Collective excitations in a fermion-fermion mixture with different Fermi surfaces

Abstract

In this paper, collective excitations in a homogeneous fermion-fermion mixture with different Fermi surfaces are studied. In the Fermi liquid phase, the zero-sound velocity is found to be larger than the largest Fermi velocity. With attractive interactions, the superfluid phase appears below a critical temperature, and the phase mode is the low-energy collective excitation. The velocity of the phase mode is proportional to the geometric mean of the two Fermi velocities. The difference between the two velocities may serve as a tool to detect the superfluid phase.

4 pages. To be published in Phys. Rev. A

References in corpus (5)

• Observation of a Strongly-Interacting Degenerate Fermi Gas of Atoms
• Resonant control of elastic collisions in an optically trapped Fermi gas of atoms
• Low energy Collective Modes of a Superfluid Trapped atomic Fermi Gas
• Collective Modes of Trapped Fermi Gases in the Normal Phase
• Effects of the trapping potential on a superfluid atomic Fermi Gas