Pinning of vortices in a Bose-Einstein condensate by an optical lattice

TL;DR

This paper studies how weak optical lattices can pin vortices in a Bose-Einstein condensate, causing phase transitions and unique vortex arrangements not seen in traditional condensed matter systems.

Contribution

It introduces the phase diagram of vortex states in 2D optical lattices and explores the novel effects of 1D optical potentials on vortex configurations.

Findings

Weak optical potentials induce vortex pinning and phase transitions.

Transition from triangular Abrikosov lattice to pinned vortex phases.

Unique vortex arrangements in 1D optical lattices.

Abstract

We consider the ground state of vortices in a Bose-Einstein condensate. We show that turning on a weak optical periodic potential leads to a transition from the triangular Abrikosov vortex lattice to phases where the vortices are pinned by the optical potential. We discuss the phase diagram of the system for a two-dimensional optical periodic potential with one vortex per optical lattice cell. We also discuss the influence of a one-dimensional optical periodic potential on the vortex ground state. The latter situation has no analogue in other condensed-matter systems.