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Title: Quantum quench dynamics of the Bose-Hubbard model at finite temperatures

Abstract

We study quench dynamics of the Bose-Hubbard model by exact diagonalization. Initially, the system is at thermal equilibrium and of a finite temperature. The system is then quenched by changing the on-site interaction strength U suddenly. Both the single-quench and double-quench scenarios are considered. In the former case, the time-averaged density matrix and the real-time evolution are investigated. It is found that though the system thermalizes only in a very narrow range of the quenched value of U, it does equilibrate or relax well into a much larger range. Most importantly, it is proven that this is guaranteed for some typical observables in the thermodynamic limit. In order to test whether it is possible to distinguish the unitarily evolving density matrix from the time-averaged (thus time-independent), fully decohered density matrix, a second quench is considered. It turns out that the answer is affirmative or negative depending on whether the intermediate value of U is zero or not.

Authors:
 [1];  [2];  [1]
  1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China)
  2. FOCUS Center and MCTP, Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)
Publication Date:
OSTI Identifier:
21550167
Resource Type:
Journal Article
Journal Name:
Physical Review. A
Additional Journal Information:
Journal Volume: 83; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevA.83.063622; (c) 2011 American Institute of Physics; Journal ID: ISSN 1050-2947
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DENSITY MATRIX; DYNAMICS; HUBBARD MODEL; INTERACTIONS; QUANTUM MECHANICS; TEMPERATURE DEPENDENCE; THERMAL EQUILIBRIUM; THERMALIZATION; TIME DEPENDENCE; CRYSTAL MODELS; EQUILIBRIUM; MATHEMATICAL MODELS; MATRICES; MECHANICS; SLOWING-DOWN

Citation Formats

Zhang, J M, FOCUS Center and MCTP, Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, Shen, C, and Liu, W M. Quantum quench dynamics of the Bose-Hubbard model at finite temperatures. United States: N. p., 2011. Web. doi:10.1103/PHYSREVA.83.063622.
Zhang, J M, FOCUS Center and MCTP, Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, Shen, C, & Liu, W M. Quantum quench dynamics of the Bose-Hubbard model at finite temperatures. United States. https://doi.org/10.1103/PHYSREVA.83.063622
Zhang, J M, FOCUS Center and MCTP, Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, Shen, C, and Liu, W M. 2011. "Quantum quench dynamics of the Bose-Hubbard model at finite temperatures". United States. https://doi.org/10.1103/PHYSREVA.83.063622.
@article{osti_21550167,
title = {Quantum quench dynamics of the Bose-Hubbard model at finite temperatures},
author = {Zhang, J M and FOCUS Center and MCTP, Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 and Shen, C and Liu, W M},
abstractNote = {We study quench dynamics of the Bose-Hubbard model by exact diagonalization. Initially, the system is at thermal equilibrium and of a finite temperature. The system is then quenched by changing the on-site interaction strength U suddenly. Both the single-quench and double-quench scenarios are considered. In the former case, the time-averaged density matrix and the real-time evolution are investigated. It is found that though the system thermalizes only in a very narrow range of the quenched value of U, it does equilibrate or relax well into a much larger range. Most importantly, it is proven that this is guaranteed for some typical observables in the thermodynamic limit. In order to test whether it is possible to distinguish the unitarily evolving density matrix from the time-averaged (thus time-independent), fully decohered density matrix, a second quench is considered. It turns out that the answer is affirmative or negative depending on whether the intermediate value of U is zero or not.},
doi = {10.1103/PHYSREVA.83.063622},
url = {https://www.osti.gov/biblio/21550167}, journal = {Physical Review. A},
issn = {1050-2947},
number = 6,
volume = 83,
place = {United States},
year = {Wed Jun 15 00:00:00 EDT 2011},
month = {Wed Jun 15 00:00:00 EDT 2011}
}