A Query-based Quantum Eigensolver

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Jin, Shan, Wu, Shaojun, Zhou, Guanyu, Li, Ying, Li, Lvzhou, Li, Bo, Wang, Xiaoting
Natura: Preprint
Pubblicazione: 2020
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866917932179652608
author Jin, Shan
Wu, Shaojun
Zhou, Guanyu
Li, Ying
Li, Lvzhou
Li, Bo
Wang, Xiaoting
author_facet Jin, Shan
Wu, Shaojun
Zhou, Guanyu
Li, Ying
Li, Lvzhou
Li, Bo
Wang, Xiaoting
contents Solving eigenvalue problems is crucially important for both classical and quantum applications. Many well-known numerical eigensolvers have been developed, including the QR and the power methods for classical computers, as well as the quantum phase estimation(QPE) method and the variational quantum eigensolver for quantum computers. In this work, we present an alternative type of quantum method that uses fixed-point quantum search to solve Type II eigenvalue problems. It serves as an important complement to the QPE method, which is a Type I eigensolver. We find that the effectiveness of our method depends crucially on the appropriate choice of the initial state to guarantee a sufficiently large overlap with the unknown target eigenstate. We also show that the quantum oracle of our query-based method can be efficiently constructed for efficiently-simulated Hamiltonians, which is crucial for analyzing the total gate complexity. In addition, compared with the QPE method, our query-based method achieves a quadratic speedup in solving Type II problems.
format Preprint
id arxiv_https___arxiv_org_abs_2008_00594
institution arXiv
publishDate 2020
record_format arxiv
spellingShingle A Query-based Quantum Eigensolver
Jin, Shan
Wu, Shaojun
Zhou, Guanyu
Li, Ying
Li, Lvzhou
Li, Bo
Wang, Xiaoting
Quantum Physics
Solving eigenvalue problems is crucially important for both classical and quantum applications. Many well-known numerical eigensolvers have been developed, including the QR and the power methods for classical computers, as well as the quantum phase estimation(QPE) method and the variational quantum eigensolver for quantum computers. In this work, we present an alternative type of quantum method that uses fixed-point quantum search to solve Type II eigenvalue problems. It serves as an important complement to the QPE method, which is a Type I eigensolver. We find that the effectiveness of our method depends crucially on the appropriate choice of the initial state to guarantee a sufficiently large overlap with the unknown target eigenstate. We also show that the quantum oracle of our query-based method can be efficiently constructed for efficiently-simulated Hamiltonians, which is crucial for analyzing the total gate complexity. In addition, compared with the QPE method, our query-based method achieves a quadratic speedup in solving Type II problems.
title A Query-based Quantum Eigensolver
topic Quantum Physics
url https://arxiv.org/abs/2008.00594