved, and meanwhile, a large amount of computation resources are saved.

With the rapid development of quantum computing technology, the application range of the quantum computing technology is wider and wider, and quantum communication and quantum internet are also continuously developed. One of the most important resources in quantum technology is quantum entanglement, which is an essential component of quantum computing and quantum information processing. Therefore, how to efficiently and stably detect quantum entanglement on recent quantum devices is a core problem in quantum technology. The application provides a quantum entanglement detection method and device and electronic equipment.

The following is an explanation of related concepts involved in the embodiments of the present application.

In practical applications of quantum communication, two-way quantum states (e.g., illustrated as A, B) are typically involved, where the quantum state includes a d_Ad_B×d_Ad_BMatrix of sizes ρ_ABThe matrix satisfies the following condition:

(1).ρ_ABis a Positive semidefinite term (Positive semidefinite term) denoted as ρ_AB≥0；

(2).ρ_ABThe sum of the diagonals of (a) is 1.

Before describing the technical solution of the embodiment of the present application, quantum states are defined as a Separable state (Separable state) and an Entangled state (Entangled states). If ρ_ABIn the isolated state, it can be represented by the following form:

wherein the content of the first and second substances,

and

are all quantum states, i.e., satisfy the above-mentioned condition (1) and condition (2) { p }₁,p₂,…,p_NIs a probability distribution that is,

the matrix Tensor product (Tensor product) operation is represented. If ρ_ABIf the formula is not satisfied, then ρ is considered_ABIs in an entangled state.

The embodiment of the application provides a quantum entanglement detection method for detecting quantum state(e.g.,. rho.)_AB) The method provided in the examples of the present application will be specifically described below as to whether the solution is in an entangled state or not.

Referring to fig. 1, fig. 1 is a flowchart illustrating a quantum entanglement detection method according to an embodiment of the present disclosure. As shown in fig. 1, the quantum entanglement detection method includes the following steps:

step S101, obtaining a parameterized quantum circuit, and respectively acting the parameterized quantum circuit on four initial quantum states to obtain four first quantum states, wherein the parameterized quantum circuit comprises adjustable parameters.

It should be noted that, an application scenario of the quantum entanglement detection method provided in the embodiment of the present application may be quantum state entanglement detection between two-level systems. Alternatively, the quantum entanglement detection method may be applied to electronic devices such as recent quantum devices, such as quantum computers and the like. In order to better describe the scheme provided by the embodiment of the present application, in the following description, the quantum entanglement detection method is applied to an electronic device for specific explanation.

In an embodiment of the application, an electronic device obtains a parameterized quantum circuit. Optionally, the parameterized quantum circuit is a parameterized quantum circuit with adjustable parameters, for example, the parameterized quantum circuit includes a plurality of single-qubit rotating gates and a controlled back-gate, where parameters of the plurality of single-qubit rotating gates form a vector, and the vector is an adjustable parameter of the parameterized quantum circuit. In some implementation scenarios, the parameterized quantum circuit may also be referred to as a quantum neural network.

Alternatively, the parameterized quantum circuit may be a parameterized quantum circuit that is determined by the electronic device based on user input, or that acquires user configuration. After acquiring the parameterized quantum circuit, the electronic device acts the parameterized circuit on the initial quantum state to obtain a new first quantum state. In some implementations, the initial quantum state may also be referred to as a probe quantum state.

For example, assume that the quantum state to be detected in the embodiments of the present application isρ_ABThat is, whether the two-level system A and the two-level system B are in an entangled state or not is detected; the electronic device can acquire four same initial quantum states |00 in advance based on input of a user>_ABAnd respectively acting the obtained parameterized quantum circuit U (theta) on the four initial quantum states |00>_ABThereby obtaining four identical first quantum states

Wherein the content of the first and second substances,

the operation represents the conjugate transpose, |00>Is a column unit vector, and<00 is a row unit vector.

And S102, respectively constructing four quantum gates, and respectively acting the four quantum gates on the quantum state to be measured to obtain four second quantum states.

