Noise immune quantum gate design method and device, storage medium and electronic equipment
By synthesizing quantum control pulse sequences through Lie algebra analysis and geometric optimization of symmetry-protected subspaces, the problem of qubit noise influence is solved, improving the efficiency and robustness of quantum computing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-16
- Publication Date
- 2026-04-03
AI Technical Summary
In real physical systems, qubits are affected by noise, which leads to distortion of quantum gate operations and affects the correctness and scalability of quantum computing. Although existing methods improve robustness, they reduce computational efficiency.
By obtaining the physical noise model of the target quantum system, Lie algebra symmetry analysis is performed to generate a symmetry-protected subspace. Based on the optimization of symmetric manifolds, a quantum control pulse sequence is synthesized, the lower limit of theoretical fidelity is verified, and the quantum control pulse sequence is output.
It improves the computational efficiency of quantum computing, reduces the stringent requirements for pulse control precision, and reduces the complexity and time overhead introduced by additional control layers.
Smart Images
Figure CN121787600A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of quantum computing technology, specifically to a noise-immune quantum gate design method, apparatus, storage medium, and electronic device. Background Technology
[0002] The core of quantum computing lies in performing precise quantum logic gate operations on qubits. However, in real physical systems, qubits are inevitably affected by noise from environmental decoherence effects (such as energy relaxation and phase damping) and system imperfections (such as pulse amplitude errors, frequency detuning, and timing jitter). This noise leads to distortion in quantum gate operations, causing deviations between the actual executed quantum gate and the target quantum gate, i.e., a decrease in gate fidelity, which ultimately seriously affects the correctness of quantum computing and the scalability of quantum computers.
[0003] To address the aforementioned noise challenges, current methods primarily employ error mitigation by adding an additional control layer beyond the basic gate operations. However, while this approach improves operational robustness to some extent, it significantly reduces the computational efficiency of quantum computing. Summary of the Invention
[0004] This application provides a noise-immune quantum gate design method, apparatus, storage medium, and electronic device, which can improve the computational efficiency of quantum computing.
[0005] In a first aspect, embodiments of this application provide a noise-immune quantum gate design method, including: Obtain the gauge information of the target quantum gate and the physical noise model of the target quantum system; Based on the physical noise model, a Lie algebra symmetry analysis is performed on the total Hamiltonian of the target quantum system to generate a symmetry-protected subspace, which is immune to the noise channels of the physical noise model. Based on the aforementioned specification information, quantum control pulse sequences are synthesized through geometric optimization on the symmetric manifold corresponding to the symmetric protected subspace. Based on the mathematical properties of the symmetry-protected subspace, the theoretical fidelity lower limit of the quantum gate realized by the quantum control pulse sequence is verified; When the theoretical fidelity lower limit meets the preset conditions, the theoretical fidelity lower limit and the quantum control pulse sequence are output.
[0006] In the noise-immune quantum gate design method provided in this application embodiment, the step of performing Lie algebra symmetry analysis on the total Hamiltonian of the target quantum system according to the physical noise model to generate a symmetry-protected subspace includes: Based on the physical noise model and the target quantum system, construct the total Hamiltonian; Determine the dynamic Lie algebra corresponding to the total Hamiltonian; The symmetric protected subspace is determined based on the aforementioned dynamic Lie algebra.
[0007] In the noise-immune quantum gate design method provided in this application embodiment, the step of constructing the total Hamiltonian based on the physical noise model and the target quantum system includes: The main noise channels in the physical noise model are characterized as perturbation Hamiltonians. Obtain the control Hamiltonian of the target quantum system; The perturbation Hamiltonian and the control Hamiltonian are combined into a total Hamiltonian.
[0008] In the noise-immune quantum gate design method provided in this application embodiment, the step of determining the symmetry-protected subspace based on the dynamic Lie algebra includes: In the dynamic Lie algebra, a subalgebra that commutes with the perturbation Hamiltonian is determined; The subspace generated by the subalgebra is defined as a symmetric protected subspace.
[0009] In the noise-immune quantum gate design method provided in this application embodiment, determining the subalgebra that commutes with the perturbation Hamiltonian in the dynamic Lie algebra includes: Calculate all generators of the dynamic Lie algebra and the commutators of the perturbation Hamiltonian; Select a set of generators that satisfy either that the commutator is zero or that the commutator belongs to the perturbation Hamiltonian itself; The subalgebra of the Lie algebra generated from the selected set of generators that commutes with the perturbation Hamiltonian.
