Topologically trapped vortex molecules in Bose-Einstein condensates

TL;DR

This paper demonstrates the formation of topologically trapped vortex molecules in Bose-Einstein condensates using optical pinning, revealing new stable vortex configurations and discussing their experimental realization.

Contribution

It introduces a method to create and analyze vortex-antivortex molecules and multiquantum vortices in BECs through optical pinning and symmetry control.

Findings

Vortex-antivortex molecules can be stabilized by optical pinning.

Multiquantum vortices emerge as low-energy states under certain conditions.

Conditions for spontaneous nucleation of these vortex structures are identified.

Abstract

In a numerical experiment based on Gross-Pitaevskii formalism, we demonstrate unique topological quantum coherence in optically trapped Bose-Einstein condensates (BECs). Exploring the fact that vortices in rotating BEC can be pinned by a geometric arrangement of laser beams, we show the parameter range in which vortex-antivortex molecules or multiquantum vortices are formed as a consequence of the optically imposed symmetry. Being low-energy states, we discuss the conditions for spontaneous nucleation of these unique molecules and their direct experimental observation, and provoke the potential use of the phase print of an antivortex or a multiquantum vortex when realized in unconventional circumstances.