Optionally, the four quantum gates may be four different quantum gates, and the quantum state to be detected is a quantum state to be detected in this embodiment, for example, ρ_AB. Respectively acting four different quantum gates on the quantum state to be measured; for example, the first quantum gate acts on the quantum state to be measured to obtain a second quantum state, and the second quantum gate acts on the quantum state to be measured to obtain a second quantum state … …, so that four different second quantum states can be obtained. It should be noted that the four quantum gates respectively act on the same side subsystem of the quantum state to be measured, so as to measure the quantum state rho_ABFor example, four quantum gates may be respectively applied to the two-level system a, or four quantum gates may be respectively applied to the two-level system B.

In one implementation of the embodiment of the present application, the four quantum gates are four specific quantum gates, or four predetermined quantum gates. An application scenario of the embodiment of the application may be a partial transposition Positive definite criterion (PPT criterion), and in the scenario, the four specific quantum gates are respectively a pauli matrix { X, Y, Z, I }, where

The application of these four specific quantum gates in the embodiments of the present application is specifically described in the following embodiments, and will not be described in detail herein.

Step S103, obtaining a loss function based on the four first quantum states and the four second quantum states.

In the embodiment of the present application, after obtaining four first quantum states and four second quantum states, a loss function is obtained based on the four first quantum states and the four second quantum states. For example, a trace function between a first quantum state and a second quantum state may be obtained, and then four trace functions may be obtained, and the loss function may be obtained based on the four trace functions. In some scenarios, the obtaining of the trace function between a first quantum state and a second quantum state may also be referred to as calculating an inner product between the first quantum state and the second quantum state, and then obtaining four inner products, and obtaining the loss function based on the four inner products.

In some embodiments, the step S103 may include;

respectively obtaining trace functions of a first quantum state and a second quantum state based on the four first quantum states and the four second quantum states to obtain four trace functions;

and obtaining a loss function based on the four trace functions.

It should be noted that the first quantum state is obtained by applying a parameterized quantum circuit to the initial quantum state, and the four initialized quantum states are the same, and the four obtained first quantum states are also the same; the second quantum state is obtained by respectively acting four different quantum gates on the quantum state to be measured, and the obtained four second quantum states are different. Alternatively, four same first quantum states may be paired with four different second quantum states one by one to obtain a trace function, that is, four different trace functions may be obtained, and the loss function may be obtained by the four trace functions. For example, the loss function may be a sum value between four trace functions. Therefore, the quantum gate is constructed to approximate the effect of the quantum state to be detected in the inner product scene, and the quantum state to be detected does not need to be subjected to chromatography to obtain the matrix form of the quantum state to be detected to detect whether the quantum state to be detected is entangled or not, so that the workload of entanglement detection of the quantum state to be detected is greatly reduced.

Optionally, the four trace functions include a first trace function, a second trace function, a third trace function, and a fourth trace function; the step of obtaining a loss function based on the four trace functions includes:

acquiring a target difference value of the first trace function and the second trace function;

obtaining a loss function based on a sum of the target difference and the third trace function and the fourth trace function.

Specifically, in the embodiment of the present application, four different quantum gates may be configured, which are respectively a first quantum gate, a second quantum gate, a third quantum gate, and a fourth quantum gate, and the four quantum gates are respectively applied to the quantum state to be measured to obtain four second quantum states.

For example, a first quantum gate is applied to the quantum state rho to be measured_ABTo obtain a second quantum state σ₁(ii) a Applying the second quantum gate to the quantum state rho to be measured_ABTo obtain a second quantum state σ₂(ii) a Applying the third quantum gate to the quantum state rho to be measured_ABTo obtain a third second quantum state σ₃(ii) a Applying the fourth quantum gate to the quantum state rho to be measured_ABTo obtain a fourth second quantum state σ₄. In this way, four different second quantum states can also be obtained.

