Quantum algorithm for evaluating operator size with Bell measurements

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Hu, Xi-Dan, Luo, Tong, Zhang, Dan-Bo
Format: Preprint
Publié: 2022
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866916648619868160
author Hu, Xi-Dan
Luo, Tong
Zhang, Dan-Bo
author_facet Hu, Xi-Dan
Luo, Tong
Zhang, Dan-Bo
contents Operator size growth describes the scrambling of operators in quantum dynamics and stands out as an essential physical concept for characterizing quantum chaos. Important as it is, a scheme for direct measuring operator size on a quantum computer is still absent. Here, we propose a quantum algorithm for direct measuring the operator size and its distribution based on Bell measurement. The algorithm is verified with spin chains and meanwhile, the effects of Trotterization error and quantum noise are analyzed. It is revealed that saturation of operator size growth can be due to quantum chaos itself or be a consequence of quantum noises, which make a distinction between quantum integrable and chaotic systems difficulty on noisy quantum processors. Nevertheless, it is found that the error mitigation will effectively reduce the influence of noise, so as to restore the distinguishability of quantum chaotic systems. Our work provides a feasible protocol for investigating quantum chaos on noisy quantum computers by measuring operator size growth.
format Preprint
id arxiv_https___arxiv_org_abs_2209_10724
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Quantum algorithm for evaluating operator size with Bell measurements
Hu, Xi-Dan
Luo, Tong
Zhang, Dan-Bo
Quantum Physics
Computational Physics
Operator size growth describes the scrambling of operators in quantum dynamics and stands out as an essential physical concept for characterizing quantum chaos. Important as it is, a scheme for direct measuring operator size on a quantum computer is still absent. Here, we propose a quantum algorithm for direct measuring the operator size and its distribution based on Bell measurement. The algorithm is verified with spin chains and meanwhile, the effects of Trotterization error and quantum noise are analyzed. It is revealed that saturation of operator size growth can be due to quantum chaos itself or be a consequence of quantum noises, which make a distinction between quantum integrable and chaotic systems difficulty on noisy quantum processors. Nevertheless, it is found that the error mitigation will effectively reduce the influence of noise, so as to restore the distinguishability of quantum chaotic systems. Our work provides a feasible protocol for investigating quantum chaos on noisy quantum computers by measuring operator size growth.
title Quantum algorithm for evaluating operator size with Bell measurements
topic Quantum Physics
Computational Physics
url https://arxiv.org/abs/2209.10724