A method and apparatus for molecular dynamics simulation based on quantum computing

Abstract

A quantum computing-based molecular dynamics simulation method and device, wherein the quantum computing-based molecular dynamics simulation method comprises: preparing a first quantum state of atomic nuclei represented as a wave packet, and determining an evolution time, the evolution time comprising a plurality of evolution stages; according to the first quantum state, sequentially performing a plurality of evolution processes corresponding to the plurality of evolution stages to obtain a second quantum state after evolution, the plurality of evolution stages comprising an evolution stage, and performing the evolution process corresponding to the evolution stage comprises: before the evolution stage, performing a plurality of measurements on a third quantum state of the atomic nuclei before the evolution stage to obtain a plurality of target positions of the atomic nuclei, determining a plurality of potential energy values corresponding to the plurality of target positions according to the plurality of target positions, and constructing a plurality of first quantum gates corresponding to the plurality of potential energy values; determining a second quantum gate according to the kinetic energy of the atomic nuclei; and obtaining a fourth quantum state according to the third quantum state, the plurality of first quantum gates, and the second quantum gate.

Description

Technical Field

[0001] The present invention relates to the field of quantum chemistry, and in particular to a molecular dynamics simulation method and device based on quantum computing. Background Art

[0002] Molecular dynamics simulation is an important computational chemistry method used to study the structure, dynamic behavior, and interactions of molecules under different conditions. By simulating the movement and interactions of molecules, we can gain a deeper understanding of the mechanisms of chemical reactions, the structure and function of biomolecules, and the properties of materials. This method has a wide range of applications in drug design, materials science, biophysics, and other fields. However, traditional molecular dynamics simulations often face the challenges of high computational complexity and long time consumption when dealing with large-scale molecular systems. In particular, when simulating large molecular systems or dynamic processes on long time scales, traditional classical computational methods may encounter problems such as insufficient computing resources and insufficient accuracy.

[0003] Therefore, a molecular dynamics simulation method and device based on quantum computing are needed. Summary of the Invention

[0004] The purpose of this invention is to provide a quantum computing-based molecular dynamics simulation method and apparatus. By combining the classical and quantum descriptions of atomic nuclei, this paper proposes a novel molecular dynamics quantum computing simulation method that treats nuclei as wave packets. This method reduces computational complexity while taking into account the quantum effects of atomic nuclei. It also reduces the depth of quantum circuits and the requirements for quantum hardware, thus conserving quantum device resources.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a molecular dynamics simulation method based on quantum computing, comprising:

[0006] preparing a first quantum state of a target atomic nucleus represented as a wave packet, and determining a target evolution time, wherein the target evolution time includes a plurality of evolution stages;

[0007] According to the first quantum state, multiple evolutionary processes corresponding to multiple evolutionary stages are sequentially performed to obtain an evolved second quantum state, wherein the multiple evolutionary stages include a target evolutionary stage, and performing the evolutionary processes corresponding to the target evolutionary stage includes:

[0008] Before the target evolution stage, the third quantum state of the target atomic nucleus before the target evolution stage is measured multiple times to obtain multiple target positions of the atomic nucleus, and multiple potential energy values ​​corresponding to the multiple target positions are determined based on the multiple target positions and a preset; multiple first quantum gates corresponding to the multiple potential energy values ​​are constructed, and a second quantum gate is determined based on the kinetic energy of the target atomic nucleus;

[0009] A fourth quantum state is obtained according to the third quantum state, the plurality of first quantum gates and the second quantum gate.

[0010] Specifically, determining a plurality of potential energy values ​​corresponding to the plurality of target positions according to the plurality of target positions includes: determining a plurality of potential energy values ​​corresponding to the plurality of target positions by a variational quantum eigenvalue solver according to the plurality of target positions.

[0011] Specifically, the wave packet includes a wave function corresponding to a predetermined position.

[0012] Preferably, the multiple first quantum gates corresponding to the multiple potential energy values ​​are expressed as: ,in, is the projection operator, K is the serial number of the first quantum gate, is the time interval, is the potential energy value, is the imaginary unit, is a natural constant.

