Investigating Stark many-body localization with continuous unitary transformation flows

We investigate the ergodicity-to-localization transition in interacting fermion systems subjected to a spatially uniform electric field. For that, we employ the recently proposed tensorflow equations (TFE), a type of continuous unitary flow equations. This enables us to iteratively determine an appr...

Full description

Saved in:
Bibliographic Details
Main Authors: Jan-Niklas Herre, Qiyu Liu, Roman Rausch, Christoph Karrasch, Dante M. Kennes
Format: Article
Language:English
Published: American Physical Society 2025-07-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/wrtc-vzhl
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850119087962718208
author Jan-Niklas Herre
Qiyu Liu
Roman Rausch
Christoph Karrasch
Dante M. Kennes
author_facet Jan-Niklas Herre
Qiyu Liu
Roman Rausch
Christoph Karrasch
Dante M. Kennes
author_sort Jan-Niklas Herre
collection DOAJ
description We investigate the ergodicity-to-localization transition in interacting fermion systems subjected to a spatially uniform electric field. For that, we employ the recently proposed tensorflow equations (TFE), a type of continuous unitary flow equations. This enables us to iteratively determine an approximate diagonal basis of the quantum many-body system. We present improvements to the method, which achieves good accuracy at small to intermediate interaction strengths, even in the absence of an electric field or disorder. Then, we examine two quantities that reveal the fate of Stark MBL in 1D and 2D. First, we investigate the structure of the resulting basis to determine the crossover between ergodic and localized regimes with respect to electric field strength. Second, we simulate long-time dynamics at infinite temperature. Our results in 1D show a localization transition at nonzero field for finite interaction that vanishes with increasing system size leading to localization at infinitesimally small field even in the presence of interactions. In 2D, we find less clear signatures of localization and strong finite-size effects. We establish that the TFE work accurately up to intermediate times but cannot capture higher order effects in interaction strength that lead to delocalization at longer times in finite-size Stark MBL systems.
format Article
id doaj-art-78d047469a2a40279ba06183e26d7a4a
institution OA Journals
issn 2643-1564
language English
publishDate 2025-07-01
publisher American Physical Society
record_format Article
series Physical Review Research
spelling doaj-art-78d047469a2a40279ba06183e26d7a4a2025-08-20T02:35:43ZengAmerican Physical SocietyPhysical Review Research2643-15642025-07-017303304710.1103/wrtc-vzhlInvestigating Stark many-body localization with continuous unitary transformation flowsJan-Niklas HerreQiyu LiuRoman RauschChristoph KarraschDante M. KennesWe investigate the ergodicity-to-localization transition in interacting fermion systems subjected to a spatially uniform electric field. For that, we employ the recently proposed tensorflow equations (TFE), a type of continuous unitary flow equations. This enables us to iteratively determine an approximate diagonal basis of the quantum many-body system. We present improvements to the method, which achieves good accuracy at small to intermediate interaction strengths, even in the absence of an electric field or disorder. Then, we examine two quantities that reveal the fate of Stark MBL in 1D and 2D. First, we investigate the structure of the resulting basis to determine the crossover between ergodic and localized regimes with respect to electric field strength. Second, we simulate long-time dynamics at infinite temperature. Our results in 1D show a localization transition at nonzero field for finite interaction that vanishes with increasing system size leading to localization at infinitesimally small field even in the presence of interactions. In 2D, we find less clear signatures of localization and strong finite-size effects. We establish that the TFE work accurately up to intermediate times but cannot capture higher order effects in interaction strength that lead to delocalization at longer times in finite-size Stark MBL systems.http://doi.org/10.1103/wrtc-vzhl
spellingShingle Jan-Niklas Herre
Qiyu Liu
Roman Rausch
Christoph Karrasch
Dante M. Kennes
Investigating Stark many-body localization with continuous unitary transformation flows
Physical Review Research
title Investigating Stark many-body localization with continuous unitary transformation flows
title_full Investigating Stark many-body localization with continuous unitary transformation flows
title_fullStr Investigating Stark many-body localization with continuous unitary transformation flows
title_full_unstemmed Investigating Stark many-body localization with continuous unitary transformation flows
title_short Investigating Stark many-body localization with continuous unitary transformation flows
title_sort investigating stark many body localization with continuous unitary transformation flows
url http://doi.org/10.1103/wrtc-vzhl
work_keys_str_mv AT janniklasherre investigatingstarkmanybodylocalizationwithcontinuousunitarytransformationflows
AT qiyuliu investigatingstarkmanybodylocalizationwithcontinuousunitarytransformationflows
AT romanrausch investigatingstarkmanybodylocalizationwithcontinuousunitarytransformationflows
AT christophkarrasch investigatingstarkmanybodylocalizationwithcontinuousunitarytransformationflows
AT dantemkennes investigatingstarkmanybodylocalizationwithcontinuousunitarytransformationflows