Method for determining quantum circuit and method for observing multivariate high-order function

Abstract

The invention discloses a quantum circuit determination method and a method for observing a multivariate high-order function. The method comprises the following steps: acquiring an auxiliary quantum register, a first target quantum register and a second target quantum register; sequentially acting a Hadamard gate on an auxiliary quantum register, acting a first quantum logic gate virtually controlled by the auxiliary quantum register on the first target quantum register, and acting a second quantum logic gate actually controlled by the auxiliary quantum register on the first target quantum register, a third quantum logic gate actually controlled by the auxiliary quantum register acts on a second target quantum register, a NOT gate actually controlled by the auxiliary quantum register and the first target quantum register acts on the second target quantum register, a Hadamard gate acts on the auxiliary quantum register, and a target quantum circuit is obtained. The target quantum circuit can determine the observation value of the multivariate high-order function according to the observation probability of the quantum state of the auxiliary quantum register, and observation of the multivariate high-order function is achieved.

Description

Technical Field

[0001] This invention relates to the field of quantum computing technology, and in particular to a method for determining quantum circuits, a method, apparatus, electronic device, and computer-readable storage medium for observing multivariate higher-order functions. Background Technology

[0002] The general form of a quadratic function is f(x) = x T Ax+b T Let x + c be the vector A, where x is an n-dimensional vector, A is an n×n matrix, b is an n-dimensional vector, and c is a constant. Quadratic functions are an important concept in linear algebra, representing a mapping from vectors to real numbers. They are fundamental to the study of matrix theory and geometric spaces. In optimization theory, quadratic programming is a common type of optimization problem, with its objective function being a quadratic function. These problems have wide applications in economics, engineering, and other fields. In control system theory, the stability of a system is analyzed by constructing Lyapunov functions (usually positive definite quadratic functions).

[0003] The Hadamard-Test and Swap-Test circuits are existing and commonly used quantum circuits that can respectively implement the quadratic function f =<x|U|x> and f = ||<x|y> || 2 The observations are given by U, where U is a unitary matrix. For example, in the Hadamard-Test, if we let U = A, we can observe the first term x of the quadratic function. T The observation of Ax shows that both the Hadamard-Test and Swap-Test circuits can only observe specific quadratic functions. For non-standard quadratic functions, such as multivariate higher-order functions, current quantum computers are powerless due to a lack of corresponding hardware circuit design. Quantum computers are still in a period of rapid development, and how to design a circuit in a quantum computer to realize the observation of multivariate higher-order functions is a pressing technical problem that needs to be solved. Summary of the Invention

[0004] This application provides a method for determining quantum circuits, a method, apparatus, electronic device, and computer-readable storage medium for observing multivariate high-order functions. These methods enable the observation of multivariate high-order functions, thereby facilitating the design of corresponding quantum circuits in quantum computers and improving the hardware functionality of quantum computers.

[0005] The first aspect of this application provides a method for determining a quantum circuit, comprising:

[0006] Acquire the auxiliary quantum register, the first target quantum register, and the second target quantum register;

[0007] A Hadamard gate is sequentially applied to the auxiliary quantum register, a first quantum logic gate virtually controlled by the auxiliary quantum register is applied to the first target quantum register, a second quantum logic gate actually controlled by the auxiliary quantum register is applied to the first target quantum register, a third quantum logic gate actually controlled by the auxiliary quantum register is applied to the second target quantum register, a NOT gate actually controlled by the auxiliary quantum register and the first target quantum register is applied to the second target quantum register, and a Hadamard gate is applied to the auxiliary quantum register to obtain the target quantum circuit. The target quantum circuit is used to determine the observed value of a multivariate higher-order function based on the observation probability of the quantum state of the auxiliary quantum register. The first, second, and third quantum logic gates are used to encode the unknowns or coefficients of the unknowns in the multivariate higher-order function.

[0008] Optionally, the number of the second target quantum register, the third quantum logic gate, and the NOT gate are all k, where k is an integer greater than or equal to 1; the step of applying the third quantum logic gate, which is actually controlled by the auxiliary quantum register, to the second target quantum register, and applying the NOT gate, which is actually controlled by the auxiliary quantum register and the first target quantum register, to the second target quantum register includes:

[0009] Each third quantum logic gate controlled by the auxiliary quantum register is applied to the second target quantum register corresponding to each third quantum logic gate, and each NOT gate controlled by the auxiliary quantum register and the first target quantum register is applied to the second target quantum register corresponding to each third quantum logic gate.

[0010] Optionally, one of the first quantum logic gate, the second quantum logic gate, and the k third quantum logic gates is used to encode the coefficients of the unknowns in the multivariate higher-order function, and the other (k+1) are used to encode the unknowns in the multivariate higher-order function.

[0011] Optionally, the (k+1) unknowns are all different, and the target quantum circuit is used to determine the observed value of the (k+1)-ary polynomial function based on the observation probability of the quantum state of the auxiliary quantum register.

