Finite-size effects in the dynamics of few bosons in a ring potential

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Abstract

We study the temporal evolution of a small number N of ultra-cold bosonic atoms confined in a ring potential. Assuming that initially the system is in a solitary-wave solution of the corresponding mean-field problem, we identify significant differences in the time evolution of the density distribution of the atoms when it instead is evaluated with the many-body Schrödinger equation. Three characteristic timescales are derived: the first is the period of rotation of the wave around the ring, the second is associated with a 'decay' of the density variation, and the third is associated with periodic 'collapses' and 'revivals' of the density variations, with a factor of separating each of them. The last two timescales tend to infinity in the appropriate limit of large N, in agreement with the mean-field approximation. These findings are based on the assumption of the initial state being a mean-field state. We confirm this behavior by comparison to the exact solutions for a few-body system stirred by an external potential. We find that the exact solutions of the driven system exhibit similar dynamical features.

Details

Authors
Organisations
External organisations
  • Selcuk University
  • Technological Educational Institute of Crete
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Atom and Molecular Physics and Optics

Keywords

  • exact diagonalization, few-body systems, quantum rings, time evolution
Original languageEnglish
Article number035504
JournalJournal of Physics B: Atomic, Molecular and Optical Physics
Volume51
Issue number3
Publication statusPublished - 2018 Jan 16
Publication categoryResearch
Peer-reviewedYes