[0010] In the noise-immune quantum gate design method provided in this application embodiment, the step of synthesizing a quantum control pulse sequence on the symmetric manifold corresponding to the symmetry protected subspace through geometric optimization based on the canonical information includes: Based on the aforementioned specification information, the target evolution operator of the target quantum gate is determined; A geometric optimization model is constructed with the quantum evolution operator realized on the symmetric manifold approximating the target evolution operator as the objective function; Within the Riemann space formed by the symmetric manifold, the geometric optimization model is iteratively solved to obtain a quantum control pulse sequence.
[0011] The noise-immune quantum gate design method provided in this application embodiment is applicable to various quantum computing physics implementation platforms, including superconducting qubits, ion traps, solid-state spin, and photonic quantum.
[0012] Secondly, embodiments of this application provide a noise-immune quantum gate design device, comprising: The acquisition unit is used to acquire the gauge information of the target quantum gate and the physical noise model of the target quantum system; The analysis unit is used to perform Lie algebra symmetry analysis on the total Hamiltonian of the target quantum system according to the physical noise model, so as to generate a symmetry-protected subspace, which is immune to the noise channel of the physical noise model. A synthesis unit is used to synthesize a quantum-controlled pulse sequence on the symmetric manifold corresponding to the symmetric protected subspace through geometric optimization based on the canonical information. The authentication unit is used to authenticate the theoretical fidelity lower bound of the quantum gate realized by the quantum control pulse sequence based on the mathematical properties of the symmetry protected subspace. The output unit is used to output the theoretical fidelity lower limit and the quantum control pulse sequence when the theoretical fidelity lower limit meets the preset conditions.
[0013] Thirdly, this application provides a storage medium storing a plurality of instructions adapted for loading by a processor to execute the noise-immune quantum gate design method described in any of the preceding claims.
[0014] Fourthly, this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the noise-immune quantum gate design method described in any of the preceding claims.
[0015] In summary, the noise-immune quantum gate design method provided in this application includes: acquiring the gauge information of the target quantum gate and the physical noise model of the target quantum system; performing Lie algebra symmetry analysis on the total Hamiltonian of the target quantum system according to the physical noise model to generate a symmetry-protected subspace, which is immune to the noise channels of the physical noise model; synthesizing a quantum control pulse sequence through geometric optimization on the symmetric manifold corresponding to the symmetry-protected subspace based on the gauge information; verifying the theoretical fidelity lower bound of the quantum gate realized by the quantum control pulse sequence based on the mathematical properties of the symmetry-protected subspace; and outputting the theoretical fidelity lower bound and the quantum control pulse sequence when the theoretical fidelity lower bound meets a preset condition. This application embodiment can improve the computational efficiency of quantum computing. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram illustrating an application scenario of the noise-immune quantum gate design method provided in the embodiments of this application.
[0018] Figure 2 This is a flowchart illustrating the noise-immune quantum gate design method provided in the embodiments of this application.
[0019] Figure 3 This is a schematic diagram of the noise-immune quantum gate design device provided in the embodiments of this application.
[0020] Figure 4 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation
[0021] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.
[0022] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of this application may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.
[0023] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.
[0024] In the following description, the use of suffixes such as "module," "part," or "unit" to denote elements is solely for the purpose of illustrative purposes and has no specific meaning in itself. Therefore, "module," "part," or "unit" may be used interchangeably.
[0025] In the description of this application, it should be noted that the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0026] In real physical systems, qubits are inevitably affected by noise from environmental decoherence effects (such as energy relaxation and phase damping) and system imperfections (such as pulse amplitude errors, frequency detuning, and timing jitter). This noise leads to distortion in quantum gate operations, causing deviations between the actual executed quantum gate and the target quantum gate, i.e., a decrease in gate fidelity, which ultimately seriously affects the correctness of quantum computing and the scalability of quantum computers.
[0027] To address the aforementioned noise challenges, current methods primarily employ error mitigation by adding an additional control layer beyond the basic gate operations. However, while this approach improves operational robustness to some extent, it significantly reduces the computational efficiency of quantum computing.
[0028] Based on this, embodiments of this application provide a noise-immune quantum gate design method, apparatus, storage medium, and electronic device. Specifically, the noise-immune quantum gate design apparatus can be integrated into an electronic device, which can be a server or a terminal, etc. The terminal can include mobile phones, wearable smart devices, tablets, laptops, and personal computers (PCs), etc., and other computer and auxiliary devices. The server can be a single server or a server cluster composed of multiple servers, and can be a physical server or a virtual server.
