Vortices in Bose-Einstein condensates with anharmonic confinement

TL;DR

This paper studies vortices in a rotating Bose-Einstein condensate with anharmonic trapping, revealing phase transitions between different vortex states and establishing a universal phase diagram under specific limits.

Contribution

It provides a detailed analysis of the phase diagram for vortices in anharmonic traps, highlighting the universality and exactness in certain limits.

Findings

Phase transitions between multiply- and singly-quantized vortices.

Universal phase diagram in small anharmonicity and weak coupling limits.

Exact results in the specified limits.

Abstract

We examine an effectively repulsive Bose-Einstein condensate of atoms, that rotates in a quadratic-plus-quartic trapping potential. We investigate the phase diagram of the system as a function of the angular frequency of rotation and of the coupling constant, demonstrating that there are phase transitions between multiply- and singly-quantized vortex states. The derived phase diagram is shown to be universal and exact in the limits of small anharmonicity and weak coupling constant.