Symmetry-conserving vortex clusters in small rotating clouds of ultracold bosons

TL;DR

This paper investigates symmetry-preserving vortex clusters in small rotating bosonic clouds, showing they have lower energy and better describe vortex formation than traditional mean-field states, highlighting different physics in small systems.

Contribution

It introduces and analyzes rotating vortex clusters that conserve angular momentum, providing a novel description surpassing mean-field approaches for small bosonic systems.

Findings

RVC states have lower energy than GP states.

GP states are wave packets of RVC states.

Small bosonic clouds exhibit different physics from larger condensates.

Abstract

The properties of a special class of correlated many-body wave functions, named rotating vortex clusters (RVCs), that preserve the total angular momentum of a small cloud of trapped rotating bosons are investigated. They have lower energy and provide a superior description for the formation of vortices compared to the mean-field Gross-Pitaevskii (GP) states that break the rotational symmetry. The GP vortex states are shown to be wave packets composed of such RVC states. Our results suggest that, for a small number of bosons, the physics is different from that of ideal Bose-Einstein condensates which characterize larger assemblies