摘要
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 Gaussianparabolic 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.
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 Gaussianparabolic 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.
基金
Supported by National Natural Science Foundation of China under Grant Nos 90403008 and 10434060.
