2018/07/29 by Che Hsiu Hsueh, Hsueh, Che-Hsiu, Makoto Tsubota +3
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Quantum Gases (cond-mat.quant-gas) #Quantum many-body systems #Strong Light-Matter Interactions
paper · pdf · doi:10.48550/arxiv.1807.11047
openalex publication_date 2018/07/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Previously we numerically showed that thermalization can occur in an oscillating Bose-Einstein condensate (BEC) with a disordered harmonic trap when healing length ξ of the condensate is shorter than the correlation length σD of the disorder [see, for example, the experiment reported in Phys. Rev. A 82, 033603 (2010)]. In this work, we investigate the weakly interacting or Anderson localization regime ξ>σD and show that the oscillating BEC 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 towards 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 non-equilibrium entropy.