CN-115244549-B - Method and apparatus for resource optimized fermi partial simulation on quantum computers for quantum chemistry

Abstract

Aspects of the present disclosure describe a method comprising predicting a first set ansatz of items and a plurality of first magnitudes associated with the first set ansatz of items, minimizing energy of a system based on the first set ansatz of items and the plurality of first magnitudes, calculating a disturbance correction using one or more ansatz wave functions, determining whether energy of the system is converging, and predicting a second set ansatz of items and a plurality of second magnitudes associated with the second set ansatz of items in response to determining that energy of the system is not converging.

Inventors

• WANG QINGFENG
• LI MING
• Nan Yunsheng

Assignees

• 爱奥尼克公司
• 马里兰大学帕克分校

Dates

Publication Date

20260512

Application Date

20210218

Priority Date

20210217

Claims (18)

1. 1. A method of performing a simulation of a chemical system, comprising: Predicting, by a classical processor, a first set ansatz of items and a first initial amplitude associated with the first set ansatz of items; Minimizing, by the classical processor, energy of the chemical system based on the first set ansatz of items and the first initial amplitude; iteratively applying, by the classical processor, one or more disturbance corrections until the energy converges, comprising: calculating at least one disturbance correction in the energy or wave function based on one or more ansatz wave functions; Determining whether the energy of the chemical system converges based on the calculated at least one disturbance correction; Predicting a second set ansatz of items and a second initial amplitude associated with the second set ansatz of items when the energy of the chemical system does not converge based on the determination; Determining whether the energy of the chemical system converges based on an additional disturbance correction selected based on the second set ansatz of terms and the magnitude of the second initial amplitude; generating, by the classical processor, a ground state energy estimate of particles of the chemical system when the energy of the chemical system converges based on the one additional disturbance correction; Compiling, by the classical processor, a circuit from a simulation of the chemical system based on the ground state energy estimate of the particle, wherein the compiling comprises mapping ansatz items that lead to convergence of the chemical system to a qubit index by: Converting the fermi sub-operators contained in the ansatz items into qubit operations using one or more fermi sub-to-qubit transformations; Assigning a qubit operation executable by a quantum processor to the qubit index, wherein the qubit index indicates placement and application of gates within the circuit, and The circuitry is executed by the quantum processor to determine at least one of a chemical reaction, a bonding characteristic, and an energy state of the chemical system.
2. 2. The method of claim 1, further comprising minimizing energy of the chemical system based on the second set ansatz of items.
3. 3. A method according to claim 1, wherein predicting the first set ansatz of terms and the first initial amplitude comprises predicting using second order M player-Plesset (MP 2) perturbation theory.
4. 4. The method of claim 1, wherein the first set ansatz of items comprises a unitary coupling cluster ansatz with single or dual excitation.
5. 5. The method of claim 1, wherein minimizing the energy of the chemical system comprises calculating the energy using a variable component sub-eigensolver (VQE) method.
6. 6. The method of claim 5, further comprising calculating an energy corrector by a hybrid second order M-llar-Plesset perturbation (HMP 2) method.
7. 7. The method of claim 1, further comprising executing the circuit by a quantum computer.
8. 8. The method of claim 1, wherein predicting the second set ansatz of items and the second initial amplitude comprises increasing a ansatz size of the second set ansatz of items.
9. 9. The method of claim 1, wherein predicting the second set ansatz of terms and the second initial amplitude comprises: determining one or more additional ansatz items to add to the first set ansatz of items for generating the second set ansatz of items, and Adding the one or more additional ansatz items to the first set ansatz of items to generate the second set ansatz of items, and Minimizing energy of the chemical system based on the second set ansatz of items and the second initial amplitude.
10. 10. A non-transitory computer readable medium for performing a simulation of a chemical system, the non-transitory computer readable medium storing instructions that, when executed by a classical processor, cause the classical processor to: predicting a first set ansatz of items and a first initial amplitude associated with the first set ansatz of items; Minimizing energy of the chemical system based on the first set ansatz of items and the first initial amplitude; Iteratively applying one or more disturbance corrections until the energy converges, comprising: calculating at least one disturbance correction in the energy or wave function based on one or more ansatz wave functions; Determining whether the energy of the chemical system converges based on the calculated at least one disturbance correction; Predicting a second set ansatz of items and a second initial amplitude associated with the second set ansatz of items when the energy of the chemical system does not converge based on the determination, and Determining whether the energy of the chemical system converges based on an additional disturbance correction selected based on the second set ansatz of terms and the magnitude of the second initial amplitude; generating a ground state energy estimate of particles of the chemical system when the energy of the chemical system converges based on the one additional disturbance correction; Compiling a circuit from a simulation of the chemical system based on a ground state energy estimate of the particle, wherein the compiling comprises mapping ansatz terms that result in convergence of the chemical system to a qubit index by: Converting the fermi sub-operators contained in the ansatz items into qubit operations using one or more fermi sub-to-qubit transformations; a qubit operation executable by a quantum processor is assigned to the qubit index, wherein the qubit index indicates placement and application of gates within the circuit, and wherein the circuit is executed by the quantum processor to determine at least one of a chemical reaction, a bonding characteristic, and an energy state of the chemical system.
11. 11. The non-transitory computer-readable medium of claim 10, further comprising instructions for minimizing energy of the chemical system based on the second set ansatz of items.
12. 12. A non-transitory computer readable medium according to claim 10, wherein the instructions for predicting the first set ansatz of terms and the first initial amplitude include instructions for predicting using second order brave-pleset (MP 2) perturbation theory.
13. 13. The non-transitory computer-readable medium of claim 10, wherein the first set ansatz comprises a unitary coupling cluster ansatz with single or dual excitation.
14. 14. The non-transitory computer-readable medium of claim 10, wherein the instructions for minimizing energy of the chemical system comprise instructions for calculating energy using a variable component sub-eigensolver (VQE) method.
15. 15. The non-transitory computer-readable medium of claim 14, further comprising instructions for calculating an energy corrector by a hybrid second order M-brag llar-pleset perturbation (HMP 2) method.
16. 16. The non-transitory computer readable medium of claim 10, further comprising Instructions of the circuit are executed by a quantum computer.
17. 17. The non-transitory computer-readable medium of claim 10, wherein the instructions for predicting the second set ansatz of items and the second initial amplitude comprise instructions for increasing a ansatz size of the second set ansatz of items.
18. 18. The non-transitory computer-readable medium of claim 10, wherein the instructions for predicting the second set ansatz of terms and the second initial amplitude comprise instructions for: determining one or more additional ansatz items to add to the first set ansatz of items for generating the second set ansatz of items, and Adding the one or more additional ansatz items to the first set ansatz of items to generate the second set ansatz of items, and Minimizing energy of the chemical system based on the second set ansatz of items and the second initial amplitude.

