Exact vortex nucleation and cooperative vortex tunneling in dilute BECs

TL;DR

This paper provides an exact many-body analysis of vortex nucleation in dilute Bose-Einstein condensates within the lowest Landau level, revealing non-mean field phenomena and cooperative vortex tunneling at large particle numbers.

Contribution

It introduces an exact analysis of vortex nucleation in dilute BECs in the LLL regime, highlighting non-mean field effects and vortex tunneling mechanisms.

Findings

Exposes non-mean field features at high filling factors.

Identifies exponential approach of energy levels near critical rotation.

Describes vortex tunneling dependence on system parameters.

Abstract

With the imminent advent of mesoscopic rotating BECs in the lowest Landau level (LLL) regime, we explore LLL vortex nucleation. An exact many-body analysis is presented in a weakly elliptical trap for up to 400 particles. Striking non-mean field features are exposed at filling factors >>1 . Eg near the critical rotation frequency pairs of energy levels approach each other with exponential accuracy. A physical interpretation is provided by requantising a mean field theory, where 1/N plays the role of Planck's constant, revealing two vortices cooperatively tunneling between classically degenerate energy minima. The tunnel splitting variation is described in terms of frequency, particle number and ellipticity.