Breathing mode of rapidly rotating Bose-Einstein condensates
Abstract
We show that the breathing mode of a rapidly-rotating, harmonically-trapped Bose-Einstein condensate may be described by a generalized lowest Landau level (LLL) wave function, in which the oscillator length is treated as a variable. Using this wave function in a variational Lagrangian formalism, we show that the frequency of the breathing mode for a two-dimensional cloud is , where is the trap frequency. We also study large-amplitude oscillations and confirm that the above result is not limited to linear oscillations. The resulting mode frequency can be understood in terms of orbits of a single particle in a harmonic trap. The mode frequency is also calculated for a cloud in three dimensions and the result for the axial breathing mode frequency agrees with recent experimental data in the rapid rotation regime.
Cite
@article{arxiv.cond-mat/0506331,
title = {Breathing mode of rapidly rotating Bose-Einstein condensates},
author = {Gentaro Watanabe},
journal= {arXiv preprint arXiv:cond-mat/0506331},
year = {2007}
}
Comments
10 pages, 3 figures. Extended discussion. see also cond-mat/0512317. Accepted for publication in Phys. Rev. A, one reference added