A method and device for simulating atomic nuclei based on quantum computing

Abstract

An embodiment of the present invention provides a method and device for simulating a nuclear nucleus based on quantum computing, the method comprising: determining a Hamiltonian operator corresponding to a nucleus in a nuclear shell model; setting a first quantum circuit according to the Hamiltonian operator; obtaining a first quantum state of the nucleus, and running the first quantum circuit according to the first quantum state to obtain a second quantum state, wherein the second quantum state is closer to the ground state of the nucleus than the first quantum state.

Description

Technical Field

[0001] The present invention relates to the fields of quantum computing and atomic nucleus simulation, and in particular to an atomic nucleus simulation method and device based on quantum computing. Background Art

[0002] The atomic nucleus is an important level of the subatomic material structure. Nuclear physics is a branch of the discipline that was established at the end of the 19th century to study the microscopic structure of matter. The release of nuclear energy can provide a considerable new energy source for human society. Nuclear physics is currently a field of science and technology with fierce international competition. The study of the structure of the atomic nucleus is of great significance.

[0003] Traditional methods of nuclear simulation based on classical computers and VQE quantum algorithms can achieve the purpose of obtaining the ground state and ground state energy of the nucleus. However, these methods are often too complex to calculate, especially for the simulation of heavy nuclei, which requires too many computing resources and is often difficult to implement in actual production scenarios.

[0004] Therefore, a new approach to nuclear simulation is needed. Summary of the invention

[0005] An embodiment of the present invention provides a method and device for nuclear simulation based on quantum computing. Compared with the nuclear simulation method based on classical computers, this method can significantly reduce the computational complexity in nuclear simulation, thereby greatly reducing the computing resources consumed by nuclear simulation.

[0006] An embodiment of the present invention provides a method for simulating atomic nuclei based on quantum computing, the method comprising:

[0007] Determine the Hamiltonian operator corresponding to the nucleus in the nuclear shell model;

[0008] According to the Hamiltonian operator, setting a first quantum circuit;

[0009] A first quantum state of the atomic nucleus is obtained, and a first quantum circuit is operated according to the first quantum state to obtain a second quantum state, wherein the second quantum state is closer to the ground state of the atomic nucleus than the first quantum state.

[0010] Preferably, the method further comprises measuring the expectation value of the Hamiltonian in the second quantum state to obtain the ground state energy of the nucleus.

[0011] Preferably, the first quantum state is obtained based on second quantization and Jordan-Wigner transformation.

[0012] Preferably, the first quantum state is a Hartree-Fock state.

[0013] Preferably, setting a first quantum circuit according to the Hamiltonian operator comprises:

[0014] Setting an auxiliary system and a working system, wherein the working system and the auxiliary system respectively include a number of bits;

[0015] Determine some basic computational eigenstates of the auxiliary system;

[0016] According to the Hamiltonian operator and a preset iteration step, a plurality of first weights respectively corresponding to the plurality of computational basic eigenstates and a plurality of unitary quantum gates respectively corresponding to the plurality of computational basic eigenstates are determined.

[0017] Preferably, the operating the first quantum circuit to obtain the second quantum state comprises:

[0018] The auxiliary system is prepared as a superposition state of the plurality of basic computing eigenstates, wherein the weights of the various basic computing eigenstates are the corresponding first weights;

[0019] preparing the working system to be in the first quantum state;

[0020] applying the plurality of unitary quantum gate operations to the working system according to the state of the auxiliary system;

[0021] Apply a Hardmard gate to each qubit in the auxiliary system;

[0022] The state of the auxiliary system is measured. When it is in the |0〉 state, the final quantum state of the working system is read to obtain the second quantum state.

[0023] Preferably, the unitary quantum gate is a Pauli gate.

[0024] In a second aspect, a nuclear simulation device based on quantum computing is provided, the device comprising:

[0025] A Hamiltonian acquisition unit is configured to determine a Hamiltonian operator corresponding to an atomic nucleus in an atomic nucleus shell model;

[0026] A quantum circuit setting unit is configured to set a first quantum circuit according to the Hamiltonian operator;

[0027] The quantum circuit execution unit is configured to obtain a first quantum state of the atomic nucleus, and according to the first quantum state, run the first quantum circuit to obtain a second quantum state, wherein the second quantum state is closer to the ground state of the atomic nucleus than the first quantum state.

