Logarithmic spreading of out-of-time-ordered correlators without many-body localization
Abstract
Out-of-time-ordered correlators (OTOCs) describe information scrambling under unitary time evolution, and provide a useful probe of the emergence of quantum chaos. Here we calculate OTOCs for a model of disorder-free localization whose exact solubility allows us to study long-time behaviour in large systems. Remarkably, we observe logarithmic spreading of correlations, qualitatively different to both thermalizing and Anderson localized systems. Rather, such behaviour is normally taken as a signature of many-body localization, so that our findings for an essentially non-interacting model are surprising. We provide an explanation for this unusual behaviour, and suggest a novel Loschmidt echo protocol as a probe of correlation spreading. We show that the logarithmic spreading of correlations probed by this protocol is a generic feature of localized systems, with or without interactions.
Keywords
Cite
@article{arxiv.1812.07981,
title = {Logarithmic spreading of out-of-time-ordered correlators without many-body localization},
author = {Adam Smith and Johannes Knolle and Roderich Moessner and Dmitry L. Kovrizhin},
journal= {arXiv preprint arXiv:1812.07981},
year = {2019}
}
Comments
Published version - 5 pages, 4 figures (plus Sup. Mat. of 4 pages incl. 3 figures)