Interatomic collisions in a tightly confined Bose gas

D.S Petrov , G.V Shlyapnikov

We discuss pair interatomic collisions in a Bose gas tightly confined in one (axial) direction and identify two regimes of scattering. In the quasi2D regime, where the confinement frequency $\omega_0$ greatly exceeds the gas temperature $T$, the scattering rates exhibit 2D features of the particle motion. At temperatures $T\sim\hbar\omega_0$ one has a confinement-dominated 3D regime, where the confinement can change the momentum dependence of the scattering amplitudes. We describe the collision-induced energy exchange between the axial and radial degrees of freedom and analyze recent experiments on thermalization and spin relaxation rates in a tightly (axially) confined gas of Cs atoms.

Domaines: Mécanique statistique [cond-mat.stat-mech]

D.S Petrov, G.V Shlyapnikov. Interatomic collisions in a tightly confined Bose gas. Physical Review A : Atomic, molecular, and optical physics [1990-2015], 2001, 64, pp.012706. ⟨hal-00002133⟩