Indexed on: 05 Sep '14Published on: 05 Sep '14Published in: Journal of low temperature physics
We investigate the collective excitations of a one-dimensional ultracold Fermi gas in the crossover from a Bardeen–Cooper–Schrieffer superfluid to a Bose-Einstein condensate. The trap we consider is a quadratic plus quartic potential in view of the relevant experimental conditions. Using variational approaches, the coupled equations of motions for the center-of-mass coordinate of the Superfluid Fermi gas and its width are derived. Then, two low-energy excitation modes are obtained analytically. The frequency shift induced by the anharmonic distortion, and the collapse and revival of the collective excitations originating from the nonlinear coupling between the two modes are discussed.