Quantum many-body scars as remnants of stable many-body periodic orbits

Fuente: arXiv
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Main Author: Omiya, Keita
Format: Preprint
Published: 2024
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author Omiya, Keita
author_facet Omiya, Keita
contents Quantum many-body scars (QMBS) represent a weak ergodicity-breaking phenomenon that defies the common scenario of thermalization in closed quantum systems. They are often regarded as a many-body analog of quantum scars (QS) -- a single-particle phenomenon in quantum chaos -- due to their superficial similarities. However, unlike QS, a clear connection between QMBS and classical chaos has remained elusive. It has nevertheless been speculated that in an appropriate semiclassical limit, QMBS should have a correspondence to weakly unstable periodic orbits. In this paper, I present a counterexample to this conjecture by studying a bosonic model with a large number of flavors. The dynamics of out-of-time-ordered correlators (OTOCs) suggest that QMBS do not display chaotic behavior in the semiclassical limit. In contrast, chaotic dynamics are expected for initial states not associated with QMBS. Interestingly, the anomalous OTOC dynamics persist even under weak perturbations that eliminate the scarred eigenstates, suggesting a certain robustness in the phenomenon.
format Preprint
id arxiv_https___arxiv_org_abs_2410_16916
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Quantum many-body scars as remnants of stable many-body periodic orbits
Omiya, Keita
Quantum Physics
Statistical Mechanics
Strongly Correlated Electrons
Quantum many-body scars (QMBS) represent a weak ergodicity-breaking phenomenon that defies the common scenario of thermalization in closed quantum systems. They are often regarded as a many-body analog of quantum scars (QS) -- a single-particle phenomenon in quantum chaos -- due to their superficial similarities. However, unlike QS, a clear connection between QMBS and classical chaos has remained elusive. It has nevertheless been speculated that in an appropriate semiclassical limit, QMBS should have a correspondence to weakly unstable periodic orbits. In this paper, I present a counterexample to this conjecture by studying a bosonic model with a large number of flavors. The dynamics of out-of-time-ordered correlators (OTOCs) suggest that QMBS do not display chaotic behavior in the semiclassical limit. In contrast, chaotic dynamics are expected for initial states not associated with QMBS. Interestingly, the anomalous OTOC dynamics persist even under weak perturbations that eliminate the scarred eigenstates, suggesting a certain robustness in the phenomenon.
title Quantum many-body scars as remnants of stable many-body periodic orbits
topic Quantum Physics
Statistical Mechanics
Strongly Correlated Electrons
url https://arxiv.org/abs/2410.16916