Microscopic description of the twist mode in normal and superfluid trapped Fermi gases
arXiv:cond-mat/0407475 · doi:10.1103/PhysRevA.71.013603
Abstract
We investigate the "twist" mode (rotation of the upper against the lower hemisphere) of a dilute atomic Fermi gas in a spherical trap. The normal and superfluid phases are considered. The linear response to this external perturbation is calculated within the microscopic Hartree-Fock-Bogoliubov approach. In the normal phase the excitation spectrum is concentrated in a rather narrow peak very close to the trapping frequency. In the superfluid phase the strength starts to be damped and fragmented and the collectivity of the mode is progressively lost when the temperature decreases. In the weak-pairing regime some reminiscence of the collective motion still exists, whereas in the strong-pairing regime the twist mode is completely washed out. The disappearance of the twist mode in the strong-pairing regime with decreasing temperature is interpreted in the framework of the two-fluid model.
arXiv commentrevtex4, 8 pages, 4 figures; v2: important changes (discussion, figures, appendix and one reference added)
References in corpus (17)
- Observation of a Strongly-Interacting Degenerate Fermi Gas of Atoms
- Evidence for Superfluidity in a Resonantly Interacting Fermi Gas
- Collective excitations of a degenerate gas at the BEC-BCS crossover
- Controlled Collapse of a Bose-Einstein Condensate
- The Superfluid State of Atomic Li6 in a Magnetic Trap
- Renormalization of the Hartree-Fock-Bogoliubov Equations in the Case of a Zero Range Pairing Interaction
- BCS Theory for Trapped Ultracold Fermions
- Pauli Blocking of Collisions in a Quantum Degenerate Atomic Fermi Gas
- Sympathetic cooling of bosonic and fermionic Lithium gases towards quantum degeneracy
- Low energy Collective Modes of a Superfluid Trapped atomic Fermi Gas
- Low energy collective excitations in a superfluid trapped Fermi gas
- Critical temperature and Ginzburg-Landau equation for a trapped Fermi gas
- Hartree-Fock-Bogoliubov theory versus local-density approximation for superfluid trapped fermionic atoms
- Moment of inertia of a trapped superfluid gas of atomic Fermions
- Slow rotation of a superfluid trapped Fermi gas
- Twist Mode in Spherical Alkali Metal Clusters
- The Twist Mode in Atomic Fermi Gases