[0012] Optionally, all (k+1) unknowns are identical, and the target quantum circuit is used to determine the observed value of a univariate (k+1)-order function based on the observation probability of the quantum state of the auxiliary quantum register.

[0013] A second aspect of this application provides a method for observing multivariate higher-order functions, including:

[0014] A control signal is generated according to the target quantum circuit determined by the method as described in any of the first aspects;

[0015] The quantum states in the auxiliary quantum register and the target quantum register in the quantum chip are evolved by controlling the control signal.

[0016] The observation probability of the quantum state of the auxiliary quantum register is obtained by measuring the measurement signal of the auxiliary quantum register.

[0017] The observed value of the multivariate higher-order function is determined based on the observed probability.

[0018] A third aspect of this application provides a device for determining a quantum circuit, comprising:

[0019] The register acquisition unit is used to acquire the auxiliary quantum register, the first target quantum register, and the second target quantum register;

[0020] A circuit determination unit is used to sequentially apply a Hadamard gate to the auxiliary quantum register, apply a first quantum logic gate virtually controlled by the auxiliary quantum register to the first target quantum register, apply a second quantum logic gate actually controlled by the auxiliary quantum register to the first target quantum register, apply a third quantum logic gate actually controlled by the auxiliary quantum register to the second target quantum register, apply a NOT gate actually controlled by the auxiliary quantum register and the first target quantum register to the second target quantum register, and apply a Hadamard gate to the auxiliary quantum register to obtain a target quantum circuit. The target quantum circuit is used to determine the observed value of a multivariate higher-order function based on the observation probability of the quantum state of the auxiliary quantum register. The first, second, and third quantum logic gates are used to encode unknowns or coefficients of the unknowns in the multivariate higher-order function. A fourth aspect of this application provides an apparatus for observing multivariate higher-order functions, comprising:

[0021] A control signal generation unit is configured to generate a control signal according to the target quantum circuit determined by the method as described in any of the first aspects;

[0022] A quantum state evolution unit is used to control the evolution of quantum states in the auxiliary quantum register and the target quantum register in the quantum chip through the control signal;

[0023] An observation probability determination unit is used to measure the auxiliary quantum register based on a measurement signal to obtain the observation probability of the quantum state of the auxiliary quantum register;

[0024] An observation determination unit is used to determine the observation value of the multivariate higher-order function based on the observation probability.

[0025] A fourth aspect of this application provides an electronic device, including: a processor and a memory;

[0026] The processor is connected to a memory, wherein the memory is used to store computer programs and the processor is used to invoke the computer programs to execute the methods as described in the first or second aspect of the embodiments of this application.

[0027] The fifth aspect of this application provides a computer-readable storage medium storing a computer program, the computer program including program instructions, which, when executed by a processor, perform the methods as described in the first or second aspect of this application.

[0028] The method for determining a quantum circuit provided in this application involves acquiring an auxiliary quantum register, a first target quantum register, and a second target quantum register; sequentially applying a Hadamard gate to the auxiliary quantum register, applying a first quantum logic gate virtually controlled by the auxiliary quantum register to the first target quantum register, applying a second quantum logic gate actually controlled by the auxiliary quantum register to the first target quantum register, applying a third quantum logic gate actually controlled by the auxiliary quantum register to the second target quantum register, applying a NOT gate actually controlled by the auxiliary and first target quantum registers to the second target quantum register, and finally applying a Hadamard gate to the auxiliary quantum register to obtain the target quantum circuit. The first, second, and third quantum logic gates are used to encode unknowns or coefficients of unknowns in the multivariate high-order function. This target quantum circuit can determine the observed value of the multivariate high-order function based on the observation probability of the quantum state of the auxiliary quantum register, enabling the observation of the multivariate high-order function. This facilitates the design of corresponding quantum circuits in a quantum computer, thereby improving the hardware functionality of the quantum computer. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 An example system block diagram is shown for a method for determining quantum circuits and a method for observing multivariate higher-order functions provided in one embodiment of this application.

[0031] Figure 2A A schematic diagram of the structure of the Hadamard-Test circuit for measuring the real part of a standard quadratic function according to an embodiment of this application is shown;

[0032] Figure 2B A schematic diagram of the structure of the Hadamard-Test circuit for measuring the imaginary part of a standard quadratic function according to an embodiment of this application is shown;

[0033] Figure 3 A schematic diagram of the structure of a SWAP-Test circuit for measuring a perfect square function provided in one embodiment of this application is shown;

[0034] Figure 4 A flowchart illustrating a method for determining a quantum circuit according to an embodiment of this application is shown;

[0035] Figure 5 A schematic diagram of the structure of a quantum circuit for observing multivariate polynomial functions when J=4 is shown in one embodiment of this application;

[0036] Figure 6 A flowchart illustrating a method for observing multivariate higher-order functions according to an embodiment of this application is shown;

[0037] Figure 7 A schematic diagram of the structure of a quantum circuit determination device provided in one embodiment of this application is shown;

[0038] Figure 8 A schematic diagram of the structure of a device for observing multivariate higher-order functions according to an embodiment of this application is shown;

[0039] Figure 9 A schematic diagram of the structure of a computer device provided in one embodiment of this application is shown. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0041] Classical computers use transistors to encode information in binary data, such as bits, where each bit can represent a value of 1 or 0. These 1s and 0s act as switches to drive the functions of a classical computer. If there are n bits of data, there are 2^n possible classical states, and one state is represented at a time.

