Europhys. Lett.
Volume 68, Number 6, December 2004
Page(s) 762 - 768
Section General
Published online 17 November 2004
Europhys. Lett., 68 (6), pp. 762-768 (2004)
DOI: 10.1209/epl/i2004-10281-7

Axial collective excitations of a degenerate Fermi gas in the BEC to unitarity crossover

R. Combescot and X. Leyronas

Laboratoire de Physique Statistique, Ecole Normale Supérieure 24 rue Lhomond, 75231 Paris Cedex 05, France

received 28 July 2004; accepted in final form 14 October 2004
published online 17 November 2004

We show that, with reasonable hypotheses leading to a simple modeling, a link can be obtained from experiments on the axial low-frequency collective modes between the ratio $a_{\ab{M}}/a$, of the molecular scattering length $a_{\ab{M}}$ to the atomic scattering length, and the energy parameter $\xi\equiv 1+\beta$ of the gas at the unitarity limit. We also point out that, in order to reach the range where the features of the Bose limit can be clearly seen, experiments have to go to more dilute situations than have been achieved presently.

05.30.Fk - Fermion systems and electron gas.
32.80.Pj - Optical cooling of atoms; trapping.
47.37.+q - Hydrodynamic aspects of superfluidity.

© EDP Sciences 2004