Vortex liquids and vortex quantum Hall states in trapped rotating Bose gases

TL;DR

This paper explores the formation of vortex quantum Hall states in rotating Bose gases, identifying phase transitions from vortex lattice to vortex liquid and ultimately to a quantum Hall state across varying rotation frequencies.

Contribution

It demonstrates the conditions under which vortex quantum Hall states can form in trapped Bose gases and describes the phase transitions involved.

Findings

Vortex lattice melts into vortex liquid at a critical rotation frequency.

Quantum Hall states coexist with vortex liquids in certain regions.

The entire system can become a particle quantum Hall state at higher rotation frequencies.

Abstract

We discuss the feasibility of quantum Hall states of vortices in trapped low-density two-dimensional Bose gases with large particle interactions. For interaction strengths larger than a critical dimensionless 2D coupling constant $g_c \approx 0.6$, upon increasing the rotation frequency, the system is shown to spatially separate into vortex lattice and melted vortex lattice (vortex liquid) phases. At a first critical frequency, the lattice melts completely, and strongly correlated vortex and particle quantum Hall liquids coexist in inner respectively outer regions of the gas cloud. Finally, at a second critical frequency, the vortex liquid disappears and the strongly correlated particle quantum Hall state fills the whole sample.