Thermal and quantum fluctuations of confined Bose–Einstein condensate beyond the Bogoliubov approximation

Y. Nakamura, T. Kawaguchi, Y. Torii, Y. Yamanaka

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The formulation for zero mode of a Bose–Einstein condensate beyond the Bogoliubov approximation at zero temperature [Y. Nakamura et al., Phys. Rev. A 89 (2014) 013613] is extended to finite temperature. Both thermal and quantum fluctuations are considered in a manner consistent with a concept of spontaneous symmetry breakdown for a finite-size system. Therefore, we need a proper treatment of the zero mode operators, which invoke non-trivial enhancements in depletion condensate and thermodynamical quantities such as the specific heat. The enhancements are visible in the weak interaction case. Our approach reproduces the results of a homogeneous system in the Bogoliubov approximation in a large particle number limit.

Original languageEnglish
Pages (from-to)484-498
Number of pages15
JournalAnnals of Physics
Volume376
DOIs
Publication statusPublished - 2017 Jan 1

Keywords

  • Bose–Einstein condensation
  • Cold atom
  • Finite temperature
  • Quantum field theory
  • Spontaneous symmetry breaking
  • Zero mode

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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