Temperature-induced resonances and Landau damping of collective modes in Bose-Einstein condensed gases in spherical traps

TL;DR

This paper investigates how temperature affects collective oscillations in spherical Bose-Einstein condensates, focusing on resonances and Landau damping using perturbation theory and linearized Gross-Pitaevskii equations.

Contribution

It introduces a method to analyze temperature-induced resonances and damping in BECs with spherical symmetry, advancing understanding of thermal effects on collective modes.

Findings

Resonances occur at specific temperatures due to thermal excitations.

Landau damping significantly influences the decay of collective oscillations.

External perturbations can induce measurable resonances in the condensate.

Abstract

Interaction between collective monopole oscillations of a trapped Bose-Einstein condensate and thermal excitations is investigated by means of perturbation theory. We assume spherical symmetry to calculate the matrix elements by solving the linearized Gross-Pitaevskii equations. We use them to study the resonances of the condensate induced by temperature when an external perturbation of the trapping frequency is applied and to calculate the Landau damping of the oscillations.