[0042] Quantum computers use quantum processors that operate on data represented by qubits, also known as quantum bits. A single qubit can represent the classical binary states "0" or "1", or a superposition of "0" and "1". Because it can represent a superposition of "0" and "1", a qubit can represent both "0" and "1" states simultaneously. For example, if there are n bits of data, then 2^n qubits can represent n bits of data. n A quantum state can be represented simultaneously. Furthermore, qubits in a superposition can be correlated with each other, a phenomenon known as entanglement, where the state of one qubit (whether 1, 0, or both) depends on the state of another qubit, and more information can be encoded within two entangled qubits. Based on the principles of superposition and entanglement, qubits enable quantum computers to perform functions that might be relatively complex and time-consuming for classical computers.

[0043] Please refer to Figure 1 This illustration shows an example system block diagram of a method for determining quantum circuits and a method for observing multivariate higher-order functions according to an embodiment of this application. System 100 may be a hybrid computing system comprising a combination of one or more quantum computers, quantum systems, and / or classical computers. Figure 1 In the example shown, system 100 may include a quantum system 110 and a classical computer 120. In one implementation, the quantum system 110 and the classical computer 120 may be configured to communicate via one or more wired and / or wireless connections (e.g., wireless networks). The quantum system 110 may include a quantum chipset consisting of one or more quantum chips, comprising various hardware components for processing data encoded in qubits. The quantum chipset may be a quantum computing core surrounded by infrastructure to protect the quantum chips from electromagnetic noise sources, mechanical vibration sources, heat sources, and other noise sources that can degrade the performance of the quantum chips. The classical computer 120 may be electronically integrated with the quantum system 110 via any suitable wired and / or wireless electronic connection.

[0044] exist Figure 1 In the example shown, quantum system 110 can be any suitable set of components capable of performing quantum operations on a physical system. Quantum operations, such as quantum gate operations, manipulate the quantum states of qubits to evolve and / or become entangled. Figure 1In the illustrated example embodiment, the quantum system 110 may include a measurement and control unit 111, an interface 112, and a quantum chip 113. In some embodiments, all or part of each of the measurement and control unit 111, interface 112, and quantum chip 113 may be located in a cryogenic environment to facilitate the performance of quantum operations. The quantum chip 113 may be any hardware capable of processing information using quantum states. This hardware may include multiple qubits and means for coupling or entanglement of the qubits to process information using quantum states. Qubits may include, but are not limited to, charge qubits, flux qubits, phase qubits, spin qubits, and ion qubits. The quantum chip may include a set of quantum logic gates configured to perform quantum logic operations on the qubits stored in a quantum register. The quantum gates may include one or more single-qubit gates, two-qubit gates, and / or other multi-qubit gates.

[0045] The measurement and control unit 111 can be any combination of digital computing devices capable of performing quantum computing (e.g., executing quantum circuits) in conjunction with interface 112. This digital computing device may include a digital processor and memory for storing and executing quantum instructions using interface 112. The digital computing device may also include a communication protocol device for receiving instructions and sending the results of the performed quantum computing to a classical computer. Additionally, the digital computing device may include a communication interface having interface 112. In one embodiment, the measurement and control unit 111 may be configured to receive classical instructions (e.g., from classical computer 120) and convert these classical instructions into measurement and control instructions for interface 112. The measurement and control instructions provided by the measurement and control unit 111 to interface 112 may be, for example, digital signals indicating which quantum gates in a quantum gate array need to be applied to the qubits to perform a specific function. Interface 112 may be configured to convert these digital signals into analog signals (e.g., analog pulses of microwave pulses), which can be used to apply quantum gates to the qubits to manipulate the interactions between the qubits.

[0046] Interface 112 may be a classical-quantum interface, comprising a combination of devices capable of receiving instructions from the integrated measurement and control unit 111 and converting those instructions into a means for implementing quantum operations. In one embodiment, interface 112 may convert instructions from the integrated measurement and control unit 111 into drive signals capable of driving or manipulating qubits, and / or applying quantum gates to qubits. Additionally, interface 112 may be configured to convert signals received from the quantum chip 113 into digital signals capable of being processed and transmitted by the integrated measurement and control unit 111. Devices included in interface 112 may include, but are not limited to, digital-to-analog converters, analog-to-digital converters, waveform generators, attenuators, amplifiers, optical fibers, lasers, and filters. Interface 112 may further include circuitry configured to measure multiple qubits after the application of quantum gates, wherein the measurements may produce results represented in classical bits. Each measurement performed by interface 112 may be read out to a device connected to the quantum system 110, such as a classical computer 120. The multiple measurement results provided by interface 112 may represent probabilistic results.

