Cooperative Ring Exchange and Quantum Melting of Vortex Lattices in Atomic Bose-Einstein Condensates

TL;DR

This paper investigates how cooperative ring-exchange mechanisms can induce quantum melting of vortex lattices in rapidly rotating atomic Bose-Einstein condensates, providing insights into quantum phase transitions in such systems.

Contribution

It introduces a novel approach to analyze quantum melting in BEC vortex lattices using large-correlated ring exchanges inspired by fractional quantum Hall effect methods.

Findings

Identifies conditions for quantum melting instability in vortex lattices.

Proposes BEC as a platform to study quantum melting of Wigner solids.

Connects vortex lattice melting to fractional quantum Hall physics.

Abstract

Cooperative ring-exchange is suggested as a mechanism of quantum melting of vortex lattices in a rapidly-rotating quasi two dimensional atomic Bose-Einstein condensate (BEC). Using an approach pioneered by Kivelson et al. [Phys. Rev. Lett. {\bf 56}, 873 (1986)] for the fractional quantized Hall effect, we calculate the condition for quantum melting instability by considering large-correlated ring exchanges in a two-dimensional Wigner crystal of vortices in a strong `pseudomagnetic field' generated by the background superfluid Bose particles. BEC may be profitably used to address issues of quantum melting of a pristine Wigner solid devoid of complications of real solids.