[0013] Specifically, the second quantum gate is expressed as ,in, is the imaginary unit, is a natural constant, is the time interval, is the nuclear kinetic energy operator.

[0014] Specifically, obtaining the fourth quantum state according to the third quantum state, the multiple first quantum gates and the second quantum gate includes: sequentially applying the second quantum gate and the multiple first quantum gates to the third quantum state to obtain the fourth quantum state.

[0015] In a second aspect, the present invention provides a molecular dynamics simulation device based on quantum computing, comprising:

[0016] a determining unit configured to prepare a first quantum state of a target atomic nucleus represented as a wave packet, and determine a target evolution time, wherein the target evolution time includes a plurality of evolution stages;

[0017] The processing unit is configured to, based on the first quantum state, sequentially perform multiple evolutionary processes corresponding to multiple evolutionary stages to obtain an evolved second quantum state, wherein the multiple evolutionary stages include a target evolutionary stage, and performing the evolutionary processes corresponding to the target evolutionary stage includes:

[0018] Before the target evolution stage, a third quantum state of the target atomic nucleus before the target evolution stage is measured multiple times to obtain multiple target positions of the atomic nucleus, and multiple potential energy values ​​corresponding to the multiple target positions are determined based on the multiple target positions; multiple first quantum gates corresponding to the multiple potential energy values ​​are constructed, and a second quantum gate is determined based on the kinetic energy of the target atomic nucleus;

[0019] The output unit is configured to obtain a fourth quantum state according to the third quantum state, the plurality of first quantum gates and the second quantum gate.

[0020] In a third aspect, the present invention provides a computer-readable storage medium storing a computer program. When the computer program runs on an electronic device, the electronic device executes the method described in the first aspect.

[0021] In a fourth aspect, the present invention provides an electronic device comprising: a processor, a memory, and computer program instructions stored in the memory and executable on the processor, wherein the processor is used to implement the method described in the first aspect when executing the computer program instructions.

[0022] Compared with the existing technology, the present invention has the following advantages: treating the nuclear wave function as a wave packet can effectively reduce the computational complexity, is easier to implement on the existing quantum computing platform, retains certain quantum properties, and can handle more complex molecular structures and larger system scales. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A flowchart of a molecular dynamics simulation method based on quantum computing provided by an embodiment of the present invention;

[0024] Figure 2 A quantum circuit diagram of a molecular dynamics simulation method based on quantum computing provided by an embodiment of the present invention;

[0025] Figure 3 A structural diagram of a molecular dynamics simulation device based on quantum computing provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments.

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described below with reference to the accompanying drawings. It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0028] In the description of the embodiments of the present invention, words such as "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of the present invention should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0029] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly identifying the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. The terms "include," "comprising," "having," and their variations all mean "including but not limited to," unless otherwise specifically emphasized.

[0030] One of the goals of molecular dynamics simulations is to describe and understand the motion of atomic nuclei within molecules and their interactions, thereby inferring their structure, properties, and behavior. In molecular dynamics simulations, the motion of atomic nuclei evolves within a given potential energy surface (typically determined by the molecular structure and electronic states). Therefore, one of the keys to molecular dynamics simulations is to accurately describe the motion of atomic nuclei within a given potential energy field.

[0031] Traditional molecular dynamics simulations use a semiclassical approach, combining classical mechanics and quantum mechanics. In this approach, the motion of the nucleus evolves according to classical force fields, while the electronic structure is described by quantum mechanics. The specific process is as follows: First, using the Born-Oppenheimer approximation, the nucleus is considered stationary to obtain the electron Hamiltonian. This electronic Hamiltonian is then used to solve for electron orbitals, yielding the density distribution of all electrons in the molecule. This electron density distribution is then used to approximate the interaction between the electron and the nucleus, i.e., the equivalent potential energy surface of the nucleus. Finally, the nucleus is treated as a classical particle, and its motion within the potential energy surface is solved using Newton's equations.