Further, a trace function between one first quantum state and one second quantum state is obtained, and it can be understood that four first quantum states are the same, and further any one first quantum state and one second quantum state can be paired one by one to obtain a trace function. Alternatively, the trace function c may be obtained by using a Swap Test technique_j＝Tr(σ_jψ), where Tr (A) represents a trace of a matrix A, i.e., an element on a diagonal of the matrixThe sum of the elements. In the embodiment of the present application, a matrix is obtained based on a first quantum state and a second quantum state, and a trace function of the matrix is obtained. In some implementations, the obtaining a trace function between a first quantum state and a second quantum state may also be referred to as calculating an inner product between the first quantum state and the second quantum state.

For example, if the first quantum state is ψ, the four trace functions obtained in the embodiment of the present application are: c. C₁＝Tr(σ₁ψ)，c₂＝Tr(σ₂ψ)，c₃＝Tr(σ₃ψ)，c₄＝Tr(σ₄ψ)。

Further, a loss function is obtained based on the four trace functions, for example, the loss function L ═ C₁+C₂+C₃+C₄. Optionally, based on the four trace functions, the loss function may also have other calculation forms, which is not specifically listed in this embodiment.

In one implementation of the embodiments of the present application, the loss function L ═ C₁-C₂+C₃+C₄。

In the embodiment of the application, after four trace functions are obtained based on four first quantum states and four second quantum states, the loss functions are obtained through the four trace functions, so that the operation of the loss functions is simple and easy, a large amount of complex and tedious calculation is not needed, and further the entanglement detection of the quantum states to be detected is easier to realize and is easier to realize in workload.

And S104, minimizing the loss function, and acquiring the value of the minimized loss function.

In the embodiment of the application, after the loss function is obtained, the loss function is subjected to minimization processing to obtain a value of the loss function after minimization.

It is understood that the loss function is obtained based on a first quantum state and a second quantum state, and the first quantum state is obtained by acting a parameterized quantum circuit on an initial quantum state, the parameterized quantum circuit includes an adjustable parameter, and if the adjustable parameter is adjusted, the obtained first quantum state acting on the initial quantum state based on the parameterized quantum circuit is also adjusted accordingly, and further, the value obtained by the loss function is also adjusted accordingly. In the embodiment of the present application, the loss function may be minimized by adjusting the adjustable parameter.

Optionally, the step S104 may include:

and adjusting the adjustable parameters, and performing iterative processing on the loss function to minimize the loss function and obtain the value of the minimized loss function.

In some embodiments, a gradient descent method or other optimization method may be used to adjust the adjustable parameters, and the loss function is iteratively processed, that is, the above-mentioned process from step 101 to step 103 is repeated to minimize the loss function.

For example, the loss function is L ═ C₁-C₂+C₃+C₄If the adjustable parameter is 1, the loss function obtained by calculation is 0.5, and the adjustable parameter may be adjusted by using a gradient descent method, for example, if the adjustable parameter is adjusted to 0.5, an adjusted parameterized quantum circuit is obtained, and the above steps 101 to 103 are repeated to obtain a loss function of 0.1; continuously adjusting the adjustable parameter, for example, adjusting the adjustable parameter to 0.25, repeating the above steps 101 to 103 again to obtain a loss function of 0.01 … …, and performing iterative processing in this manner until the value of the loss function approaches to a value, which may be stopping the iterative processing or minimizing processing of the loss function, and determining the value as the value of the loss function after minimization.

In the embodiment of the application, the minimization of the loss function is realized in an iterative mode by adjusting the adjustable parameters of the parameterized quantum circuit, so that whether the quantum state to be detected is an entangled state or not is detected by the value of the loss function after minimization, the operation is simpler and easier, and the workload of quantum entanglement detection can be effectively reduced.

And S105, detecting whether the quantum state to be detected is an entangled state or not based on the value.

It can be understood that, after the loss function is minimized, whether the quantum state to be detected is an entangled state or not may be detected by determining whether the value of the loss function after minimization is positive or negative.

Optionally, the step S105 includes:

and under the condition that the value is less than 0, detecting to obtain that the quantum state to be detected is an entangled state.

That is, if the value of the loss function after minimization is a negative number, the quantum state to be measured is an entangled state. Therefore, whether the quantum state to be detected is an entangled state or not can be detected by judging whether the loss function value is negative or not, so that the quantum entangled detection mode is simpler and easier.

