Dynamics of a trapped ultracold two-dimensional atomic gas

David Guéry-Odelin (1) , Thierry Lahaye (1)

1 LKB (Lhomond) - Laboratoire Kastler Brossel

This article is devoted to the study of two-dimensional Bose gases harmonically confined. We first summarize their equilibrium properties. For such a gas above the critical temperature, we also derive the frequencies and the damping of the collective oscillations and we investigate its expansion after releasing of the trap. The method is well suited to study the collisional effects taking place in the system and in particular to discuss the crossover between the hydrodynamic and the collisionless regimes. We establish the link between the relaxation times relevant for the damping of the collective oscillations and for the time-of-flight expansion. We also evaluate the collision rate and its relationship with the relaxation time.

Mots clés: Low-dimensional gas; Collective oscillations; Time of flight

Domaines: Autre [cond-mat.other]

David Guéry-Odelin, Thierry Lahaye. Dynamics of a trapped ultracold two-dimensional atomic gas. Comptes Rendus. Physique, 2004, 5, pp.55-63. ⟨hal-00002229⟩