Disorder Induced Vortex Lattice Melting in Bose-Einstein Condensate

TL;DR

This paper investigates how impurities and disorder affect vortex lattice stability in Bose-Einstein condensates, revealing lattice distortion, formation of giant holes with hidden vortices, and melting phenomena due to disorder.

Contribution

It demonstrates the effects of single and random impurities on vortex lattice distortion, giant hole formation, and lattice melting in Bose-Einstein condensates.

Findings

Single impurity causes vortex lattice distortion depending on impurity position and strength.

Cluster of impurities can create giant holes with hidden vortices.

Disorder leads to vortex lattice melting and loss of long-range order.

Abstract

We study the vortex lattice dynamics in presence of single impurity as well as random impurities or disorder. We show that in presence of a single impurity the vortex lattice gets distorted and the distortion depends on the position of the single impurity with respect to the positions of the vortices in the impurity free Abrikosov vortex lattice and also the strength of the impurity potential. We then show that a new type of giant hole with hidden vortices inside it can be created in the vortex lattice by a cluster of impurities. In presence of random impurity potential or disorder the vortex lattice melts. We show that the vortex lattice also melts in presence of pseudorandom potential generated by the superposition of two optical lattices. The absence of long-range order in the melted vortex lattice is demonstrated from the structure factor profile and the histogram of the distances between each pair of the vortices.