Rapidly rotating Bose-Einstein condensates in anharmonic potentials

TL;DR

This paper investigates the phase transitions of rapidly rotating Bose-Einstein condensates in anharmonic traps, identifying various vortex configurations and mapping their phase diagram using a variational approach.

Contribution

It introduces an augmented Thomas-Fermi variational method to analyze vortex phases in strongly interacting condensates within anharmonic potentials.

Findings

Identification of vortex lattice, vortex lattice with a hole, and giant vortex phases.

Determination of phase transition boundaries between these vortex states.

Mapping of the zero-temperature phase diagram for such condensates.

Abstract

Rapidly rotating Bose-Einstein condensates confined in anharmonic traps can exhibit a rich variety of vortex phases, including a vortex lattice, a vortex lattice with a hole, and a giant vortex. Using an augmented Thomas-Fermi variational approach to determine the ground state of the condensate in the rotating frame -- valid for sufficiently strongly interacting condensates -- we determine the transitions between these three phases for a quadratic-plus-quartic confining potential. Combining the present results with previous numerical simulations of small rotating condensates in such anharmonic potentials, we delineate the general structure of the zero temperature phase diagram.