[0028] According to a third aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed in a computer, the computer is caused to execute any of the methods described in the foregoing items.

[0029] In a fourth aspect, a computing device is provided, comprising a memory and a processor, wherein the memory stores executable code, and when the processor executes the executable code, any of the methods described above is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0031] Figure 1 A schematic diagram of the principle of a method for simulating atomic nuclei based on quantum computing provided by an embodiment of the present invention;

[0032] Figure 2 A flowchart of a method for simulating atomic nuclei based on quantum computing provided by an embodiment of the present invention;

[0033] Figure 3 A schematic diagram of a first quantum circuit provided by an embodiment of the present invention;

[0034] Figure 4 A structural diagram of a nuclear simulation device based on quantum computing provided by an embodiment of the present invention; DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] As mentioned above, nuclear simulation has important technical significance in both science and industry. At the level of nuclear degrees of freedom, the existing nuclear model can only partially explain the characteristics of the nucleus, and a unified microscopic model has not yet been established. The shell model is one of the more explanatory models of the nucleus. On the basis of the mean field approximation, it is compatible with different nuclear force models, thereby providing a more detailed description of the characteristics of the nucleus. In existing technologies, classical computers can be used to simulate the nucleus and the diagonalization method can be used to calculate the ground state energy. If the full Hamiltonian is used, the space complexity is O(2 2K ), the time complexity is O(2 6K), where K is the number of fermion single-particle states; if the reduced Hamiltonian is used, the space complexity is The time complexity is In other words, for the simulation of atomic nuclei, the simulation method of classical computers can be used, but the calculations are too complex and the resources consumed are too high, making it difficult to implement in actual generation scenarios.

[0037] In order to solve the above technical problems, an embodiment of the present invention provides a method for simulating atomic nuclei based on quantum computing. The basic idea of ​​the present invention is described below. Figure 1 The schematic diagram of the principle of a method for simulating atomic nuclei based on quantum computing provided by an embodiment of the present invention. Figure 1 As shown, first, the atomic nucleus Hamiltonian based on the shell model and the initial quantum state characterizing the initial state of the atomic nucleus (for example, the Hartree-Fock state) are quantized twice and converted into a quantum bit form. Then, according to the Hamiltonian in the form of quantum bits after the second quantization, a quantum circuit for solving the ground state and ground state energy of the atomic nucleus is constructed. Finally, the above quantum circuit is executed on the quantum processor, and the initial quantum state is evolved into a final quantum state after the quantum circuit, and the final quantum state obtained by this evolution is used as the initial quantum state of the next iterative evolution. After multiple iterative evolutions, the final final quantum state is measured to obtain the ground state and ground state energy of the atomic nucleus.

[0038] Figure 2 A flowchart of a method for simulating atomic nuclei based on quantum computing is provided in an embodiment of the present invention. Figure 2 As shown, the process of the method at least includes:

[0039] Step 21, determining the Hamiltonian operator corresponding to the nucleus in the nuclear shell model.

[0040] Usually, for nuclear simulation, the simulation object, that is, the target nucleus to be simulated, must be known in advance. If the target nucleus is clear, the number of protons and neutrons contained in the target nucleus is also clear. Therefore, in this step, the Hamiltonian of the nucleus can be determined based on the nuclear shell model and the number of protons and neutrons, and then based on the Hamiltonian, the Hamiltonian operator equivalent to the Hamiltonian in quantum computing can be further determined. Specifically, according to the atomic shell model, the nucleus is a relativistic quantum many-body system that includes electromagnetic interactions and strong interactions. In one embodiment, under the coordinate representation, the nucleon degree of freedom hierarchy, the nucleus The Hamiltonian can be expressed as:

[0041]