[0032] Although the semiclassical method separates the interactions between the nucleus and the electrons, achieving a balance between computational efficiency and accuracy, its essence is still to describe the motion of the nucleus using a classical force field. Therefore, the semiclassical method cannot accurately simulate the quantum effects of the nucleus, such as zero-point vibrations, quantum fluctuations and other phenomena. In some cases, especially at low temperatures or high energy environments, the quantum effects of the nucleus may have a significant impact on the molecular dynamics process, and the semiclassical method cannot capture these effects, resulting in inaccurate simulation results. In addition, the classical force field in the semiclassical method is usually obtained based on empirical parameter fitting, and its accuracy and scope of application are limited by the parameter selection. Due to the different structures and properties of different molecular systems, parameter optimization or adjustment is often required for specific systems, which increases the uncertainty in the simulation process and limits the versatility and scope of application of the method.

[0033] With the development of quantum computing technology, more and more research is using quantum mechanics to simulate molecular dynamics. In quantum mechanics, both the nucleus and electrons are considered wave functions, whose evolution is described by the Schrödinger equation. Due to the wave-particle duality of quantum mechanics, quantum mechanics can more accurately describe the quantum behavior of the nucleus, including effects such as wave function coherence and quantum tunneling. The specific process is as follows: the overall quantum state of the nucleus and electrons at the initial moment is given. Based on the overall Hamiltonian, the state of the initial overall quantum state after time t is simulated. The electronic portion of the overall quantum state is traced to obtain the final quantum state of the nucleus.

[0034] While quantum mechanical methods offer greater accuracy and reliability by accounting for the full quantum effects of atomic nuclei and electrons, they often come with a high computational complexity, particularly when dealing with large-scale molecular systems. Since an exact expression for the equivalent potential energy surface of a nucleus is often unavailable, it acts as a black box, and each access only yields the potential energy value at a single spatial coordinate. Accurately simulating the quantum mechanical behavior of a nucleus typically requires potential energy values ​​at exponentially more spatial coordinates. Therefore, in practical applications, quantum mechanical methods often require significant computational resources and time, limiting their application in simulating large-scale molecular systems.

[0035] To overcome the shortcomings of existing technologies, a molecular dynamics simulation method based on quantum computing is proposed. By sampling the current quantum state of the nucleus multiple times, the wave function wave packet position is approximated. By simply calculating the value of the potential energy surface at these positions and ignoring the potential energy at other positions outside the wave packet, an approximate potential energy function with a polynomial number of calculations can be obtained. This approximate potential energy can simulate the rigorous evolution at the locations where the nucleus mainly appears, thus achieving a high degree of accuracy. It also retains the quantum mechanical representation of the nucleus and can simulate its quantum effects.

[0036] Figure 1 The flowchart of a molecular dynamics simulation method based on quantum computing provided by an embodiment of the present invention. Figure 1 As shown, the method comprises at least the following steps:

[0037] S101: preparing a first quantum state of a target atomic nucleus represented as a wave packet, and determining a target evolution time, wherein the target evolution time includes multiple evolution stages.

[0038] A wave packet is a wave composed of simple harmonic waves of different frequencies and wavenumbers (or wavelengths). Unlike simple harmonic waves, wave packets typically do not extend infinitely in space. Instead, they have a significant amplitude within a certain spatial region. Outside this region, the amplitude rapidly decays to zero, as if the wave is "confined" to a finite spatial range. Hence the name "wave packet." In one embodiment, the wave packet includes a wave function corresponding to a predetermined location.

[0039] For example, the state of the nucleus at the initial moment is selected. This state exhibits a wave packet form, i.e., it is primarily concentrated at a certain point. For example, a wave function at a predetermined specific location can be selected. A target evolution time T and a time interval Δt are set. Based on the selected target evolution time T and time interval Δt, the total number of evolution steps n = T / Δt can be calculated. In different specific examples, the wave function at the predetermined location can be a wave function at different specific locations, and this specification does not limit this.

[0040] S102: Based on the first quantum state, sequentially perform multiple evolutionary processes corresponding to multiple evolutionary stages to obtain an evolved second quantum state, wherein the multiple evolutionary stages include a target evolutionary stage, and performing the evolutionary processes corresponding to the target evolutionary stage includes:

[0041] Before the target evolution stage, the third quantum state of the target atomic nucleus before the target evolution stage is measured multiple times to obtain multiple target positions of the atomic nucleus, and multiple potential energy values ​​corresponding to the multiple target positions are determined based on the multiple target positions and a preset potential energy determination module; multiple first quantum gates corresponding to the multiple potential energy values ​​are constructed, and the second quantum gate is determined according to the kinetic energy of the target atomic nucleus.

