Macroscopic dynamics of a Bose-Einstein condensate containing a vortex lattice

TL;DR

This paper models the large-scale behavior of a rotating Bose-Einstein condensate with many vortices, analyzing its stationary states, collective excitations, expansion dynamics, and response to trap deformations, aligning with recent experimental findings.

Contribution

It provides a macroscopic hydrodynamic framework to understand vortex lattice dynamics in Bose-Einstein condensates, extending previous microscopic models.

Findings

Stationary vortex configurations depend on angular velocity.

Collective excitation frequencies vary with vortex lattice rotation.

Condensate expansion dynamics match experimental observations.

Abstract

Starting from the equations of rotational hydrodynamics we study the macroscopic behaviour of a trapped Bose-Einstein condensate containing a large number of vortices. The stationary configurations of the system, the frequencies of the collective excitations and the expansion of the condensate are investigated as a function of the angular velocity of the vortex lattice. The time evolution of the condensate and of the lattice geometry induced by a sudden deformation of the trap is also discussed and compared with the recent experimental results of P. Engels et al., Phys. Rev. Lett. 89, 100403 (2002).