1210.1813 (Igor E. Mazets)

Two-dimensional dynamics of expansion of a degenerate Bose gas    [PDF]

Igor E. Mazets

Expansion of a degenerate Bose gas released from a pancake-like trap is numerically simulated under assumption of separation of motion in the plane of the loose initial trapping and the motion in the direction of the initial tight trapping. The initial conditions for the phase fluctuations are generated using the extension to the two-dimensional case of the description of the phase noise by the Ornstein-Uhlenbeck stochastic process. The numerical simulations, taking into account both the finite size of the two-dimensional system and the atomic interactions, which cannot be neglected on the early stage of expansion, did not reproduce the scaling law for the peaks in the density fluctuation spectra experimentally observed by Choi, Seo, Kwon, and Shin [Phys. Rev. Lett. 109, 125301 (2012)]. The latter experimental results results may thus require an explanation beyond our current assumptions.

View original: http://arxiv.org/abs/1210.1813