[0047] The classical computer 120 can include hardware components such as a processor and storage devices (e.g., including memory devices and classical registers) for processing data encoded in classical bits. In one embodiment, the classical computer 120 can be configured to provide the quantum system 110 with various control signals, instructions, and data encoded in classical bits. Further, quantum states measured by the quantum system 110 can be read out by the classical computer 120, and the classical computer 120 can store the measured quantum states as classical bits in classical registers. In one embodiment, the classical computer 120 can be any suitable combination of computer-executable hardware and / or computer-executable software capable of executing the preparation module 121 to perform quantum computation using data stored in the data storage module 122 as part of the construction and computation. The data storage module 122 can be a repository for data to be analyzed using quantum computing algorithms and the results of that analysis. The preparation module 121 can be a program or module capable of preparing classical data from the data storage module 122 as part of a quantum circuit implementation. Preparation module 121 can be instantiated as part of a larger algorithm, such as an application programming interface (API) function call, or by resolving hybrid classical-quantum computing into aspects of quantum and classical computing. For example, preparation module 121 can generate instructions for creating quantum circuits using quantum gates. In an embodiment, such instructions can be stored by the measurement and control unit 111 and can be instantiated by components of interface 112 to execute, allowing quantum operations of quantum gates to be performed on quantum chip 113.

[0048] The classic computer 120 may be a laptop computer, desktop computer, vehicle-integrated computer, smart mobile device, tablet device, and / or any other suitable classic computing device. Additionally or alternatively, the classic computer 120 may also operate as part of a cloud computing service model, such as Software as a Service (SaaS), Platform as a Service (PaaS), or Infrastructure as a Service (IaaS). The classic computer 120 may also reside in a cloud computing deployment model, such as a private cloud, community cloud, public cloud, or hybrid cloud.

[0049] The general form of a quadratic function is f(x) = x T Ax+b T x+c, where x is a k-dimensional vector, A is an n×n matrix, b is an n-dimensional vector, and c is a constant. For the first term:

[0050]

[0051] The Hadamard-Test circuit is an existing and commonly used quantum circuit that can be used to implement the quadratic function f = ...<x|U|x> The observations are given, where U equals matrix A in the quadratic function, requiring U to be a specific unitary operator. For the real part of , the Hadamard-Test circuit is as follows: Figure 2A As shown. In the diagram, H represents the Hadamard door. U x It is an encoding circuit of |x>, with U x |0>=|x>. The quantum state after the above circuit has run is:

[0052]

[0053] The probabilities of observing the first bit being 0 and 1 are as follows:

[0054]

[0055] It is obvious that P(0) - P(1) =<x|U|x> .

[0056] For the imaginary part of f, the Hadamard-Test circuit is as follows: Figure 2B As shown. Where the S-gate is...

[0057]

[0058] The Swap Test is a technique commonly used to compare the similarity between vectors. This test constructs a circuit containing the target state and uses quantum interference to measure the inner product between these states, thus achieving a similarity between f = |||.<x|y> || 2The observations are defined in the Swap-Test, where x and y are unknowns. For example, if |x>=|y> and the function is in the real number field, |x>=[x1,x2], then the observable function of Swap-Test is [x1,x2]. It is a quartic function. If |y> is a constant vector, for example, |y>=[a1,a2], then the observable function of Swap-Test is g=(a1x2+a2x2). 2 It is a quadratic function. In short, the Swap-Test function observes a perfect square function.

[0059] like Figure 3 As shown, Figure 3 A schematic diagram of a SWAP-Test circuit for measuring perfect square functions according to an embodiment of this application is shown. x It is the encoding circuit of |x>, U y It is an encoding circuit of |y>, with U y |0>=|y>。 The quantum state after the above circuit has run is:

[0060]

[0061] The probabilities of observing the first bit being 0 and 1 are as follows:

[0062]

[0063] It is obvious that P(0) - P(1) = ||<x|y> || 2 .

[0064] The Hadamard-Test circuit and the Swap-Test circuit can respectively realize the observation of different forms of quadratic functions. The Hadamard-Test circuit realizes f i = <x|U i The observation of |x>, here limited to U i It must be a unitary operator. The application scope of the Hadamard-Test circuit is extended somewhat; for example, the objective function g can be written as...

[0065] g =<x|A|x> #(6)

[0066] Here, A is a general matrix, if A can be decomposed into a unitary matrix U. l linear combination The objective function can then be written as

[0067]

[0068] At this point, observation can be performed using the Hadamard-Test circuit. <x|U iThe values ​​of |x> are summed to obtain the value of the objective function g. A total of L such observations are required.

[0069] If the objective function is not a quadratic function, but can be written as

[0070]

[0071] or

[0072]

[0073] Then by observing each f i By multiplying these values, we can obtain the value of an even-degree function of a specific form. A total of L or LK such observations are required.

