Free expansion of Bose-Einstein condensates with a multicharged vortex

TL;DR

This paper investigates how Bose-Einstein condensates with multicharged vortices expand freely, using variational and numerical methods to identify vortex properties from the expanded cloud's features.

Contribution

It introduces a combined variational and numerical approach to analyze free expansion of BECs with multicharged vortices, enabling vortex detection from expansion data.

Findings

Vortex multiplicity can be inferred from expansion properties.

Vortex core size evolution during expansion was characterized.

Asymptotic velocity depends on initial trap configuration.

Abstract

In this work, we analyze the free expansion of Bose-Einstein condensates containing multicharged vortices. The atomic cloud is initially confined in a three-dimensional asymmetric harmonic trap. We apply both approximate variational solutions and numerical simulations of the Gross-Pitaevskii equation. The data obtained provide a way to establish the presence as well as the multiplicity of vortices based only on the properties of the expanded cloud which can be obtained via time-of-flight measurements. In addition, several features such as the evolution of the vortex core size and the asymptotic velocity during free expansion were studied considering the atomic cloud as being released from different harmonic trap configurations.