EP-4742110-A1 - INFORMATION PROCESSING PROGRAM, INFORMATION PROCESSING METHOD, AND INFORMATION PROCESSING DEVICE

EP4742110A1EP 4742110 A1EP4742110 A1EP 4742110A1EP-4742110-A1

Abstract

An information processing program for causing a computer to execute a process including: generating a plurality of first quantum circuits by a local compilation method, the first quantum circuits representing an action of a time evolution operator for a first time period and having a depth smaller than a depth of a first target quantum circuit representing the action of the time evolution operator for the first time period; and generating a second quantum circuit by the local compilation method, the second quantum circuit being smaller in depth than a second target quantum circuit obtained by combining two or more of the generated first quantum circuits and representing the action of the time evolution operator for a second time period longer than the first time period, the second quantum circuit representing the action of the time evolution operator for the second time period.

Inventors

Kanasugi, Shota

Assignees

FUJITSU LIMITED

Dates

Publication Date: 20260513
Application Date: 20251104

Claims (14)

An information processing program for causing a computer to execute a process, the process comprising: generating a plurality of first quantum circuits by a local compilation method, the first quantum circuits representing an action of a time evolution operator for a first time period and having a depth smaller than a depth of a first target quantum circuit representing the action of the time evolution operator for the first time period; and generating a second quantum circuit by the local compilation method, the second quantum circuit being smaller in depth than a second target quantum circuit obtained by combining two or more of the generated first quantum circuits and representing the action of the time evolution operator for a second time period longer than the first time period, the second quantum circuit representing the action of the time evolution operator for the second time period.
The information processing program according to claim 1, wherein the second time period is two times longer than the first time period.
The information processing program according to claim 1 or claim 2, the process further comprising: obtaining a third target quantum circuit by combining the first quantum circuit and the second quantum circuit generated immediately before, the third target quantum circuit representing the action of the time evolution operator for a third time period longer than the second quantum circuit by the first time period; and newly generating, by the local compilation method, the second quantum circuit smaller in depth than the third target quantum circuit and representing the action of the time evolution operator for the third time period, wherein the obtaining the third target quantum circuit and the newly generating the second quantum circuit are repeatedly executed until a condition is satisfied.
The information processing program according to claim 1 or claim 2, further comprising: obtaining a third target quantum circuit by combining two of the second quantum circuits that are generated immediately before and represent the action of the time evolution operator for a third time period that is twice as long as the second quantum circuit; and newly generating, by the local compilation method, the second quantum circuit that is smaller in depth than the third target quantum circuit and represents the action of the time evolution operator for the third time period, wherein the obtaining the third target quantum circuit and the newly generating the second quantum circuit are repeatedly executed until a predetermined condition is satisfied.
The information processing program according to any one of claims 1 to 4, the process further comprising newly generating the second quantum circuit by the local compilation method, the newly generated second quantum circuit being smaller in depth than a third target quantum circuit, the newly generated second quantum circuit being obtained by selectively combining a plurality of quantum circuits from a quantum circuit set including the first quantum circuits and the generated second quantum circuit, the third target quantum circuit representing the action of the time evolution operator for a third time period longer than the second quantum circuit generated immediately before, wherein the newly generating the second quantum circuit is repeatedly executed until a condition is satisfied.
The information processing program according to any one of claims 1 to 5, wherein the generating the first quantum circuit includes obtaining, by a Trotter decomposition method, the first target quantum circuits representing the action of the time evolution operator for the first time period.
The information processing program according to claim 3, the condition is that the newly generated second quantum circuit is generated according to a local compilation theorem, represents the action of the time evolution operator for a maximum one of a plurality of multiples of the first time period, and is included in a time domain representing the action of the time evolution operator.
The information processing program according to claim 4, wherein the predetermined condition is that the newly generated second quantum circuit is generated according to a local compilation theorem, represents the action of the time evolution operator for a maximum one of a plurality of multiples of a power of 2 of the first time period, and is included in a time domain representing the action of the time evolution operator.
The information processing program according to any one of claims 1 to 8, wherein the generating the first quantum circuits includes expanding each to a size corresponding to the second time period that is two times the first period, and the generating the second quantum circuit includes obtaining the second target quantum circuit by combining two of the expanded first quantum circuits and generating the second quantum circuit by the local compilation method, the second quantum circuit being smaller in depth than the second target quantum circuit and representing the action of the time evolution operator for the second time period.
The information processing program according to claim 3, wherein the generating the first quantum circuits includes expanding each to a size corresponding to a third time period longer than the second time period by the first period, and the newly generating the second quantum circuit includes expanding the second quantum circuit generated immediately before to the size corresponding to the third time period, combining one of the expanded first quantum circuits and the expanded second quantum circuit to obtain a third target quantum circuit representing the action of the time evolution operator for the third time period, and newly generating the second quantum circuit by the local compilation method, the newly generated second quantum circuit being smaller in depth than the third target quantum circuit and representing the action of the time evolution operator for the third time period.
The information processing program according claim 4, wherein the newly generating the second quantum circuit includes expanding the second quantum circuit generated immediately before to a size corresponding to a third time period two times longer than the second time period, combining two expanded second quantum circuits to obtain a third target quantum circuit representing the action of the time evolution operator for the third time period, and newly generating the second quantum circuit by the local compilation method, the newly generated second quantum circuit being smaller in depth than the third target quantum circuit and representing the action of the time evolution operator for the third time period.
The information processing program according to any one of claims 1 to 11, the process further comprising selectively combining a plurality of quantum circuits from a set including the first quantum circuits and each generated second quantum circuit and thereby obtaining a quantum circuit representing the action of the time evolution operator for a time period, and simulating a temporal change of a quantum state for the time period, based on the obtained quantum circuit.
An information processing method executed by a computer, the method comprising: generating a plurality of first quantum circuits by a local compilation method, the first quantum circuits representing an action of a time evolution operator for a first time period and having a depth smaller than a depth of a first target quantum circuit representing the action of the time evolution operator for the first time period; and generating a second quantum circuit by the local compilation method, the second quantum circuit being smaller in depth than a second target quantum circuit obtained by combining two or more of the generated first quantum circuits and representing the action of the time evolution operator for a second time period longer than the first time period, the second quantum circuit representing the action of the time evolution operator for the second time period.
An information processing device, comprising: a memory; a processor coupled to the memory, the processor configured to: generate a plurality of first quantum circuits by a local compilation method, the first quantum circuits representing an action of a time evolution operator for a first time period and having a depth smaller than a depth of a first target quantum circuit representing the action of the time evolution operator for the first time period; and generate a second quantum circuit by the local compilation method, the second quantum circuit being smaller in depth than a second target quantum circuit obtained by combining two or more of the generated first quantum circuits and representing the action of the time evolution operator for a second time period longer than the first time period, the second quantum circuit representing the action of the time evolution operator for the second time period.