[0029] For example, such as Figure 1As shown, the electronic device can acquire the gauge information of the target quantum gate and the physical noise model of the target quantum system; based on the physical noise model, it performs Lie algebra symmetry analysis on the total Hamiltonian of the target quantum system to generate a symmetry-protected subspace, which is immune to the noise channels of the physical noise model; based on the gauge information, it synthesizes a quantum control pulse sequence through geometric optimization on the symmetric manifold corresponding to the symmetry-protected subspace; based on the mathematical properties of the symmetry-protected subspace, it verifies the theoretical fidelity lower bound of the quantum gate realized by the quantum control pulse sequence; when the theoretical fidelity lower bound meets the preset conditions, it outputs the theoretical fidelity lower bound and the quantum control pulse sequence.
[0030] The technical solutions shown in this application will be described in detail below through specific embodiments. It should be noted that the order of description of the following embodiments is not intended to limit the priority of the embodiments.
[0031] Please see Figure 2 , Figure 2 This is a flowchart illustrating the noise-immune quantum gate design method provided in an embodiment of this application. The specific flow of the noise-immune quantum gate design method is as follows: 101. Obtain the gauge information of the target quantum gate and the physical noise model of the target quantum system.
[0032] The specification information may include gate type and target, target evolution operator, performance requirements and gate operation time constraints.
[0033] This physical noise model is a mathematical abstract description of the main noise sources that a target quantum system may encounter in actual operation. This physical noise model includes, but is not limited to, the following two types: Decoherence noise: caused by the coupling between the quantum system and its environment, such as the process of energy relaxation and the process of phase decoherence.
[0034] Control error noise: caused by the non-ideality of the control system, such as amplitude deviation of control pulses, frequency detuning, and pulse timing jitter.
[0035] In the embodiments of this application, the physical noise model can be obtained based on calibration measurement data of a specific quantum hardware platform, or based on typical noise parameters of the platform's physical principles.
[0036] 102. Based on the physical noise model, perform Lie algebra symmetry analysis on the total Hamiltonian of the target quantum system to generate a symmetry-protected subspace. The symmetry-protected subspace is immune to the noise channels of the physical noise model.
[0037] In this embodiment, step 102 may include the following steps: 1021. Construct the total Hamiltonian based on the physical noise model and the target quantum system.
[0038] In some embodiments, the main noise channels in the physical noise model can be characterized as perturbation Hamiltonians; the control Hamiltonian of the target quantum system can be obtained; and the perturbation Hamiltonian and the control Hamiltonian can be combined into a total Hamiltonian.
[0039] Specifically, firstly, the main noise channels in the physical noise model, such as the dominant decoherence mode or control error, can be characterized as one or more perturbation Hamiltonians. Then, the control Hamiltonian of the target quantum system under ideal control is obtained, the form of which depends on the specific physical platform (e.g., the driving Hamiltonian of a superconducting quantum bit). Finally, the two are combined to construct the total Hamiltonian.
[0040] The perturbation Hamiltonian can be considered as a static perturbation that is independent of time or changes slowly, representing the average or worst-case effect of noise.
[0041] 1022. Determine the dynamic Lie algebra corresponding to the total Hamiltonian.
[0042] Understandably, the evolution of a quantum system is determined by the Hamiltonian, and all possible evolution operators can form a Lie group. The Lie algebra corresponding to this Lie group, namely the dynamical Lie algebra, can be spanned by all Hamiltonians (total Hamiltonians) accessible to the quantum system under ideal control.
[0043] 1023. Determine the symmetric protected subspace based on dynamic Lie algebra.
[0044] Specifically, in the dynamic Lie algebra, the subalgebra that commutes with the perturbation Hamiltonian can be determined; the subspace generated by the subalgebra is defined as the symmetric protected subspace.
[0045] Specifically, the step "in the dynamic Lie algebra, determine the subalgebra that commutes with the perturbation Hamiltonian" can be: calculating the commutators of all generators (a set of basis vectors) of the dynamic Lie algebra with the perturbation Hamiltonian; selecting the set of generators that satisfy the condition that the commutator is zero or that the commutator still belongs to the space spanned by the perturbation itself; and the subalgebra of the Lie algebra generated by the selected set of generators that commutes with the perturbation Hamiltonian.
