Thermalization of an Oscillating Bose Condensate in a Disordered Trap

Che Hsiu Hsueh, Makoto Tsubota, Wen Chin Wu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


Previously, we numerically showed that thermalization can occur in an oscillating Bose–Einstein condensate with a disordered harmonic trap when the healing length ξ of the condensate is shorter than the correlation length σD of the Gaussian disorder [see, for example, the experiment reported in Dries et al. (Phys Rev A 82:033603, 2010)]. In this work, we investigate and show that in the ξ> σD (Anderson localization) regime, the system can also exhibit a relaxation process from nonequilibrium to equilibrium. In such an isolated quantum system, energy and particle number are conserved and the irreversible evolution toward thermodynamic equilibrium is induced by the disorder. The thermodynamic equilibrium is evidenced by the maximized entropy S[ nk] in which the waveaction spectrum nk follows the Rayleigh–Jeans distribution. Besides, unlike a monotonic irreversible process of thermalization to equilibrium, the Fermi–Pasta–Ulam–Tsingou recurrence arises in this system, manifested by the oscillation of the nonequilibrium entropy.

Original languageEnglish
Pages (from-to)13-20
Number of pages8
JournalJournal of Low Temperature Physics
Issue number1-2
Publication statusPublished - 2019 Jul 15


  • Anderson localization
  • Disorder
  • Irreversible process
  • Thermalization

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • General Materials Science
  • Condensed Matter Physics


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