Papic, Z, Stoudenmire, EM and Abanin, DA (2015) Many-body localization in disorder-free systems: The importance of finite-size constraints. Annals of Physics, 362. pp. 714-725. ISSN 0003-4916
Abstract
Recently it has been suggested that many-body localization (MBL) can occur in translation-invariant systems, and candidate 1D models have been proposed. We find that such models, in contrast to MBL systems with quenched disorder, typically exhibit much more severe finite-size effects due to the presence of two or more vastly different energy scales. In a finite system, this can artificially split the density of states (DOS) into bands separated by large gaps. We argue for such models to faithfully represent the thermodynamic limit behavior, the ratio of relevant coupling must exceed a certain system-size depedent cutoff, chosen such that various bands in the DOS overlap one another. Setting the parameters this way to minimize finite-size effects, we study several translation-invariant MBL candidate models using exact diagonalization. Based on diagnostics including entanglement and local observables, we observe thermal (ergodic), rather than MBL-like behavior. Our results suggest that MBL in translation-invariant systems with two or more very different energy scales is less robust than perturbative arguments suggest, possibly pointing to the importance of non-perturbative effects which induce delocalization in the thermodynamic limit.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015, Elsevier Ltd. This is an author produced version of a paper published in Annals of Physics. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Many-body localization; Ergodicity breaking; Non-equilibrium quantum dynamics; Entanglement; Hubbard model; Exact diagonalization |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Theoretical Physics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 21 Jan 2016 12:37 |
Last Modified: | 16 Nov 2016 14:14 |
Published Version: | http://dx.doi.org/10.1016/j.aop.2015.08.024 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.aop.2015.08.024 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:93922 |