In the scheme provided by the embodiment of the application, the parameterized quantum circuits are respectively acted on four initial quantum states to obtain four first quantum states, the constructed four quantum gates are respectively acted on the quantum states to be detected to obtain four second quantum states, a loss function is obtained based on the four first quantum states and the four second quantum states, the loss function is subjected to minimization, and whether the quantum states to be detected are entangled or not is detected based on the value of the minimized loss function. Therefore, the loss function is obtained by constructing the quantum gate and combining the parameterized quantum circuit, whether the quantum state is entangled or not is detected based on the loss function, each matrix element in the density matrix of the whole quantum state is obtained by measuring without consuming a large amount of cost, and whether the quantum state to be detected is entangled or not can be detected only by constructing the quantum gates with a plurality of bases, so that the workload of quantum entanglement detection is greatly reduced, the quantum entanglement detection mode is simpler and more feasible, and the quantum entanglement detection method has higher practicability and efficiency.

In order to better understand the solution provided by the present application, it will be illustrated below by a specific example.

Step 1, obtaining a parameterized quantum circuit comprising adjustable parameters, for example, the parameterized quantum circuit is composed of a plurality of single quantum bit revolving gates and controlled back gates, wherein a plurality of revolving angles form a vector alpha, the vector alpha is the adjustable parameters of the parameterized quantum circuit, and the whole circuit is marked as U (theta).

Step 2, acting the parameterized quantum circuit U (theta) on four extracted and constructed initial quantum states |00>_ABTo obtain four identical first quantum states

Step 3. construct the quantum door

The quantum gate acts on the quantum state rho to be measured_ABTo obtain a second quantum state sigma₁。

Step 4. construct the quantum door

The quantum gate acts on the quantum state rho to be measured_ABTo obtain a second quantum state sigma₂。

Step 5. construct the quantum door

The quantum gate acts on the quantum state rho to be measured_ABTo obtain a second quantum state sigma₃。

Step 6. construct the quantum door

The quantum gate acts on the quantum state rho to be measured_ABTo obtain a second quantum state sigma₄。

Step 7. for the four first quantum states ψ obtained in step 2 above_ABAnd the four second quantum states obtained in the steps 3-6 can be obtained by using a Swap Test technologyComputing trace function C_j，C_j＝Tr(ψ_ABσ_j) Wherein j is 1, 2, 3, 4; e.g. σ_jRepresents the results obtained in the above steps 3 to 6 as σ₁、σ₂、σ₃And σ₄Tr (A) denotes the trace of a matrix A, i.e. the sum of the elements on the diagonal of the matrix A, e.g. Tr (psi)_ABσ₁) Is σ₁And psi_ABA matrix is formed.

And 8, calculating a loss function L ═ C based on the obtained trace function₁-C₂+C₃+C₄。

And 9, adjusting the adjustable parameter alpha by a gradient descent method or other optimization methods, repeating the steps 1-8 to carry out iterative processing, and minimizing the loss function L by a plurality of rounds of iteration.

Value L of the loss function if minimized_min<0, then the quantum state rho to be measured can be judged_ABIs in an entangled state. It should be noted that, when the iteration is performed in step 9 until the loss function is already smaller than 0, the iteration process may be stopped, and at this time, it may already be determined that the quantum state ρ to be measured is already in the quantum state ρ_ABIs in an entangled state.

In this embodiment, it is not necessary to consume a large amount of cost to measure each matrix element in the density matrix of the whole quantum state, and only a plurality of basic quantum gates need to be constructed to realize the detection of whether the quantum state to be detected is entangled, so that the workload of quantum entanglement detection is greatly reduced, and the quantum entanglement detection mode has higher practicability and high efficiency.