[0074] The Swap-Test circuit is used to observe a quadratic function of the form f = |||<x|y> || 2 In particular, when |x> and |y> are both real numbers,

[0075] It can be seen that both the Hadamard-Test circuit and the Swap-Test circuit can only observe specific quadratic functions. Even after the extension, they can only observe even-degree functions of a specific form, and the number of observations is L or LK.

[0076] Based on this, embodiments of this application provide a method for determining quantum circuits and a method, apparatus, electronic device, and computer-readable storage medium for observing multivariate higher-order functions.

[0077] Please refer to Figure 4 This document illustrates a flowchart of a method for determining a quantum circuit according to an embodiment of this application. This method can be applied to computer devices, which refer to electronic devices capable of data computation and processing. For example, the executing entity for each step could be... Figure 1 The method can include the following steps: (The example shown is a quantum computer or a classical computer.)

[0078] Step 401: Obtain the auxiliary quantum register, the first target quantum register, and the second target quantum register;

[0079] Step 402: Apply a Hadamard gate to the auxiliary quantum register in sequence, apply a first quantum logic gate virtually controlled by the auxiliary quantum register to the first target quantum register, apply a second quantum logic gate actually controlled by the auxiliary quantum register to the first target quantum register, apply a third quantum logic gate actually controlled by the auxiliary quantum register to the second target quantum register, apply a NOT gate actually controlled by the auxiliary quantum register and the first target quantum register to the second target quantum register, and apply a Hadamard gate to the auxiliary quantum register to obtain the target quantum circuit. The target quantum circuit is used to determine the observed value of the multivariate higher-order function based on the observation probability of the quantum state of the auxiliary quantum register. The first quantum logic gate, the second quantum logic gate, and the third quantum logic gate are used to encode the unknown quantity or the coefficient of the unknown quantity in the multivariate higher-order function.

[0080] A quantum register is a fundamental component of a quantum computer; it is a collection of at least one qubit. An auxiliary quantum register consists of one qubit. The target quantum register consists of n qubits, where n is determined by the number of bits required to encode the unknown quantity.

[0081] Among them, a real-controlled quantum logic gate refers to a quantum logic gate that only operates when the quantum state of the control bit is |1>, while a virtual-controlled quantum logic gate refers to a quantum logic gate that only operates when the quantum state of the control bit is |0>.

[0082] Multivariate higher-order functions are functions with multiple variables and at least one unknown quantity whose degree is greater than or equal to 1. These functions have wide applications in mathematical analysis, engineering calculations, physics, and other fields. In practical applications, multivariate higher-order function models can be used to describe complex system behavior, such as chemical reaction kinetics and economic forecasting models. For example, the observed function is...

[0083]

[0084] Where, x j Let J represent the j-th unknown quantity, where J is the total number of unknown quantities. If there are multiple unknown quantities that are equal, then it can represent a multivariate higher-order function.

[0085] For example, if J = 2, and only two unknowns x and y are included, the operation rules for the observed function are as follows:

[0086]

[0087] Where, x p Let y represent the p-th amplitude component of the quantum state |x>. pLet p represent the p-th amplitude component of the quantum state |y>. The operational rules for multiple unknowns can refer to the operational rules for the two unknowns described above.

[0088] In one specific embodiment, the number of the second target quantum register, the third quantum logic gate, and the NOT gate are all k, where k is an integer greater than or equal to 1; the step of applying the third quantum logic gate, which is actually controlled by the auxiliary quantum register, to the second target quantum register, and applying the NOT gate, which is actually controlled by the auxiliary quantum register and the first target quantum register, to the second target quantum register includes:

[0089] Each third quantum logic gate controlled by the auxiliary quantum register is applied to the second target quantum register corresponding to each third quantum logic gate, and each NOT gate controlled by the auxiliary quantum register and the first target quantum register is applied to the second target quantum register corresponding to each third quantum logic gate.

[0090] For example, if k=2 and J=4, then... Figure 5 As shown, Figure 5 A schematic diagram of the structure of a quantum circuit for observing multivariate polynomial functions when J=4 is shown in one embodiment of this application.

[0091] The observation function for J=4 is:

[0092]

[0093] The first quantum logic gate is U x The auxiliary quantum register acts as a virtual control over the first target quantum register, used to encode the unknown quantity x, U. x |0>=|x>;The second quantum logic gate is U y The auxiliary quantum register acts as a control over the first target quantum register, used to encode the unknown quantity y, U. y |0>=|y>;The third quantum logic gate is U z and U w U z The auxiliary quantum register acts as a control over the first second target quantum register, used to encode the unknown quantity z, U. z |0>=|z>;U z The corresponding NOT gate is controlled by the auxiliary quantum register and the first target quantum register, which in turn act on the first second target quantum register; U w The auxiliary quantum register acts as a control over the second target quantum register, used to encode the unknowns w and U. w |0>=|w>,U wThe corresponding NOT gate is controlled by the auxiliary quantum register and the first target quantum register, which in turn control the second target quantum register.