[0042] Where Z is the number of protons in the nucleus, A is the total number of nucleons in the nucleus (protons and neutrons are collectively referred to as nucleons), and N=AZ is the number of neutrons in the nucleus. p =938.3MeV / c 2 is the rest mass of a single proton, M n =939.6MeV / c 2 is the rest mass of a single neutron, e = 1.6 × 10 -19 C is the charge of the elementary charge, ∈0=8.8×10 -12 F / m is the dielectric constant of vacuum, and P is pi. is the proton kinetic energy term, is the neutron kinetic energy term, where and are the momentum of the i-th (1≤i≤Z) nucleon (proton) and the j-th (Z+1≤j≤A) nucleon (neutron), respectively. is the Coulomb interaction between protons, where is the Coulomb interaction potential energy between the i1th nucleon (proton) and the i2th nucleon (proton), and are the position vectors of the i1th and i2th nucleons (protons), Describes the strong interaction between nucleons. In one embodiment, under the mean field approximation of the nuclear shell model, the strong interaction between nucleons can be decomposed into a relatively strong mean field potential energy term and relatively weaker remaining interaction terms, where is the potential energy of the knth nucleon in the mean field, is the position vector of the knth nucleon, and w(kn1,kn2) is the residual interaction potential between nucleons kn1 and kn2. When only two-body interaction is considered, the residual interaction term can be written as Its specific expression is determined by the specific nuclear force model.

[0043] In one embodiment, the mean field potential energy term may specifically be:

[0044]

[0045] In formula (2), for convenience, In formula (1), so In formula (1), Among them, U c () is the Wood-Saxon potential well, r is The model, r0=1.27fm,a=0.67fm,V sl=-0.44U0, and are the spin angular momentum operator and orbital angular momentum operator of the particle (i.e. nucleon), and U0 is the depth of the mean field.

[0046] Since the protons and neutrons in the nucleus are all spin 1 / 2 fermions, protons and protons, and neutrons and neutrons are indistinguishable from a physical point of view. Usually, the nucleus can be described using coordinate representation, which numbers the particles, writes the wave function of each particle, and finally desymmetrizes to express the wave function of the entire nucleus. It can also be described using occupation number representation, which indicates the distribution of particle numbers in each single-particle state without distinguishing between particles. The two descriptions are mathematically equivalent, but using the second quantized occupation number representation is a more natural and especially computationally simpler way.

[0047] Therefore, in one embodiment, the nuclear Hamiltonian in coordinate representation can be converted to occupation number representation. That is, appropriate single-particle state sets are specified for protons and neutrons respectively. and (where ψ π,i represents the i-th single-particle state of the proton, ψ ν,j represents the jth single-particle state of the neutron, N π and N ν are the number of single-particle states of protons and neutrons respectively, and let N π =N ν =K, K is the number of the above-mentioned fermion single-particle states), protons and neutrons will be filled into these single-particle states respectively. Since protons and neutrons are both fermions, according to the Pauli exclusion principle, each single-particle state can only occupy one particle at most.

[0048] In one embodiment, the Hamiltonian of the second quantization of the nucleus can be obtained by the following formula:

[0049]

[0050] Among them, α,α ′ ,α1,α ′ 1,α2,α ′ 2∈{1,2,…,N π},β,β ′ ,β1,β ′ 1,β2,β ′ 2∈{1,2,…,N ν}, a is the production and annihilation operator, respectively. The subscripts π and v indicate the proton and neutron corresponding terms, respectively. The following calculation coefficients are:

[0051]

[0052]

[0053] in, is the momentum of the nucleus.

[0054] In one embodiment, the mean field potential term To describe the spin-orbit coupling effect, the angular momentum eigenstate can be used as a single-particle state, which can be expressed as:

[0055]

[0056] Among them, ψ nlm Right now is the three-dimensional harmonic oscillator wave function, is the Clebsch-Gordan coefficient. Where n is the principal quantum number, l is the orbital quantum number, j is the total angular momentum, and m is the j is the projection of the total angular momentum on the axis (-j≤m j ≤j), m s is the projection of the spin angular momentum on the axis. In one embodiment, R nl The specific expression of (r) can be:

[0057]

[0058] in, is the associated Laguerre polynomial, α=1.1 / A 1 / 6 fm -1 , A is the total number of nucleons, is the normalization constant.

[0059] In one embodiment, since protons and neutrons are spin 1 / 2 fermions, each single-particle state can be occupied by at most one particle, so a quantum bit (qubit) can represent the number of occupants of a single-particle state. Taking a single-particle state as an example, |0> can represent that there is no particle in the single-particle state, and |1> can represent that there is one particle in the single-particle state. The state of the nucleus can be represented by the linear normalized superposition of quantum states, so the above nucleus requires a total of N π +N ν There are only Z working bits in the proton part that are in the state of |1>, and only N bits in the neutron part that are in the state of |1>.