[0046] In this embodiment, the Lie group corresponding to the subalgebra acts on the Hilbert state space of the system, defining an invariant subspace, namely the symmetry-protected subspace. Within this symmetry-protected subspace, any evolution described by the elements of the subalgebra commutes with noise perturbations, meaning that noise will not push the system state out of this symmetry-protected subspace, thus achieving inherent immunity to specific noise channels. Geometrically, this symmetry-protected subspace corresponds to a symmetric manifold.
[0047] 103. Based on normative information, quantum control pulse sequences are synthesized through geometric optimization on the symmetric manifold corresponding to the symmetric protected subspace.
[0048] In this embodiment, step 103 may include the following steps: 1031. Based on the specification information, determine the target evolution operator of the target quantum gate.
[0049] Specifically, the target evolution operator of the target quantum gate can be extracted directly from the canonical information.
[0050] 1032. Construct a geometric optimization model with the quantum evolution operator realized on a symmetric manifold approximating the target evolution operator as the objective function.
[0051] Understandably, this geometric optimization model aims to make the final evolved operator as close as possible to the target evolved operator (usually measured by fidelity), and imposes a key constraint: the instantaneous state throughout the evolution process must always remain on a symmetric manifold to ensure the evolution path is immune to noise.
[0052] 1033. In the Riemann space formed by symmetric manifolds, the geometric optimization model is solved iteratively to obtain the quantum control pulse sequence.
[0053] Within the Riemann space formed by symmetric manifolds, a geometric optimization algorithm can be used to iteratively solve the geometric optimization model, thereby obtaining a quantum control pulse sequence. This geometric optimization algorithm can be either the gradient descent method or the conjugate gradient method based on Riemann manifolds.
[0054] In each iteration, the geometric optimization algorithm calculates the gradient direction of the objective function on the manifold (Riemann gradient) and moves along this gradient direction on the symmetric manifold (usually along a geodesic or approximate geodesic), thereby updating the control pulse parameters while ensuring that intermediate evolutions do not deviate from the symmetric manifold. Finally, when the iterative solution converges, it outputs a set of optimal quantum control pulse sequences, which drive the system to complete the required gate operations along the symmetric manifold.
[0055] The convergence conditions for iterative solutions can be: the change in the objective function value between two consecutive iterations is less than the first threshold; the norm of the Riemann gradient is less than the second threshold; the fidelity of the realized quantum gate reaches or exceeds the third threshold; or the number of iterations reaches the maximum allowable value.
[0056] 104. Based on the mathematical properties of symmetry-protected subspaces, verify the theoretical fidelity lower limit of quantum gates realized by quantum control pulse sequences.
[0057] This embodiment can provide a mathematical proof of the reliability of quantum control pulse sequences, rather than relying solely on numerical simulations. In practical implementation, the upper limit of the influence of noise on evolution fidelity can be formally analyzed based on the mathematical property of the symmetry-protected subspace and its commutation relationship with noise perturbations.
[0058] Understandably, since the evolution is strictly constrained within a symmetric protected subspace that commutes with the noise, the noise effect is limited to producing a global phase within this symmetric protected subspace or an independent transformation within an invariant subspace, without causing the state to deviate from the ideal path. Through rigorous mathematical derivation (e.g., using perturbation theory and Lie group representation theory), it can be calculated that under the considered physical noise model, regardless of the specific instantaneous realization of the noise, the final gate fidelity will necessarily be no less than a certain value. This value is the theoretical fidelity lower bound. This verification process provides a deterministic performance guarantee beyond statistical simulation.
[0059] 105. When the theoretical fidelity lower limit meets the preset conditions, output the theoretical fidelity lower limit and the quantum control pulse sequence.
[0060] Among them, the preset conditions are usually set in advance by design requirements, such as requiring the theoretical fidelity lower limit to be higher than a certain application threshold (such as 99.9%), or to be better than the fidelity that traditional methods can achieve under the same noise model.
[0061] In practice, the theoretical fidelity lower limit can be compared with this preset condition. If the condition is met, the design is considered successful. Subsequently, the theoretical fidelity lower limit and the quantum control pulse sequence can be output.
[0062] The verified theoretical fidelity lower bound serves as mathematical proof of the robustness of this gate operation. In practical applications, the output quantum control pulse sequence can be directly used to drive the corresponding quantum hardware, executing high-fidelity quantum gate operations with inherent noise immunity.
