Berry Phase Effects on Dynamics of Quasiparticles in a Superfluid with a Vortex

TL;DR

This paper investigates how Berry phase effects influence quasiparticle dynamics in a superfluid with a vortex, revealing modifications to quasiparticle behavior and proposing an experiment to observe these effects.

Contribution

It demonstrates the impact of Berry phase on quasiparticle statistics and thermodynamics in superfluids with vortices, a novel insight in superfluid physics.

Findings

Berry phase alters canonical relations between momentum and position

Total transverse force on vortex is proportional to superfluid density

Proposed experimental method to observe Berry phase effects

Abstract

We study quasiparticle dynamics in a Bose-Einstein condensate with a vortex by following the center of mass motion of a Bogoliubov wavepacket, and find important Berry phase effects due to the background flow. We show that Berry phase invalidates the usual canonical relation between the mechanical momentum and position variables, leading to important modifications of quasiparticle statistics and thermodynamic properties of the condensates. Applying these results to a vortex in an infinite uniform superfluid, we find that the total transverse force acting on the vortex is proportional to the superfluid density. We propose an experimental setup to directly observe Berry phase effects through measuring local thermal atoms momentum distribution around a vortex.