[0060] Since the generation and annihilation operators in formula (3) a cannot act directly on the quantum state in the form of qubits, that is, it cannot be implemented through a quantum circuit. Therefore, through the Jordan-Wigner transformation, the creation and annihilation operators a can be expressed as a linear combination of the direct products of Pauli operators. Moreover, since the second quantization Hamiltonian of the atomic nucleus has been expressed as a combination of creation and annihilation operators, the Hamiltonian of the atomic nucleus can ultimately also be expressed as a linear combination of the direct products of Pauli operators. In a specific embodiment, the final Hamiltonian (Hamiltonian operator) is expressed as where α k is the superposition coefficient, is the Pauli operator, M is the number of Pauli operators, and k is the serial number of the Pauli operator.

[0061] Therefore, in one embodiment, the first quantum state can be obtained based on second quantization and the Jordan-Wigner transformation.

[0062] Step 22, set the first quantum circuit according to the Hamiltonian operator.

[0063] In this step, according to the final Hamiltonian operator obtained in Step 21, a quantum circuit is set such that the quantum state descends along the gradient with respect to the ground state. Furthermore, through the iterative execution of this quantum circuit, a quantum state that gradually approaches the ground state of the atomic nucleus can be continuously obtained. The process of setting the quantum circuit is introduced in detail below.

[0064] Essentially, the simulation of the atomic nucleus aims to obtain the ground state and ground state energy of the atomic nucleus. The smallest eigenvalue among the eigenvalues of the Hamiltonian H in the corresponding reduced Hilbert space is the ground state energy of the atomic nucleus. Therefore, according to one implementation, it can be first assumed that the number of eigenvalues of the reduced Hamiltonian of the atomic nucleus is where C is the permutation operator, and it is assumed that its eigenstates and eigenvalues are: Its eigenvalues have a magnitude order of λ0 ≤ λ1 ≤ … ≤ λ d-1 , and the upper bounds of λ0 and λ d-1 can be estimated according to experience, such that λ0 < q, λ d-1 < Q. Note that according to the above assumptions, only the number of eigenstates and eigenvalues, as well as the upper bounds, are obtained, and the specific eigenstates and eigenvalues are not obtained. Among them, the eigenstate (ground state) with the smallest eigenvalue (ground state energy) needs to be obtained through the set quantum circuit.

[0065] As described above, since the execution of the quantum circuit usually goes through multiple iterations, the step size of each iteration can be preset. In one embodiment, the set iteration step size γ satisfies the following constraints:

[0066]

[0067] In one embodiment, the initial state of the quantum circuit input can be And c0≠0. Where |u> is the eigenstate of the nuclear reduced Hamiltonian, ku is the serial number of the eigenstate, and c is the coefficient of the eigenstate. Therefore, the nuclear energy is <e>=<φ (0) |H|φ (0) >, based on the nuclear energy, the energy gradient of the quantum state can be calculated as: Furthermore, the iteration operator corresponding to the quantum circuit can be determined: And use the iterative formula |φ (s+1) >=T|φ (s) >, to approximate the ground state of the nucleus. Where s is the number of the iterative input quantum state, and s+1 is the number of the iterative output quantum state. Specifically, according to the above iterative operator and iterative formula, we have The result after t iterations is in, is a normalization constant, which means that after multiple iterations, we can gradually approach the ground state of the nucleus |u0>.

[0068] However, since quantum computers can only directly and efficiently implement unitary operators, and T is generally not a unitary operator, it cannot be directly implemented using quantum computers. It has been written as a linear combination of the direct product form of Pauli operators, which is a unitary operator, so T has been decomposed into the form of a linear combination of unitary operators. In this case, it can be realized by introducing auxiliary bits (auxiliary systems) outside the working bits (working systems) of the quantum circuit and using the dual quantum computing model.

[0069] Specifically, in one embodiment, an auxiliary system and a working system may be provided, wherein the working system and the auxiliary system respectively include a number of bits; a number of computational basic eigenstates of the auxiliary system are determined; and according to the Hamidar quantity and a preset iteration step, a number of first weights respectively corresponding to the number of computational basic eigenstates and a number of unitary quantum gates respectively corresponding to the number of computational basic eigenstates are determined.

