Quantum fluctuations and condensate fraction during the time-of-flight expansion
arXiv:0910.1518 · doi:10.1103/PhysRevA.82.031601
Abstract
The quantum fluctuation effects in the time-of-flight (TOF) experiment for a condensate released from an optical lattice potential is studied within the truncated Wigner approximation. By investigating both the spatial and momentum density distributions, we find that the condensate fraction decreases monotonically in time and hence cannot be measured in the standard TOF image. We then propose a semi-quantitative analysis for such dynamical quantum depletion process. Our study shows a universal algebraic decay of the true condensate fraction, and have a very good agreement with numerical results. We also discuss possible methods to determine the condensate fraction inside the optical lattice, and its implication to the TOF experiments in higher dimensional systems.
4 pages and 3 figures, the same as the published version
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Cited by in corpus (5)
- Phase space representation of quantum dynamics
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- One dimensional Bose-Einstein condensate under the effect of the extended uncertainty principle
- Global and local condensate and superfluid fraction of a few hard core bosons in a cubic optical lattice plus external harmonic confinement
- Expansion of a one-dimensional Bose gas: the role of interactions and kinetic-energy driving