It should be noted that, in the above embodiment, two systems are taken as an example for description, and the quantum entanglement detection method provided in the embodiment of the present application may also be applied to quantum entanglement detection among multiple systems. For example, assume that both System A and System B are n qubit systems, and thus ρ_ABIs a quantum state of 2n qubits; alternatively, the quantum bits of the B system may be numbered, and B may be used_kRepresenting the kth qubit in the B system, i.e. B ═ B₁B₂…B_nThus quantum state ρ_ABCan be equivalent toIs shown as

Further, the quantum state can be detected based on the above-mentioned method in steps 1 to 9

Whether the quantum bit is entangled or not, a transposition operation needs to be performed on each quantum bit in the B system, the quantum gate corresponding to the required structure is a tensor product of the quantum gate corresponding to each quantum bit, for example, when n is 2, the quantum gate required to be constructed is in the form of

.., etc. If the detection result shows that the quantum state is entangled, then ρ can be judged_ABAre entangled. Therefore, quantum state entanglement detection between multiple quantum bit systems can be achieved, and the scheme provided by the embodiment of the application is wider in applicability.

To verify the feasibility of the quantum entanglement detection method provided by the present application, a specific example is described below.

In this embodiment, the quantum state involved is an isotropic state (isotropic state), specifically considering the isotropic state of a 2-qubit, defined by ρ_ABAnd (4) showing.

Where p denotes the parameters of this class of quantum states. And performing simulation test on the quantum state, and performing parameter iteration and random parameter initialization by adopting a gradient descent method. Rho is detected by the quantum entanglement detection method provided by the embodiment of the application_ABWhether the entangled state exists or not is verified through simulation tests, and the feasibility of the scheme provided by the embodiment of the application is verified, wherein the specific data are as follows:

based on the above table, it can be seen that the quantum entanglement detection method provided by the embodiment of the application has high accuracy and high feasibility.

Referring to fig. 2, an embodiment of the present application further provides a quantum entanglement detecting device. As shown in fig. 2, the quantum entanglement detection test apparatus 200 includes:

a first action module 201, configured to obtain parameterized quantum circuits, and respectively act on four initial quantum states to obtain four first quantum states, where the parameterized quantum circuits include adjustable parameters;

a second action module 202, configured to construct four quantum gates respectively, and act the four quantum gates on the quantum states to be measured respectively to obtain four second quantum states;

a first obtaining module 203, configured to obtain a loss function based on the four first quantum states and the four second quantum states;

a second obtaining module 204, configured to minimize the loss function and obtain a value of the loss function after minimization;

a detecting module 205, configured to detect whether the quantum state to be detected is an entangled state based on the value.

Optionally, the first obtaining module 203 is further configured to:

and obtaining a loss function based on the four trace functions.

Optionally, the four trace functions include a first trace function, a second trace function, a third trace function, and a fourth trace function; the first obtaining module 203 is further configured to:

Optionally, the second obtaining module 204 is further configured to:

Optionally, the probing module 205 is further configured to:

The quantum entanglement detecting device 200 provided in this embodiment can implement all technical solutions of the quantum entanglement detecting method embodiments described above, so that at least all technical effects described above can be achieved, and details are not described here.

It should be noted that the quantum entanglement detector 200 in this embodiment may be an electronic device as described in the above method embodiments, such as a recent quantum device.

There is also provided, in accordance with an embodiment of the present application, an electronic device, a readable storage medium, and a computer program product.

FIG. 3 illustrates a schematic block diagram of an example electronic device 300 that can be used to implement embodiments of the present disclosure. Electronic devices are intended to represent various forms of digital computers, such as laptops, desktops, workstations, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. The electronic device may 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 meant to be examples only, and are not meant to limit implementations of the disclosure described and/or claimed herein.

As shown in fig. 3, the electronic device 300 includes a computing unit 301 that can perform various appropriate actions and processes according to a computer program stored in a Read Only Memory (ROM)302 or a computer program loaded from a storage unit 308 into a Random Access Memory (RAM) 303. In the RAM 303, various programs and data required for the operation of the device 300 can also be stored. The calculation unit 301, the ROM 302, and the RAM 303 are connected to each other via a bus 304. An input/output (I/O) interface 305 is also connected to bus 304.