[0070] It should be noted that in this specification, the decomposition formulas of the Hamiltonian operator and the iterative operator are and The number of Pauli basic operators in the Hamiltonian is represented by M. In a specific embodiment, they may be equal or differ by 1. Generally speaking, if the Hamiltonian decomposition includes the identity operator I, the two are equal. Otherwise, the number of basic operators in the Hamiltonian decomposition is 1 less than the iterative operator. However, the identity operator I can always be added to the Hamiltonian decomposition, and it is agreed that the superposition coefficient can be 0. Therefore, the number of basic operators contained in the two can be represented by M.

[0071] Step 23, obtaining a first quantum state of the atomic nucleus, and running a first quantum circuit according to the first quantum state to obtain a second quantum state, wherein the second quantum state is closer to the ground state of the atomic nucleus than the first quantum state.

[0072] In this step, the quantum circuit set in step 22 can be run according to the initial state (first quantum state) of the obtained atomic nucleus to obtain a subsequent quantum state that is closer to the ground state of the atomic nucleus relative to the first quantum state. Then, the quantum circuit can be iteratively run in the above manner according to the subsequent quantum state. In one embodiment, after a preset number of iterative runs, the final quantum state obtained can be used as the ground state. And the ground state energy of the atomic nucleus is obtained according to the expected value of the Hamiltonian on the final quantum state. In another embodiment, it can also be determined whether the iteration can be terminated according to whether the difference between the quantum states obtained in two adjacent iterations is less than a predetermined threshold. If the difference is less than the predetermined threshold, the quantum state obtained in the latter iteration of the two adjacent iterations can be used as the ground state, and the ground state energy of the atomic nucleus can be obtained according to the expected value of the Hamiltonian on the quantum state.

[0073] In different embodiments, different initial states of the nucleus can be obtained. In one embodiment, the first quantum state obtained |φ (0) > can be a Hartree-Fock state, which has the advantage of satisfying the above c0≠0 and being relatively close to the true ground state, thereby reducing the number of iterations and greatly improving efficiency. Therefore, in the Hartree-Fock state, protons and neutrons are arranged as much as possible from the low-energy single-particle state to the high-energy single-particle state, that is, the Hartree-Fock state itself is a rough approximation of the ground state of the nucleus.

[0074] Specifically, in one embodiment, the auxiliary system can be prepared as a superposition state of the several computing basic eigenstates, in which the weights of the various computing basic eigenstates are the corresponding first weights; the working system is prepared as the first quantum state; according to the state of the auxiliary system, the several unitary quantum gate operations are applied to the working system; a Hardmard gate is applied to each quantum bit in the auxiliary system; the state of the auxiliary system is measured, and when it is in the |0〉 state, the quantum final state of the working system is read to obtain a second quantum state.

[0075] like Figure 1 As shown, after iteratively running the quantum circuit, the final output result is obtained, and the ground state under the nuclear coordinate representation is obtained. The ground state energy of the nucleus can also be obtained by measuring the expectation value of the Hamiltonian at the final quantum state.

[0076] The method is further described below through a specific embodiment. Figure 3 Schematic diagram of a first quantum circuit provided by an embodiment of the present invention. Figure 3 As shown, it is possible to introduce Auxiliary bits, initialize the quantum state on the auxiliary bits to: in, is the normalization constant, and k is the basic characteristic state of the auxiliary system. Then, the total initial state of the working system and the auxiliary system can be expressed as |ψ k >|φ (0) >.

[0077] In order to apply the iteration operator T to |φ (0) >, we can first put the controlled operator Act on |ψ k >|φ (0) >, we get: Then a Hardmard gate is applied to each auxiliary bit: The part of the final quantum state where the auxiliary bit is |0> is: Therefore, if the auxiliary bit is measured to obtain |0>, the quantum state of the working bit is exactly |φ (1) >=T|φ (0) >.

[0078] In a subsequent iteration, you can use |φ (1) >As the new initial state on the working bit, the quantum state on the auxiliary bit is re-prepared as |ψ s >, repeat the above operation to get |φ (2) >, similarly we can get |φ (3) >、|φ (4) >、…、|φ (t) >(t is the preset number of iterations). Finally, use |φ (t) > as an estimate of the ground state of the nucleus, and the ground state energy of the nucleus is: E0=<φ (t) |H|φ (t) >.

