Collective oscillations in ultracold atomic gases

TL;DR

This paper explores the fundamental oscillations and wave phenomena in ultracold atomic gases, revealing hybrid plasma-acoustic modes, resonance behaviors, and damping processes through fluid and kinetic models.

Contribution

It introduces the concept of hybrid plasma-acoustic modes in ultracold gases and analyzes their resonances and damping mechanisms using combined fluid and kinetic descriptions.

Findings

Identification of hybrid plasma-acoustic modes

Analysis of Tonks-Dattner resonances in spherical clouds

Discussion of Landau damping and nonlinear coupling

Abstract

Using both fluid and kinetic descriptions, where repulsive forces between near by atoms are included, we discuss the basic oscillations and waves of a cloud of ultra-cold atoms confined in a magneto-optical trap. The existence of a hybrid mode, with properties similar to both plasma and acoustic waves is described in detail. Tonks-Dattner resonances for confined hybrid modes in a spherical cloud are discussed and the prediction of a nonlinear coupling between the dipole resonanc and the hybrid modes is considered. Landau damping processes and quasi-linear diffusion in velocity space are also discussed.