[0042] In different embodiments, the specific method of determining the corresponding potential energy value according to the target position may be different. In a specific embodiment, a variational quantum eigenvalue solver can be used to determine multiple potential energy values ​​corresponding to the nucleus at multiple positions.

[0043] In one embodiment, the multiple first quantum gates corresponding to the multiple potential energy values ​​can be expressed as: ,in, is the projection operator, K is the serial number of the first quantum gate, is the time interval, is the potential energy value, is the imaginary unit, is a natural constant.

[0044] In one embodiment, the second quantum gate can be expressed as ,in, is the imaginary unit, is a natural constant, is the time interval, is the nuclear kinetic energy operator.

[0045] In one embodiment, obtaining a fourth quantum state according to the third quantum state, the plurality of first quantum gates and the second quantum gate includes: applying the second quantum gate to the third quantum state, and then sequentially applying the plurality of first quantum gates to obtain the fourth quantum state.

[0046] For example, starting from the initial moment, before the start of each short time interval, the quantum state of the atomic nucleus is measured and sampled multiple times to obtain the possible positions of several atomic nuclei. For each sampled position, a module for calculating the potential energy surface is called. This module can represent a computational model. For example, the Hartree-Fock (HF) method or coupled-cluster singles and doubles (Coupled-Cluster Singles and Doubles) method can be implemented on a quantum computer through a variational quantum eigenvalue solver (VQE). The potential energy values ​​at these positions are obtained by inputting the nucleus position information into the module. , and construct the corresponding gate in the quantum circuit ,in, is the projection operator, K is the serial number of the first quantum gate, is the time interval, is the potential energy value, is the imaginary unit, is a natural constant. Figure 2 A quantum circuit diagram of a molecular dynamics simulation method based on quantum computing provided by an embodiment of the present invention, such as Figure 2 As shown, the state of the nucleus is represented by the wave function Description, this is the starting point of the whole process, this wave function contains the atomic nucleus at a specific moment All the information of; According to the kinetic energy of the target nucleus, the second quantum gate is determined, where the second quantum gate can be expressed as ,in, is the imaginary unit, is a natural constant, is the time interval, is the nuclear kinetic energy operator, and multiple first quantum gates are ,in, is the projection operator, K is the serial number of the first quantum gate, is the time interval, is the potential energy value, is the imaginary unit, is a natural constant.

[0047] S103: Obtain a fourth quantum state according to the third quantum state, the plurality of first quantum gates, and the second quantum gate.

[0048] For example, the time evolution is described by the Schrödinger equation, and the wave function is evolved through quantum circuits to obtain the next moment The quantum state of the nucleus This new quantum state can be used as the initial state for the next round of simulation. By repeating this process, the evolution of the nuclear quantum state over time can be simulated.

[0049] According to yet another embodiment, a molecular dynamics simulation device based on quantum computing is provided. Figure 3 The structure diagram of the molecular dynamics simulation device based on quantum computing provided by the embodiment of the present invention is as follows: Figure 3 As shown, the device 300 includes:

[0050] The determining unit 301 is configured to prepare a first quantum state of a target atomic nucleus represented as a wave packet, and determine a target evolution time, wherein the target evolution time includes a plurality of evolution stages;

[0051] The processing unit 302 is configured to sequentially perform multiple evolutionary processes corresponding to multiple evolutionary stages based on the first quantum state to obtain an evolved second quantum state, wherein the multiple evolutionary stages include a target evolutionary stage, and performing the evolutionary processes corresponding to the target evolutionary stage includes:

[0052] Before the target evolution stage, a third quantum state of the target atomic nucleus before the target evolution stage is measured multiple times to obtain multiple target positions of the atomic nucleus, and multiple potential energy values ​​corresponding to the multiple target positions are determined based on the multiple target positions; multiple first quantum gates corresponding to the multiple potential energy values ​​are constructed, and a second quantum gate is determined based on the kinetic energy of the target atomic nucleus;

[0053] The output unit 303 is configured to obtain a fourth quantum state according to the third quantum state, the plurality of first quantum gates, and the second quantum gate.