[0079] According to another embodiment, a device for simulating atomic nuclei based on quantum computing is provided. Figure 4 The structure diagram of a nuclear simulation device based on quantum computing provided by an embodiment of the present invention. Figure 4 As shown, the device 400 includes:

[0080] The Hamiltonian acquisition unit 41 is configured to determine the Hamiltonian operator corresponding to the atomic nucleus in the atomic nucleus shell model;

[0081] A quantum circuit setting unit 42 is configured to set a first quantum circuit according to the Hamiltonian operator;

[0082] The quantum circuit execution unit 43 is configured to obtain a first quantum state of the atomic nucleus, and according to the first quantum state, run the first quantum circuit to obtain a second quantum state, wherein the second quantum state is closer to the ground state of the atomic nucleus than the first quantum state.

[0083] According to another embodiment of the present invention, there is also provided a computer readable medium, comprising a computer program stored thereon, wherein the computer executes Figure 1 The method described.

[0084] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0085] The professionals should further realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to the function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0086] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0087] 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.< / e>

Claims

1. A method for simulating atomic nuclei based on quantum computing, the method comprising: Determine the Hamiltonian operator corresponding to the nucleus in the nuclear shell model; According to the Hamiltonian operator, setting a first quantum circuit; The step of setting a first quantum circuit according to the Hamiltonian operator includes: setting an auxiliary system and a working system, wherein the working system and the auxiliary system each include a plurality of bits; determining a plurality of basic computational eigenstates of the auxiliary system; and determining a plurality of first weights respectively corresponding to the plurality of basic computational eigenstates and a plurality of unitary quantum gates respectively corresponding to the plurality of basic computational eigenstates according to the Hamiltonian operator and a preset iteration step size. A first quantum state of an atomic nucleus is obtained, and a first quantum circuit is operated according to the first quantum state to obtain a second quantum state, wherein the second quantum state is closer to a ground state of the atomic nucleus than the first quantum state, wherein the first quantum state is obtained based on secondary quantization and Jordan-Wigner transformation.

2. The method according to claim 1, further comprising: The expectation value of the Hamiltonian in the second quantum state is measured to obtain the ground state energy of the nucleus.

3. The method according to claim 1, wherein: The first quantum state is a Hartree-Fock state.

4. The method according to claim 1, wherein: The step of operating the first quantum circuit to obtain the second quantum state includes: The auxiliary system is prepared as a superposition state of the plurality of basic computing eigenstates, wherein the weights of the various basic computing eigenstates are the corresponding first weights; preparing the working system to be in the first quantum state; applying the plurality of unitary quantum gate operations to the working system according to the state of the auxiliary system; Apply a Hardmard gate to each qubit in the auxiliary system; The state of the auxiliary system is measured. When it is in the |0〉 state, the final quantum state of the working system is read to obtain the second quantum state.

5. The method according to claim 1, wherein: The unitary quantum gate is a Pauli gate.

6. A nuclear simulation device based on quantum computing, the device comprising: A Hamiltonian acquisition unit is configured to determine a Hamiltonian operator corresponding to an atomic nucleus in an atomic nucleus shell model; A quantum circuit setting unit is configured to set a first quantum circuit according to the Hamiltonian operator; The step of setting a first quantum circuit according to the Hamiltonian operator includes: setting an auxiliary system and a working system, wherein the working system and the auxiliary system each include a plurality of bits; determining a plurality of basic computational eigenstates of the auxiliary system; and determining a plurality of first weights respectively corresponding to the plurality of basic computational eigenstates and a plurality of unitary quantum gates respectively corresponding to the plurality of basic computational eigenstates according to the Hamiltonian operator and a preset iteration step size. The quantum circuit execution unit is configured to obtain a first quantum state of the atomic nucleus, and according to the first quantum state, run a first quantum circuit to obtain a second quantum state, wherein the second quantum state is closer to the ground state of the atomic nucleus than the first quantum state, and wherein the first quantum state is obtained based on secondary quantization and Jordan-Wigner transformation.

7. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to execute the method according to any one of claims 1 to 5.

8. A computing device, comprising a memory and a processor, wherein the memory stores executable code, and when the processor executes the executable code, the method according to any one of claims 1 to 5 is implemented.

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