[0094] like Figure 5 As shown:

[0095] First, after passing through the H gate, the quantum state becomes...

[0096]

[0097] After passing through four more controlled U gates, the quantum state becomes

[0098]

[0099] After a subsequent CNOT gate, the quantum state becomes

[0100]

[0101] here <p * |p00>=0, meaning |p * > is a basis vector perpendicular to |p00>, which is a basis we do not care about.

[0102] Finally, an H-gate is applied, and the quantum state becomes...

[0103]

[0104] Obviously, the probability of observing 0 or 1 is

[0105]

[0106] Therefore, we have P0 - P1 = ∑ p x p y p z p w p .

[0107] If J = n, and the initial state is |0…0>, then:

[0108] First, it passes through the first H gate and becomes...

[0109] After passing through the real and virtual control gates on the second bit, the quantum state becomes

[0110]

[0111] Then, by applying a real-control gate to subsequent bits, the quantum state becomes

[0112]

[0113] After passing through all CNOT gate circuits, the quantum state becomes

[0114]

[0115] The last bit acts on the H gate, and...

[0116]

[0117] therefore Clearly, when x, y, z, and w are all real numbers, the above expression = ixiyiziwi…

[0118] As can be seen, the method for determining the quantum circuit provided in this application involves obtaining an auxiliary quantum register, a first target quantum register, and a second target quantum register; sequentially applying a Hadamard gate to the auxiliary quantum register, applying a first quantum logic gate virtually controlled by the auxiliary quantum register to the first target quantum register, applying a second quantum logic gate actually controlled by the auxiliary quantum register to the first target quantum register, applying a third quantum logic gate actually controlled by the auxiliary quantum register to the second target quantum register, applying a NOT gate actually controlled by the auxiliary quantum register and the first target quantum register to the second target quantum register, and applying a Hadamard gate to the auxiliary quantum register to obtain the target quantum circuit. The first, second, and third quantum logic gates are used to encode the unknowns or coefficients of the unknowns in the multivariate high-order function. This target quantum circuit can determine the observed value of the multivariate high-order function based on the observation probability of the quantum state of the auxiliary quantum register, enabling the observation of the multivariate high-order function. This facilitates the design of corresponding quantum circuits in a quantum computer, thereby improving the hardware functionality of the quantum computer.

[0119] In the above embodiment where J=4:

[0120]

[0121] The coefficients of each unknown are 1. If the coefficients are not 1, the corresponding observation function can be encoded by encoding one or more of the unknowns with their corresponding coefficients.

[0122] In one specific embodiment, one of the first quantum logic gate, the second quantum logic gate, and the k third quantum logic gates is used to encode the coefficients of the unknowns in the multivariate higher-order function, and the other (k+1) are used to encode the unknowns in the multivariate higher-order function.

[0123] Specifically, the (k+1) unknowns are all different, and the target quantum circuit is used to determine the observed value of the (k+1)-ary polynomial function based on the observation probability of the quantum state of the auxiliary quantum register.

[0124] For example, in the embodiment where J=4 above, let Ux =U a Realization coefficient a p The encoding U a |0>=|a p >, then It is a ternary polynomial function.

[0125] Specifically, all (k+1) unknowns are identical, and the target quantum circuit is used to determine the observed value of a univariate (k+1)-order function based on the observation probability of the quantum state of the auxiliary quantum register.

[0126] For example, in the embodiment where J=4 above, let U x =U a Realization coefficient a p The encoding U a |0>=|a p >, let U y =U z =U w Realization coefficient y p The encoding U y |0>=|y p >, then It is a cubic function in one variable.

[0127] Other multivariate higher-order functions can be easily derived using the methods described above, and will not be repeated here.

[0128] Please refer to Figure 6 This document illustrates a flowchart of a method for observing multivariate higher-order functions according to an embodiment of this application. This method can be applied to computer devices, which refer to electronic devices capable of data computation and processing. For example, the executing entity for each step can be... Figure 1 The method can include the following steps: (The example shown is a quantum computer or a classical computer.)

[0129] Step 601: The determined target quantum circuit generates a control signal;

[0130] Step 602: Control the evolution of the quantum states in the auxiliary quantum register and the target quantum register in the quantum chip through the control signal;

[0131] Step 603: Measure the auxiliary quantum register according to the measurement signal to obtain the observation probability of the quantum state of the auxiliary quantum register;

[0132] Step 604: Determine the observed value of the multivariate higher-order function based on the observed probability.

