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On the possibility of many-body localization in a doped Mott insulator
Many-body localization (MBL) is currently a hot issue of interacting systems, in which quantum mechanics overcomes thermalization of statistical mechanics. Like Anderson localization of non-interacting electrons, disorders are usually crucial in engineering the quantum interference in MBL. For trans...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5067514/ https://www.ncbi.nlm.nih.gov/pubmed/27752064 http://dx.doi.org/10.1038/srep35208 |
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author | He, Rong-Qiang Weng, Zheng-Yu |
author_facet | He, Rong-Qiang Weng, Zheng-Yu |
author_sort | He, Rong-Qiang |
collection | PubMed |
description | Many-body localization (MBL) is currently a hot issue of interacting systems, in which quantum mechanics overcomes thermalization of statistical mechanics. Like Anderson localization of non-interacting electrons, disorders are usually crucial in engineering the quantum interference in MBL. For translation invariant systems, however, the breakdown of eigenstate thermalization hypothesis due to a pure many-body quantum effect is still unclear. Here we demonstrate a possible MBL phenomenon without disorder, which emerges in a lightly doped Hubbard model with very strong interaction. By means of density matrix renormalization group numerical calculation on a two-leg ladder, we show that whereas a single hole can induce a very heavy Nagaoka polaron, two or more holes will form bound pair/droplets which are all localized excitations with flat bands at low energy densities. Consequently, MBL eigenstates of finite energy density can be constructed as composed of these localized droplets spatially separated. We further identify the underlying mechanism for this MBL as due to a novel ‘Berry phase’ of the doped Mott insulator, and show that by turning off this Berry phase either by increasing the anisotropy of the model or by hand, an eigenstate transition from the MBL to a conventional quasiparticle phase can be realized. |
format | Online Article Text |
id | pubmed-5067514 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Nature Publishing Group |
record_format | MEDLINE/PubMed |
spelling | pubmed-50675142016-10-26 On the possibility of many-body localization in a doped Mott insulator He, Rong-Qiang Weng, Zheng-Yu Sci Rep Article Many-body localization (MBL) is currently a hot issue of interacting systems, in which quantum mechanics overcomes thermalization of statistical mechanics. Like Anderson localization of non-interacting electrons, disorders are usually crucial in engineering the quantum interference in MBL. For translation invariant systems, however, the breakdown of eigenstate thermalization hypothesis due to a pure many-body quantum effect is still unclear. Here we demonstrate a possible MBL phenomenon without disorder, which emerges in a lightly doped Hubbard model with very strong interaction. By means of density matrix renormalization group numerical calculation on a two-leg ladder, we show that whereas a single hole can induce a very heavy Nagaoka polaron, two or more holes will form bound pair/droplets which are all localized excitations with flat bands at low energy densities. Consequently, MBL eigenstates of finite energy density can be constructed as composed of these localized droplets spatially separated. We further identify the underlying mechanism for this MBL as due to a novel ‘Berry phase’ of the doped Mott insulator, and show that by turning off this Berry phase either by increasing the anisotropy of the model or by hand, an eigenstate transition from the MBL to a conventional quasiparticle phase can be realized. Nature Publishing Group 2016-10-18 /pmc/articles/PMC5067514/ /pubmed/27752064 http://dx.doi.org/10.1038/srep35208 Text en Copyright © 2016, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
spellingShingle | Article He, Rong-Qiang Weng, Zheng-Yu On the possibility of many-body localization in a doped Mott insulator |
title | On the possibility of many-body localization in a doped Mott insulator |
title_full | On the possibility of many-body localization in a doped Mott insulator |
title_fullStr | On the possibility of many-body localization in a doped Mott insulator |
title_full_unstemmed | On the possibility of many-body localization in a doped Mott insulator |
title_short | On the possibility of many-body localization in a doped Mott insulator |
title_sort | on the possibility of many-body localization in a doped mott insulator |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5067514/ https://www.ncbi.nlm.nih.gov/pubmed/27752064 http://dx.doi.org/10.1038/srep35208 |
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