Generating Approximate Ground States of Strongly Correlated Quantum Many-Body Systems Through Quantum Imaginary Time Evolution

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Kaicher, Michael P., Dommert, Florian, Wever, Christopher, Amsler, Maximilian, Kühn, Michael
Formato: Preprint
Publicado: 2024
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866914934045016064
author Kaicher, Michael P.
Dommert, Florian
Wever, Christopher
Amsler, Maximilian
Kühn, Michael
author_facet Kaicher, Michael P.
Dommert, Florian
Wever, Christopher
Amsler, Maximilian
Kühn, Michael
contents Most quantum algorithms designed to generate or probe properties of the ground state of a quantum many-body system require as input an initial state with a large overlap with the desired ground state. One approach for preparing such a ground state is Imaginary Time Evolution (ITE). Recent work by [Motta, M., Sun, C., Tan, A.T.K. et al. (2020)] introduced an algorithm -- which we will refer to as Quantum Imaginary Time Evolution (QITE) -- that shows how ITE can be approximated by a sequence of unitary operators, making QITE potentially implementable on early fault-tolerant quantum computers. In this work, we provide a heuristic study of the capabilities of the QITE algorithm in approximating the ITE of lattice and molecular electronic structure Hamiltonians. We numerically study the performance of the QITE algorithm when provided with a good classical initial state for a large class of systems, some of which are of interest to industrial applications, and check if QITE is able to qualitatively replicate the ITE behavior and improve over a classical mean-field solution. The systems we consider in this work range from one- and two-dimensional lattice systems of various lattice geometries displaying short- and long-range interactions, to active spaces of molecular electronic structure Hamiltonians. In addition to the comparison of QITE and ITE, we explicitly show how imaginary time evolved fermionic Gaussian states can serve as initial states which can be efficiently computed on classical computers and efficiently implemented on quantum computers for generic spin Hamiltonians in arbitrary lattice geometries and dimensions, which can be of independent interest.
format Preprint
id arxiv_https___arxiv_org_abs_2409_01320
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Generating Approximate Ground States of Strongly Correlated Quantum Many-Body Systems Through Quantum Imaginary Time Evolution
Kaicher, Michael P.
Dommert, Florian
Wever, Christopher
Amsler, Maximilian
Kühn, Michael
Quantum Physics
Materials Science
Strongly Correlated Electrons
Superconductivity
Most quantum algorithms designed to generate or probe properties of the ground state of a quantum many-body system require as input an initial state with a large overlap with the desired ground state. One approach for preparing such a ground state is Imaginary Time Evolution (ITE). Recent work by [Motta, M., Sun, C., Tan, A.T.K. et al. (2020)] introduced an algorithm -- which we will refer to as Quantum Imaginary Time Evolution (QITE) -- that shows how ITE can be approximated by a sequence of unitary operators, making QITE potentially implementable on early fault-tolerant quantum computers. In this work, we provide a heuristic study of the capabilities of the QITE algorithm in approximating the ITE of lattice and molecular electronic structure Hamiltonians. We numerically study the performance of the QITE algorithm when provided with a good classical initial state for a large class of systems, some of which are of interest to industrial applications, and check if QITE is able to qualitatively replicate the ITE behavior and improve over a classical mean-field solution. The systems we consider in this work range from one- and two-dimensional lattice systems of various lattice geometries displaying short- and long-range interactions, to active spaces of molecular electronic structure Hamiltonians. In addition to the comparison of QITE and ITE, we explicitly show how imaginary time evolved fermionic Gaussian states can serve as initial states which can be efficiently computed on classical computers and efficiently implemented on quantum computers for generic spin Hamiltonians in arbitrary lattice geometries and dimensions, which can be of independent interest.
title Generating Approximate Ground States of Strongly Correlated Quantum Many-Body Systems Through Quantum Imaginary Time Evolution
topic Quantum Physics
Materials Science
Strongly Correlated Electrons
Superconductivity
url https://arxiv.org/abs/2409.01320