[0133] Furthermore, before the determined target quantum circuit generates the control signal, the method further includes:

[0134] Acquire the auxiliary quantum register, the first target quantum register, and the second target quantum register;

[0135] A Hadamard gate is sequentially applied to the auxiliary quantum register, a first quantum logic gate virtually controlled by the auxiliary quantum register is applied to the first target quantum register, a second quantum logic gate actually controlled by the auxiliary quantum register is applied to the first target quantum register, a third quantum logic gate actually controlled by the auxiliary quantum register is applied to the second target quantum register, a NOT gate actually controlled by the auxiliary quantum register and the first target quantum register is applied to the second target quantum register, and a Hadamard gate is applied to the auxiliary quantum register to obtain the target quantum circuit. The target quantum circuit is used to determine the observed value of a multivariate higher-order function based on the observation probability of the quantum state of the auxiliary quantum register. The first, second, and third quantum logic gates are used to encode the unknowns or coefficients of the unknowns in the multivariate higher-order function.

[0136] Optionally, the number of the second target quantum register, the third quantum logic gate, and the NOT gate are all k, where k is an integer greater than or equal to 1; the step of applying the third quantum logic gate, which is actually controlled by the auxiliary quantum register, to the second target quantum register, and applying the NOT gate, which is actually controlled by the auxiliary quantum register and the first target quantum register, to the second target quantum register includes:

[0137] Each third quantum logic gate controlled by the auxiliary quantum register is applied to the second target quantum register corresponding to each third quantum logic gate, and each NOT gate controlled by the auxiliary quantum register and the first target quantum register is applied to the second target quantum register corresponding to each third quantum logic gate.

[0138] Optionally, one of the first quantum logic gate, the second quantum logic gate, and the k third quantum logic gates is used to encode the coefficients of the unknowns in the multivariate higher-order function, and the other (k+1) are used to encode the unknowns in the multivariate higher-order function.

[0139] Optionally, the (k+1) unknowns are all different, and the target quantum circuit is used to determine the observed value of the (k+1)-element linear function based on the observation probability of the quantum state of the auxiliary quantum register.

[0140] Optionally, all (k+1) unknowns are identical, and the target quantum circuit is used to determine the observed value of a univariate (k+1)-order function based on the observation probability of the quantum state of the auxiliary quantum register.

[0141] The specific implementation of each step in this method embodiment is described in the previous embodiment and will not be repeated here.

[0142] Figure 7 A schematic diagram of the structure of a quantum circuit determination device provided in one embodiment of this application is shown.

[0143] The device includes:

[0144] Register acquisition unit 701 is used to acquire auxiliary quantum register, first target quantum register and second target quantum register;

[0145] The circuit determination unit 702 is used to sequentially apply a Hadamard gate to the auxiliary quantum register, apply a first quantum logic gate virtually controlled by the auxiliary quantum register to the first target quantum register, apply a second quantum logic gate actually controlled by the auxiliary quantum register to the first target quantum register, apply a third quantum logic gate actually controlled by the auxiliary quantum register to the second target quantum register, apply a NOT gate actually controlled by the auxiliary quantum register and the first target quantum register to the second target quantum register, and apply a Hadamard gate to the auxiliary quantum register to obtain a target quantum circuit. The target quantum circuit is used to determine the observed value of a multivariate higher-order function based on the observation probability of the quantum state of the auxiliary quantum register. The first quantum logic gate, the second quantum logic gate, and the third quantum logic gate are used to encode the unknown quantity or the coefficient of the unknown quantity in the multivariate higher-order function.

[0146] Figure 8 A schematic diagram of a device for observing multivariate higher-order functions according to an embodiment of this application is shown. The device includes:

[0147] A control signal generation unit 801 is configured to generate a control signal according to the target quantum circuit determined by the method as described in any one of claims 1-5;

[0148] The quantum state evolution unit 802 is used to control the evolution of the quantum states in the auxiliary quantum register and the target quantum register in the quantum chip through the control signal;

[0149] The observation probability determination unit 803 is used to measure the auxiliary quantum register according to the measurement signal to obtain the observation probability of the quantum state of the auxiliary quantum register;

[0150] The observation value determination unit 804 is used to determine the observation value of the multivariate higher-order function based on the observation probability.

[0151] Figure 9The diagram illustrates the structure of a computer device according to an embodiment of this application, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the functions of the computer system for determining quantum circuits or for observing multivariate higher-order functions in any of the above embodiments.

[0152] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a computer, causes the computer to perform the functions of a computer system for determining quantum circuits or for observing multivariate higher-order functions in any of the above embodiments.

[0153] This application also provides a computer program product containing instructions that, when executed by a computer, cause the computer to perform the functions of a computer system for determining a quantum circuit or for observing multivariate higher-order functions in any of the above embodiments.

[0154] It is understood that the specific examples in this application are only intended to help those skilled in the art better understand the implementation methods of this application, and are not intended to limit the scope of the invention.

[0155] It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not limit the implementation process of the embodiments of this application in any way.

[0156] It is understood that the various implementation methods described in this application can be implemented individually or in combination, and the implementation methods in this application are not limited in this respect.

[0157] Unless otherwise stated, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items. The singular forms "a," "the," and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0158] It is understood that the processor in the embodiments of this application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiments can be completed by the integrated logic circuits in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory; the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0159] It is understood that the memory in the embodiments of this application may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Specifically, non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory may be random access memory (RAM). It should be noted that the memory in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0160] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0161] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the aforementioned method implementations, and will not be repeated here.

