Bloch theorem in the presence of an additional conserved charge
The Bloch theorem is a general theorem restricting the persistent current associated with a conserved U(1) charge in a ground state or in a thermal equilibrium. It gives an upper bound of the magnitude of the current density, which is inversely proportional to the system size. In a recent paper, Els...
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Format: | Article |
Language: | English |
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American Physical Society
2022-01-01
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Series: | Physical Review Research |
Online Access: | http://doi.org/10.1103/PhysRevResearch.4.013043 |
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author | Haruki Watanabe |
author_facet | Haruki Watanabe |
author_sort | Haruki Watanabe |
collection | DOAJ |
description | The Bloch theorem is a general theorem restricting the persistent current associated with a conserved U(1) charge in a ground state or in a thermal equilibrium. It gives an upper bound of the magnitude of the current density, which is inversely proportional to the system size. In a recent paper, Else and Senthil applied the argument for the Bloch theorem to a generalized Gibbs ensemble, assuming the presence of an additional conserved charge, and predicted a nonzero current density in the nonthermal steady state [Else and Senthil, Phys. Rev. B 104, 205132 (2021)2469-995010.1103/PhysRevB.104.205132]. In this paper, we provide a complementary derivation based on the canonical ensemble, given that the additional charge is strictly conserved within the system by itself. Furthermore, using the example where the additional conserved charge is the momentum operator, we discuss that the persistent current tends to vanish when the system is in contact with an external momentum reservoir in the comoving frame of the reservoir. |
first_indexed | 2024-04-24T10:17:08Z |
format | Article |
id | doaj.art-458fe530132045a9af82c55125fbaa76 |
institution | Directory Open Access Journal |
issn | 2643-1564 |
language | English |
last_indexed | 2024-04-24T10:17:08Z |
publishDate | 2022-01-01 |
publisher | American Physical Society |
record_format | Article |
series | Physical Review Research |
spelling | doaj.art-458fe530132045a9af82c55125fbaa762024-04-12T17:17:19ZengAmerican Physical SocietyPhysical Review Research2643-15642022-01-014101304310.1103/PhysRevResearch.4.013043Bloch theorem in the presence of an additional conserved chargeHaruki WatanabeThe Bloch theorem is a general theorem restricting the persistent current associated with a conserved U(1) charge in a ground state or in a thermal equilibrium. It gives an upper bound of the magnitude of the current density, which is inversely proportional to the system size. In a recent paper, Else and Senthil applied the argument for the Bloch theorem to a generalized Gibbs ensemble, assuming the presence of an additional conserved charge, and predicted a nonzero current density in the nonthermal steady state [Else and Senthil, Phys. Rev. B 104, 205132 (2021)2469-995010.1103/PhysRevB.104.205132]. In this paper, we provide a complementary derivation based on the canonical ensemble, given that the additional charge is strictly conserved within the system by itself. Furthermore, using the example where the additional conserved charge is the momentum operator, we discuss that the persistent current tends to vanish when the system is in contact with an external momentum reservoir in the comoving frame of the reservoir.http://doi.org/10.1103/PhysRevResearch.4.013043 |
spellingShingle | Haruki Watanabe Bloch theorem in the presence of an additional conserved charge Physical Review Research |
title | Bloch theorem in the presence of an additional conserved charge |
title_full | Bloch theorem in the presence of an additional conserved charge |
title_fullStr | Bloch theorem in the presence of an additional conserved charge |
title_full_unstemmed | Bloch theorem in the presence of an additional conserved charge |
title_short | Bloch theorem in the presence of an additional conserved charge |
title_sort | bloch theorem in the presence of an additional conserved charge |
url | http://doi.org/10.1103/PhysRevResearch.4.013043 |
work_keys_str_mv | AT harukiwatanabe blochtheoreminthepresenceofanadditionalconservedcharge |