[0063] In the embodiments of this application, the noise-immune quantum gate design method is platform-independent and applicable to various quantum computing physics implementation platforms, including superconducting qubits, ion traps, solid-state spin, and photonic quantum computing.
[0064] In summary, the noise-immune quantum gate design method provided in this application includes obtaining the gauge information of the target quantum gate and the physical noise model of the target quantum system; performing Lie algebra symmetry analysis on the total Hamiltonian of the target quantum system according to the physical noise model to generate a symmetry-protected subspace, which is immune to the noise channels of the physical noise model; synthesizing a quantum control pulse sequence through geometric optimization on the symmetric manifold corresponding to the symmetry-protected subspace based on the gauge information; verifying the theoretical fidelity lower bound of the quantum gate realized by the quantum control pulse sequence based on the mathematical properties of the symmetry-protected subspace; and outputting the theoretical fidelity lower bound and the quantum control pulse sequence when the theoretical fidelity lower bound meets the preset conditions. This application embodiment can improve the computational efficiency of quantum computing. By performing Lie algebra symmetry analysis on the total Hamiltonian to generate a symmetry-protected subspace with inherent immunity to specific noise channels, the evolution of quantum states naturally avoids the influence of major noise, without relying on an external error correction layer. Next, on the symmetric manifold corresponding to the symmetric protected subspace, a quantum control pulse sequence is synthesized through geometric optimization, integrating noise constraints with gate implementation. This ensures that the evolution path always lies on the symmetric manifold, thereby significantly reducing the stringent requirements for pulse control precision while achieving a high-fidelity target quantum gate. It also reduces the complexity and time overhead introduced by adding an extra control layer in traditional methods, thus improving the computational efficiency of quantum computing.
[0065] To facilitate better implementation of the noise-immune quantum gate design method provided in this application, this application also provides a noise-immune quantum gate design apparatus. The meanings of the terms used are the same as in the noise-immune quantum gate design method described above, and specific implementation details can be found in the descriptions within the method embodiments.
[0066] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of the noise-immune quantum gate design device provided in an embodiment of this application. The noise-immune quantum gate design device may include an acquisition unit 201, an analysis unit 202, a synthesis unit 203, an authentication unit 204, and an output unit 205. Acquisition unit 201 is used to acquire the gauge information of the target quantum gate and the physical noise model of the target quantum system; Analysis unit 202 is used to perform Lie algebra symmetry analysis on the total Hamiltonian of the target quantum system according to the physical noise model, so as to generate a symmetry-protected subspace that is immune to the noise channel of the physical noise model. Synthesis unit 203 is used to synthesize quantum control pulse sequences through geometric optimization on the symmetric manifold corresponding to the symmetric protected subspace based on gauge information; The authentication unit 204 is used to authenticate the theoretical fidelity lower bound of the quantum gate realized by the quantum control pulse sequence based on the mathematical properties of the symmetry-protected subspace. Output unit 205 is used to output the theoretical fidelity lower limit and the quantum control pulse sequence when the theoretical fidelity lower limit meets the preset conditions.
[0067] For specific implementation methods of each of the above units, please refer to the embodiments of the noise-immune quantum gate design method described above, which will not be repeated here.
[0068] In summary, the noise-immune quantum gate design device provided in this application embodiment can acquire the gauge information of the target quantum gate and the physical noise model of the target quantum system through the acquisition unit 201; the analysis unit 202 performs Lie algebra symmetry analysis on the total Hamiltonian of the target quantum system according to the physical noise model to generate a symmetry-protected subspace, which is immune to the noise channels of the physical noise model; the synthesis unit 203 synthesizes a quantum control pulse sequence through geometric optimization on the symmetric manifold corresponding to the symmetry-protected subspace based on the gauge information; the authentication unit 204 authenticates the theoretical fidelity lower bound of the quantum gate realized by the quantum control pulse sequence based on the mathematical properties of the symmetry-protected subspace; and the output unit 205 outputs the theoretical fidelity lower bound and the quantum control pulse sequence when the theoretical fidelity lower bound meets the preset conditions. This application embodiment generates a symmetry-protected subspace with inherent immunity to specific noise channels by performing Lie algebra symmetry analysis on the total Hamiltonian, which in principle allows the evolution of the quantum state to naturally avoid the influence of major noise without relying on an external error correction layer. Next, on the symmetric manifold corresponding to the symmetric protected subspace, a quantum control pulse sequence is synthesized through geometric optimization, integrating noise constraints with gate implementation. This ensures that the evolution path always lies on the symmetric manifold, thereby significantly reducing the stringent requirements for pulse control precision while achieving a high-fidelity target quantum gate. It also reduces the complexity and time overhead introduced by adding an extra control layer in traditional methods, thus improving the computational efficiency of quantum computing.