[0054] It is understood that the method steps in the embodiments of the present invention can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, removable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and storage medium can be located in an ASIC.

[0055] In the above embodiments, all or part of the embodiments can be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in accordance with the embodiments of the present invention are fully or partially generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted via the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer, or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

[0056] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A molecular dynamics simulation method based on quantum computing, comprising: preparing a first quantum state of a target atomic nucleus represented as a wave packet, and determining a target evolution time, wherein the target evolution time includes a plurality of evolution stages; According to the first quantum state, multiple evolutionary processes corresponding to multiple evolutionary stages are sequentially performed to obtain an evolved second quantum state, wherein the multiple evolutionary stages include a target evolutionary stage, and performing the evolutionary processes corresponding to the target evolutionary stage includes: Before the target evolution stage, the third quantum state of the target atomic nucleus before the target evolution stage is measured multiple times to obtain multiple target positions of the atomic nucleus, and multiple potential energy values ​​corresponding to the multiple target positions are determined based on the multiple target positions; multiple first quantum gates corresponding to the multiple potential energy values ​​are constructed, and a second quantum gate is determined based on the kinetic energy of the target atomic nucleus; the multiple first quantum gates corresponding to the multiple potential energy values ​​are expressed as: ,in, is the projection operator, K is the serial number of the first quantum gate, is the time interval, is the potential energy value, is the imaginary unit, is a natural constant; A fourth quantum state is obtained according to the third quantum state, the plurality of first quantum gates and the second quantum gate.

2. The method according to claim 1, wherein Determining a plurality of potential energy values ​​corresponding to the plurality of target positions according to the plurality of target positions includes: determining a plurality of potential energy values ​​corresponding to the plurality of target positions by a variational quantum eigenvalue solver according to the plurality of target positions.

3. The method according to claim 1, wherein The wave packet includes a wave function corresponding to a predetermined position.

4. The method according to claim 1, wherein The second quantum gate is expressed as ,in, is the imaginary unit, is a natural constant, is the time interval, is the nuclear kinetic energy operator.

5. The method according to claim 1 , wherein obtaining a fourth quantum state according to the third quantum state, the plurality of first quantum gates, and the second quantum gate comprises: The second quantum gate and the plurality of first quantum gates are sequentially applied to the third quantum state to obtain a fourth quantum state.

6. A molecular dynamics simulation device based on quantum computing, comprising: a determining unit configured to prepare a first quantum state of a target atomic nucleus represented as a wave packet, and determine a target evolution time, wherein the target evolution time includes a plurality of evolution stages; The processing unit is configured to, based on the first quantum state, sequentially perform multiple evolutionary processes corresponding to multiple evolutionary stages to obtain an evolved second quantum state, wherein the multiple evolutionary stages include a target evolutionary stage, and performing the evolutionary processes corresponding to the target evolutionary stage includes: Before the target evolution stage, the third quantum state of the target atomic nucleus before the target evolution stage is measured multiple times to obtain multiple target positions of the atomic nucleus. Based on the multiple target positions, multiple potential energy values ​​corresponding to the multiple target positions are determined, and multiple first quantum gates corresponding to the multiple potential energy values ​​are constructed; based on the kinetic energy of the target atomic nucleus, a second quantum gate is determined; the multiple first quantum gates corresponding to the multiple potential energy values ​​are expressed as: ,in, is the projection operator, K is the serial number of the first quantum gate, is the time interval, is the potential energy value, is the imaginary unit, is a natural constant; and an output unit configured to obtain a fourth quantum state according to the third quantum state, the plurality of first quantum gates and the second quantum gate.

7. A computer-readable storage medium storing a computer program, wherein when the computer program is executed on an electronic device, the electronic device executes the method according to any one of claims 1 to 5.

8. An electronic device comprising: A processor, a memory, and computer program instructions stored in the memory and running on the processor, wherein the processor is used to implement the method according to any one of claims 1 to 5 when executing the computer program instructions.

Images