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

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

[0164] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

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

[0166] The above are merely specific embodiments of this application, but the scope of protection of this invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this invention should be determined by the scope of the claims.

Claims

1. A method for determining a quantum circuit, characterized in that, include: Acquire the auxiliary quantum register, the first target quantum register, and the second target quantum register; A Hadamard gate is sequentially applied to the auxiliary quantum register, a first quantum logic gate virtually controlled by the auxiliary quantum register is applied to the first target quantum register, a second quantum logic gate actually controlled by the auxiliary quantum register is applied to the first target quantum register, a third quantum logic gate actually controlled by the auxiliary quantum register is applied to the second target quantum register, a NOT gate actually controlled by the auxiliary quantum register and the first target quantum register is applied to the second target quantum register, and a Hadamard gate is applied to the auxiliary quantum register to obtain the target quantum circuit. The target quantum circuit is used to determine the observed value of a multivariate higher-order function based on the observation probability of the quantum state of the auxiliary quantum register. The first, second, and third quantum logic gates are used to encode the unknowns or coefficients of the unknowns in the multivariate higher-order function.

2. The method according to claim 1, characterized in that, The number of the second target quantum register, the third quantum logic gate, and the NOT gate are all k, where k is an integer greater than or equal to 1; the step of applying the third quantum logic gate, which is actually controlled by the auxiliary quantum register, to the second target quantum register, and applying the NOT gate, which is actually controlled by the auxiliary quantum register and the first target quantum register, to the second target quantum register includes: Each third quantum logic gate controlled by the auxiliary quantum register is applied to the second target quantum register corresponding to each third quantum logic gate, and each NOT gate controlled by the auxiliary quantum register and the first target quantum register is applied to the second target quantum register corresponding to each third quantum logic gate.

3. The method according to claim 2, characterized in that, One of the first quantum logic gate, the second quantum logic gate, and the k third quantum logic gates is used to encode the coefficients of the unknowns in the multivariate higher-order function, and the other (k+1) are used to encode the unknowns in the multivariate higher-order function.

4. The method according to claim 3, characterized in that, The (k+1) unknowns are all different, and the target quantum circuit is used to determine the observed value of the (k+1)-ary polynomial function based on the observation probability of the quantum state of the auxiliary quantum register.

5. The method according to claim 3, characterized in that, All (k+1) unknowns are identical, and the target quantum circuit is used to determine the observed value of a univariate (k+1)-order function based on the observation probability of the quantum state of the auxiliary quantum register.

6. A method for observing multivariate higher-order functions, characterized in that, include: The target quantum circuit determined by the method according to any one of claims 1-5 generates a control signal; The quantum states in the auxiliary quantum register and the target quantum register in the quantum chip are evolved by controlling the control signal. The observation probability of the quantum state of the auxiliary quantum register is obtained by measuring the measurement signal of the auxiliary quantum register. The observed value of the multivariate higher-order function is determined based on the observed probability.

7. A device for determining a quantum circuit, characterized in that, include: The register acquisition unit is used to acquire the auxiliary quantum register, the first target quantum register, and the second target quantum register; A circuit determination unit is used to sequentially apply a Hadamard gate to the auxiliary quantum register, apply a first quantum logic gate virtually controlled by the auxiliary quantum register to the first target quantum register, apply a second quantum logic gate actually controlled by the auxiliary quantum register to the first target quantum register, apply a third quantum logic gate actually controlled by the auxiliary quantum register to the second target quantum register, apply a NOT gate actually controlled by the auxiliary quantum register and the first target quantum register to the second target quantum register, and apply a Hadamard gate to the auxiliary quantum register to obtain a target quantum circuit. The target quantum circuit is used to determine the observed value of a multivariate higher-order function based on the observation probability of the quantum state of the auxiliary quantum register. The first quantum logic gate, the second quantum logic gate, and the third quantum logic gate are used to encode the unknown quantity or the coefficient of the unknown quantity in the multivariate higher-order function.

8. A device for observing multivariate higher-order functions, characterized in that, include: A control signal generation unit is configured to generate a control signal according to the target quantum circuit determined by the method as described in any one of claims 1-5; A quantum state evolution unit is used to control the evolution of quantum states in the auxiliary quantum register and the target quantum register in the quantum chip through the control signal; An observation probability determination unit is used to measure the auxiliary quantum register based on a measurement signal to obtain the observation probability of the quantum state of the auxiliary quantum register; An observation determination unit is used to determine the observation value of the multivariate higher-order function based on the observation probability.

9. An electronic device, characterized in that, include: Processor and memory; The processor is connected to a memory, wherein the memory is used to store a computer program, and the processor is used to invoke the computer program to execute the method as described in claim 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, the computer program including program instructions that, when executed by a processor, perform the method as described in claim 7.

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