[0069] This application also provides an electronic device that may integrate the noise-immune quantum gate design device of this application embodiment, such as... Figure 4 As shown, it illustrates a structural schematic diagram of the electronic device involved in the embodiments of this application, specifically: The electronic device may include components such as a processor 301 with one or more processing cores and a memory 302 with one or more computer-readable storage media. Those skilled in the art will understand that... Figure 4 The electronic device structure shown does not constitute a limitation on the electronic device and may include more or fewer components than shown, or combine certain components, or have different component arrangements. Wherein: The processor 301 is the control center of the electronic device. It connects various parts of the electronic device via various interfaces and lines. By running or executing software programs stored in the memory 302 and / or this application, and by calling data stored in the memory 302, it performs various functions and processes data, thereby providing overall monitoring of the electronic device. Optionally, the processor 301 may include one or more processing cores; preferably, the processor 301 may integrate an application processor and a modem processor, wherein the application processor mainly handles the operation of the storage medium, user interface, and application programs, while the modem processor mainly handles wireless communication. It is understood that the modem processor may not be integrated into the processor 301.
[0070] The memory 302 can be used to store software programs and this application. The processor 301 executes various functional applications and data processing by running the software programs and this application stored in the memory 302. The memory 302 may mainly include a program storage area and a data storage area. The program storage area may store applications required for operating the storage medium and at least one function; the data storage area may store data created based on the use of the electronic device. In addition, the memory 302 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device. Accordingly, the memory 302 may also include a memory controller to provide the processor 301 with access to the memory 302.
[0071] Although not shown, the electronic device may also include a display unit, an input unit, and a power supply, etc., which will not be described in detail here. Specifically, in this embodiment, the processor 301 in the electronic device loads the executable files corresponding to the processes of one or more application programs into the memory 302 according to the following instructions, and the processor 301 runs the application programs stored in the memory 302 to realize various functions, as follows: Obtain the gauge information of the target quantum gate and the physical noise model of the target quantum system; Based on the physical noise model, Lie algebra symmetry analysis is performed on the total Hamiltonian of the target quantum system to generate a symmetry-protected subspace. The symmetry-protected subspace is immune to the noise channels of the physical noise model. Based on canonical information, quantum control pulse sequences are synthesized through geometric optimization on the symmetric manifold corresponding to the symmetric protected subspace; Based on the mathematical properties of symmetry-protected subspaces, the theoretical fidelity lower bound of quantum gates realized by quantum-controlled pulse sequences is verified. When the theoretical fidelity lower limit meets the preset conditions, the theoretical fidelity lower limit and the quantum control pulse sequence are output.
[0072] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be performed by instructions, or by instructions controlling related hardware. These instructions can be stored in a computer-readable storage medium and loaded and executed by a processor.
[0073] Therefore, embodiments of this application provide a storage medium storing a plurality of instructions that can be loaded by a processor to execute steps in any of the methods provided in embodiments of this application. For example, the instructions can execute the following steps: Obtain the gauge information of the target quantum gate and the physical noise model of the target quantum system; Based on the physical noise model, Lie algebra symmetry analysis is performed on the total Hamiltonian of the target quantum system to generate a symmetry-protected subspace. The symmetry-protected subspace is immune to the noise channels of the physical noise model. Based on canonical information, quantum control pulse sequences are synthesized through geometric optimization on the symmetric manifold corresponding to the symmetric protected subspace; Based on the mathematical properties of symmetry-protected subspaces, the theoretical fidelity lower bound of quantum gates realized by quantum-controlled pulse sequences is verified. When the theoretical fidelity lower limit meets the preset conditions, the theoretical fidelity lower limit and the quantum control pulse sequence are output.
[0074] For details on the implementation of each of the above operations, please refer to the previous examples, which will not be repeated here.
[0075] The storage medium may include: read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.
[0076] Since the instructions stored in the storage medium can execute the steps of any method provided in the embodiments of this application, the beneficial effects that any method provided in the embodiments of this application can achieve can be realized. For details, please refer to the previous embodiments, which will not be repeated here.
