Efficient ground state preparation in variational quantum eigensolver with symmetry-breaking layers

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autor principal: Park, Chae-Yeun
Formato: Preprint
Publicado: 2021
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866910310484410368
author Park, Chae-Yeun
author_facet Park, Chae-Yeun
contents Variational quantum eigensolver (VQE) solves the ground state problem of a given Hamiltonian by finding the parameters of a quantum circuit ansatz that minimizes the Hamiltonian expectation value. Among possible quantum circuit ansätze, the Hamiltonian variational ansatz (HVA) is widely studied for quantum many-body problems as the ansatz with sufficiently large depth is theoretically guaranteed to express the ground state. However, since the HVA shares the same symmetry with the Hamiltonian, it is not necessarily good at finding the symmetry-broken ground states that prevail in nature. In this paper, we systematically explore the limitations of the HVA for solving symmetry-broken systems and propose an alternative quantum circuit ansatz with symmetry-breaking layers. With extensive numerical simulations, we show that the proposed ansatz finds the ground state in depth significantly shorter than the bare HVA when the target Hamiltonian has symmetry-broken ground states.
format Preprint
id arxiv_https___arxiv_org_abs_2106_02509
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle Efficient ground state preparation in variational quantum eigensolver with symmetry-breaking layers
Park, Chae-Yeun
Quantum Physics
Statistical Mechanics
Variational quantum eigensolver (VQE) solves the ground state problem of a given Hamiltonian by finding the parameters of a quantum circuit ansatz that minimizes the Hamiltonian expectation value. Among possible quantum circuit ansätze, the Hamiltonian variational ansatz (HVA) is widely studied for quantum many-body problems as the ansatz with sufficiently large depth is theoretically guaranteed to express the ground state. However, since the HVA shares the same symmetry with the Hamiltonian, it is not necessarily good at finding the symmetry-broken ground states that prevail in nature. In this paper, we systematically explore the limitations of the HVA for solving symmetry-broken systems and propose an alternative quantum circuit ansatz with symmetry-breaking layers. With extensive numerical simulations, we show that the proposed ansatz finds the ground state in depth significantly shorter than the bare HVA when the target Hamiltonian has symmetry-broken ground states.
title Efficient ground state preparation in variational quantum eigensolver with symmetry-breaking layers
topic Quantum Physics
Statistical Mechanics
url https://arxiv.org/abs/2106.02509