Various components in device 300 are connected to I/O interface 305, including: an input unit 306 such as a keyboard, a mouse, or the like; an output unit 307 such as various types of displays, speakers, and the like; a storage unit 308 such as a magnetic disk, optical disk, or the like; and a communication unit 309 such as a network card, modem, wireless communication transceiver, etc. The communication unit 309 allows the device 300 to exchange information/data with other devices via a computer network such as the internet and/or various telecommunication networks.

The computing unit 301 may be a variety of general and/or special purpose processing components having processing and computing capabilities. Some examples of the computing unit 301 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, a Digital Signal Processor (DSP), and any suitable processor, controller, microcontroller, and so forth. The computing unit 301 performs the various methods and processes described above, such as the quantum entanglement detection method. For example, in some embodiments, the quantum entanglement detection method may be implemented as a computer software program tangibly embodied in a machine-readable medium, such as storage unit 308. In some embodiments, part or all of the computer program may be loaded and/or installed onto device 300 via ROM 302 and/or communication unit 309. When the computer program is loaded into RAM 303 and executed by the computing unit 301, one or more steps of the quantum entanglement detection method described above may be performed. Alternatively, in other embodiments, the computing unit 301 may be configured to perform the quantum entanglement detection method by any other suitable means (e.g., by means of firmware).

Various implementations of the systems and techniques described here above may be implemented in digital electronic circuitry, integrated circuitry, Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Application Specific Standard Products (ASSPs), system on a chip (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and/or combinations thereof. These various embodiments may include: implemented in one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which may be special or general purpose, receiving data and instructions from, and transmitting data and instructions to, a storage system, at least one input device, and at least one output device.

Program code for implementing the methods 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, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowchart and/or block diagram to be performed. The program code may execute entirely on the machine, partly on the machine, as a stand-alone software package partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of this disclosure, a machine-readable medium may be a tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The 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, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, 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 disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

To provide for interaction with a user, the systems and techniques described here 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 a user; and a keyboard and a pointing device (e.g., a mouse or a trackball) by which a user can provide input to the computer. Other kinds of devices may also be used to provide for interaction with a user; for example, 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 may be received in any form, including acoustic, speech, or tactile input.

The systems and techniques described here can be implemented in a computing system that includes a back-end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front-end component (e.g., a user computer having a graphical user interface or a web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: local Area Networks (LANs), Wide Area Networks (WANs), and the Internet.

The computer system may include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.

It should be understood that various forms of the flows shown above may be used, with steps reordered, added, or deleted. For example, the steps described in the present disclosure may be executed in parallel, sequentially, or in different orders, as long as the desired results of the technical solutions disclosed in the present disclosure can be achieved, and the present disclosure is not limited herein.

The above detailed description should not be construed as limiting the scope of the disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made in accordance with design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A quantum entanglement detection method, comprising:

detecting whether the quantum state to be detected is an entangled state or not based on the value;

the step of obtaining a loss function based on the four first quantum states and the four second quantum states comprises:

and obtaining a loss function based on the four trace functions.

2. The method of claim 1, wherein the four trace functions comprise a first trace function, a second trace function, a third trace function, and a fourth trace function;

the step of obtaining a loss function based on the four trace functions includes:

3. The method of claim 1, wherein the step of minimizing the loss function and obtaining the value of the minimized loss function comprises:

4. The method of claim 1, wherein the step of detecting whether the quantum state to be detected is an entangled state based on the value comprises:

5. A quantum entanglement detector device, comprising:

the detection module is used for detecting whether the quantum state to be detected is an entangled state or not based on the value;

the first obtaining module is further configured to:

and obtaining a loss function based on the four trace functions.

6. The apparatus of claim 5, wherein the four trace functions comprise a first trace function, a second trace function, a third trace function, and a fourth trace function;

the first obtaining module is further configured to:

7. The apparatus of claim 5, wherein the second obtaining means is further configured to:

8. The apparatus of claim 5, wherein the detection module is further configured to:

9. An electronic device, comprising:

at least one processor; and

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 1-4.

10. A non-transitory computer readable storage medium having stored thereon computer instructions for causing the computer to perform the method of any one of claims 1-4.