[0077] The noise-immune quantum gate design method, device, storage medium, and electronic device provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A method for designing noise-immune quantum gates, characterized in that, include: Obtain the gauge information of the target quantum gate and the physical noise model of the target quantum system; Based on the physical noise model, a Lie algebra symmetry analysis is performed on the total Hamiltonian of the target quantum system to generate a symmetry-protected subspace, which is immune to the noise channels of the physical noise model. Based on the aforementioned specification information, quantum control pulse sequences are synthesized through geometric optimization on the symmetric manifold corresponding to the symmetric protected subspace. Based on the mathematical properties of the symmetry-protected subspace, the theoretical fidelity lower limit of the quantum gate realized by the quantum control pulse sequence is verified; When the theoretical fidelity lower limit meets the preset conditions, the theoretical fidelity lower limit and the quantum control pulse sequence are output.
2. The noise-immune quantum gate design method as described in claim 1, characterized in that, The step of performing Lie algebra symmetry analysis on the total Hamiltonian of the target quantum system based on the physical noise model to generate a symmetry-protected subspace includes: Based on the physical noise model and the target quantum system, construct the total Hamiltonian; Determine the dynamic Lie algebra corresponding to the total Hamiltonian; The symmetric protected subspace is determined based on the aforementioned dynamic Lie algebra.
3. The noise-immune quantum gate design method as described in claim 2, characterized in that, The construction of the total Hamiltonian based on the physical noise model and the target quantum system includes: The main noise channels in the physical noise model are characterized as perturbation Hamiltonians. Obtain the control Hamiltonian of the target quantum system; The perturbation Hamiltonian and the control Hamiltonian are combined into a total Hamiltonian.
4. The noise-immune quantum gate design method as described in claim 3, characterized in that, The determination of the symmetry-protected subspace based on the dynamic Lie algebra includes: In the dynamic Lie algebra, a subalgebra that commutes with the perturbation Hamiltonian is determined; The subspace generated by the subalgebra is defined as a symmetric protected subspace.
5. The noise-immune quantum gate design method as described in claim 4, characterized in that, In the dynamic Lie algebra, determining the subalgebra that commutes with the perturbation Hamiltonian includes: Calculate all generators of the dynamic Lie algebra and the commutators of the perturbation Hamiltonian; Select a set of generators that satisfy either that the commutator is zero or that the commutator belongs to the perturbation Hamiltonian itself; The subalgebra of the Lie algebra generated from the selected set of generators that commutes with the perturbation Hamiltonian.
6. The noise-immune quantum gate design method as described in claim 1, characterized in that, The process of synthesizing quantum-controlled pulse sequences on the symmetric manifold corresponding to the symmetric protected subspace based on the aforementioned canonical information includes: Based on the aforementioned specification information, the target evolution operator of the target quantum gate is determined; A geometric optimization model is constructed with the quantum evolution operator realized on the symmetric manifold approximating the target evolution operator as the objective function; Within the Riemann space formed by the symmetric manifold, the geometric optimization model is iteratively solved to obtain a quantum control pulse sequence.
7. The noise-immune quantum gate design method as described in claims 1-6, characterized in that, The noise-immune quantum gate design method is applicable to various quantum computing physics implementation platforms, including superconducting qubits, ion traps, solid-state spin, and photonic qubits.
8. A noise-immune quantum gate design device, characterized in that, include: The acquisition unit is used to acquire the gauge information of the target quantum gate and the physical noise model of the target quantum system; The analysis unit is used to perform Lie algebra symmetry analysis on the total Hamiltonian of the target quantum system according to the physical noise model, so as to generate a symmetry-protected subspace, which is immune to the noise channels of the physical noise model. A synthesis unit is used to synthesize a quantum-controlled pulse sequence on the symmetric manifold corresponding to the symmetric protected subspace through geometric optimization based on the canonical information. The authentication unit is used to authenticate the theoretical fidelity lower bound of the quantum gate realized by the quantum control pulse sequence based on the mathematical properties of the symmetry protected subspace. The output unit is used to output the theoretical fidelity lower limit and the quantum control pulse sequence when the theoretical fidelity lower limit meets the preset conditions.
9. A storage medium, characterized in that, The storage medium stores multiple instructions adapted for loading by a processor to execute the noise-immune quantum gate design method according to any one of claims 1-7.
10. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the noise-immune quantum gate design method as described in any one of claims 1-7.