Description

Method and apparatus for resource optimized fermi partial simulation on quantum computers for quantum chemistry Cross Reference to Related Applications The present application claims priority and equity from U.S. non-provisional application Ser. No. 17/177,813, entitled "METHODS AND APPARATUSES FOR RESOURCE-OPTIMIZED FERMIONIC LOCAL SIMULATION ON QUANTUM COMPUTER FOR QUANTUM CHEMISTRY", filed on month 2, 17 of 2021, U.S. provisional application Ser. No. 62/979,974, entitled "METHODS AND APPARATUSES FOR RESOURCE-OPTIMIZED FERMIONIC LOCAL SIMULATION ON QUANTUM COMPUTER FOR QUANTUM CHEMISTRY", filed on month 21 of 2020, and U.S. provisional application Ser. No. 63/130,088, entitled "METHODS AND APPARATUSES FOR RESOURCE-OPTIMIZED FERMIONIC LOCAL SIMULATION ON QUANTUM COMPUTER FOR QUANTUM CHEMISTRY", filed on month 12, 23 of 2020, the contents of which are incorporated herein by reference in their entirety. Government licensing rights The invention is completed under the government support of DOE basic energy science foundation DOE BES award de-sc 0019449. The government has certain rights in this invention. Technical Field Aspects of the present disclosure generally relate to improving resource utilization in quantum computers. Background Atomic fluxes can be generated and used as a neutral atom or ion source for certain systems. For example, some of these systems may include Quantum Information Processing (QIP) systems. Trapping ions is one of the main embodiments of QIP systems. The atomic-based qubits can be used as quantum gates in quantum memories, quantum computers, and simulators, and can be used as nodes of quantum communication networks. Qubits based on trapping atomic ions enjoy a rare combination of properties. For example, quantum bits based on trapped atomic ions have very good coherence properties, can be prepared and measured with near 100% efficiency, and are easily entangled with each other using a suitable external control field (e.g., optical or microwave field). These properties make atomic-based qubits attractive for extended quantum operations (e.g., quantum computing or quantum simulation). One application of quantum simulation is the use of QIP systems to simulate fermi-seed substances, including fermi-seeds that undergo local interactions. Fermi subsystem simulation on quantum computers can include two methods, a variable component classical mixing strategy for imperfect, pre-fault tolerant (pre-FT) quantum computers and a hamiltonian dynamics simulation based on quantum simulation algorithms for Fault Tolerant (FT) quantum computers. In the context of the ground state energy estimation of the fermi subsystem, the former utilizes efficient preparation of the well-favored ansatz state of ground state and a method of evaluating the hamiltonian expectation of the prepared ansatz state system, both enabled by quantum computers. In contrast, the latter effectively mimics a quantum system with localized hamiltonian using the capabilities of a quantum computer, which in combination with quantum phase estimation, can evaluate the ground state energy of the system. In the pre-FT scheme, the quantum computation cost may be dominated by the multiple quantum bit gate. In contrast, in FT schemes, the circuit is typically written on the clifford+t gate set, and the quantum computation cost may be determined byMany of which are used forIn the FT embodiment of the gate. Thus, improvements in analog quantum systems may be desirable. Disclosure of Invention The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later. One aspect of the disclosure includes a method that includes predicting a first set ansatz of items and a plurality of first magnitudes associated with the first set ansatz of items, minimizing energy of a system based on the first set ansatz of items and the plurality of first magnitudes, calculating a disturbance correction using one or more ansatz wave functions, determining whether energy of the system converges, and predicting a second set ansatz of items and a plurality of second magnitudes associated with the second set ansatz of items in response to determining that energy of the system does not converge. In another aspect of the disclosure, a quantum computing device is included that is configured to perform the steps of predicting a first set ansatz of terms and a plurality of first magnitudes associated with the first set ansatz of terms, minimizing energy of a system based on the first set ansatz of terms and the plurality of first magnitudes, calculating a disturbance