Generating and Trapping Vortices in a Bose-Einstein Condensate

Project Level: Honours/Masters

The UQ Bose-Einstein condensation lab has highly developed methods for producing thin films of atomic superfluid and trapping and manipulating them using optical tweezers. The aim of this project is to investigate quantum vortices in the superfluid, which are like tiny whirlpools broadly similar to classical systems but possessing quantised angular momentum.

Building on recent successes in experimentally producing and measuring these vortices at UQ (https://arxiv.org/abs/2010.10049), this project aims to experimentally investigate the results of other UQ research that theoretically looked at the dynamics of pinning vortices in the BEC (https://arxiv.org/abs/2102.04712). Quantised vortices can be pinned (have their position fixed in place) by producing a density dip in the superfluid. This theory paper investigated the strength and dynamics of pinning, depending on the depth of the density dip.

This project will aim to investigate a proof of principle experiment, where the depth of a pinning potential will be modified and the relative velocity of the barrier required for depinning determined. The project will involve developing a control sequence for the optical trap for the BEC, based on existing software. The aim will then be to experimentally pin vortices and then determine the barrier velocity required for unpinning.