Description

FIELD The embodiments discussed herein are related to an information processing program, an information processing method, and an information processing device. BACKGROUND Conventionally, when a quantum many-body system simulation is performed in the field of material development, drug discovery research, or the like, a quantum circuit expressing the action of a time evolution operator is generated. Here, in order to maintain the accuracy of the quantum chemical calculation in the quantum many-body system simulation, it is desirable to reduce the number of operations in the quantum circuit. For example, when the number of operations in the quantum circuit is large due to the large number of quantum gates, errors occurring in the qubit due to environmental noise, interference of other qubits, noise during operation of the qubit, and the like may be cumulative for each quantum gate. One prior art includes, for example, locally rendering non-local quantum dynamics. Further, for example, there is a technique for realizing an effect of imaginary time evolution by real time unitary evolution related to a Hamiltonian of a system. In addition, for example, there is a technique of implementing a real-time evolution unitary of a Hamiltonian. In addition, for example, there is a technique of encoding a calculation problem into a problem Hamiltonian. For example, refer to Published Japanese-Translation of PCT Application, Publication No. 2022-538721, Published Japanese-Translation of PCT Application, Publication No. 2023-535109, U.S. Patent Application Publication No. 2020/0143280, and U.S. Patent Application Publication No. 2022/0207402. SUMMARY It is an object in one aspect of the embodiments to at least solve the above problems in the conventional technologies. According to an aspect of an embodiment, an information processing program for causing a computer to execute a process including: generating a plurality of first quantum circuits by a local compilation method, the first quantum circuits representing an action of a time evolution operator for a first time period and having a depth smaller than a depth of a first target quantum circuit representing the action of the time evolution operator for the first time period; and generating a second quantum circuit by the local compilation method, the second quantum circuit being smaller in depth than a second target quantum circuit obtained by combining two or more of the generated first quantum circuits and representing the action of the time evolution operator for a second time period longer than the first time period, the second quantum circuit representing the action of the time evolution operator for the second time period. BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is an explanatory diagram depicting an example of an information processing method according to an embodiment.Fig. 2 is an explanatory diagram depicting an example of an information processing system 200.Fig. 3 is a block diagram of an example of a hardware configuration of an information processing device 100.Fig. 4 is a block diagram depicting an example of a hardware configuration of a computing device 201.Fig. 5 is a block diagram depicting an example of a functional configuration of the information processing device 100.Fig. 6 is an explanatory diagram depicting an example in which an ETS method is used.Fig. 7 is an explanatory diagram depicting an example in which the ETS method is used.Fig. 8 is an explanatory diagram depicting an example in which the ETS method is used.Fig. 9 is an explanatory diagram depicting an example of setting a compile size L~_j.Fig. 10 is an explanatory diagram depicting an example of performing a quantum many-body system simulation for a long time.Fig. 11 is an explanatory diagram depicting an example in which a BTS method is used.Fig. 12 is an explanatory diagram depicting an example in which the BTS method is used.Fig. 13 is an explanatory diagram depicting an example in which the BTS method is used.Fig. 14 is an explanatory diagram depicting an example of effects in a case of using the ETS method and a case of using the BTS method.Fig. 15 is an explanatory diagram depicting an example of effects in a case of using the ETS method and a case of using the BTS method.Fig. 16 is an explanatory diagram depicting a first embodiment of the information processing device 100.Fig. 17 is an explanatory diagram depicting an example of verification of accuracy when the ETS method in the first embodiment is used.Fig. 18 is an explanatory diagram depicting an example of verification of accuracy when the ETS method in the first embodiment is used.Fig. 19 is an explanatory diagram depicting an example of verification of accuracy when the BTS method is used in the first embodiment.Fig. 20 is an explanatory diagram depicting an example of verification of accuracy when the BTS method is used in the first embodiment.Fig. 21 is an explanatory diagram depicting an example in which a depth of a va