Puschmann, Martin 
; Getelina, João C. ; Hoyos, José A. ; Vojta, Thomas
Alternative links to fulltext:Arxiv Full text not available from this repository.
| Item type: | Article |
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| Journal or Publication Title: | arXiv |
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| Date: | 26 January 2021 |
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| Institutions: | Physics > Institute of Theroretical Physics > Chair Ferdinand Evers |
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| Identification Number: | | Value | Type |
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| 2101.11065 | arXiv ID |
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| Related URLs: | |
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| Keywords: | quantum phase transition, disorder, collective excitation, superfluid, localization |
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| Dewey Decimal Classification: | 500 Science > 530 Physics |
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| Status: | Published |
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| Refereed: | Yes, this version has been refereed |
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| Created at the University of Regensburg: | Partially |
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| Item ID: | 45946 |
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Inhomogeneous mean-field approach to collective excitations in disordered interacting bosons. (Deposited on 08 Jun 2021 05:53)
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Abstract
We develop an inhomogeneous quantum mean-field theory for disordered particle-hole symmetric Bose-Hubbard models in two dimensions. Collective excitations are described by fluctuations about the mean-field ground state. In quadratic (Gaussian) approximation, the Goldstone (phase) and Higgs (amplitude) modes completely decouple. Each is described by a disordered Bogoliubov Hamiltonian which can be ...
Abstract
We develop an inhomogeneous quantum mean-field theory for disordered particle-hole symmetric Bose-Hubbard models in two dimensions. Collective excitations are described by fluctuations about the mean-field ground state. In quadratic (Gaussian) approximation, the Goldstone (phase) and Higgs (amplitude) modes completely decouple. Each is described by a disordered Bogoliubov Hamiltonian which can be solved by an inhomogeneous multi-mode Bogoliubov transformation. We find that the Higgs modes are noncritical and strictly
localized everywhere in the phase diagram. In contrast, the lowest-energy Goldstone mode delocalizes in the superfluid phase. We discuss these findings from the perspective of conventional Anderson localization theory. We also compare the effects of different types of disorder such as site dilution and random interactions; we relate our results to recent quantum Monte Carlo simulations, and we discuss the limits and generality of our approach.
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