Abstract： We investigate the collective modes of a quasi-two-dimensional (Q2D) superfluid Fermi gas in Bardeen--Cooper--Schrieffer Bose--Einstein condensation (BCS-BEC) crossover. For solving a generalized Gross--Pitaevskii equation by using a time-dependent variational method, we take a trial wavefunction with the form of hybrid Gaussian-parabolic type, which not only reflects the Q2D character of the system and also allows an essentially analytical approach of the problem. We present a Q2D criterion that is valid for various superfluid regimes and displays clearly the relation between the maximum condensed particle number and the parameters of trapping potential as well as atom--atom interaction. We show that due to the small particle number in the Q2D condensate, the contribution to oscillating frequencies by the quantum pressure in the strong confinement direction is significant and hence a Thomas--Fermi approximation can not be used.
ZHOU Yu;MA Xiao-Dong;HUANG Guo-Xiang. Collective Modes of a Quasi-Two-Dimensional Superfluid Fermi Gas in BCS-BEC Crossover[J]. 中国物理快报, 2006, 23(10): 2662-2665.
ZHOU Yu, MA Xiao-Dong, HUANG Guo-Xiang. Collective Modes of a Quasi-Two-Dimensional Superfluid Fermi Gas in BCS-BEC Crossover. Chin. Phys. Lett., 2006, 23(10): 2662-2665.
2006, Vol. 23 
