Time-averaged adiabatic ring potential for ultracold atoms

TL;DR

This paper demonstrates a versatile, long-lived ring trap for ultracold atoms created by a time-averaged adiabatic potential, enabling studies of superfluidity and matter-wave interferometry.

Contribution

The authors experimentally realize a ring-shaped trap for ultracold atoms using a novel time-averaged adiabatic potential method, with variable radius and efficient loading.

Findings

Bose-Einstein condensates in the ring have lifetimes exceeding 11 seconds.

The ring radius can be continuously varied from 50μm to 261μm.

The setup enables studies of superfluid properties and matter-wave interferometry.

Abstract

We report the experimental realisation of a versatile ring trap for ultracold atoms. The ring geometry is created by the time-averaged adiabatic potential resulting from the application of an oscillating magnetic bias field to a rf dressed quadrupole trap. Lifetimes for a Bose-Einstein condensate in the ring exceed 11s and the ring radius was continuously varied from 50$\mu$m to 261$\mu$m. An efficient method of loading the ring from a conventional TOP trap is presented together with a rotation scheme which introduces angular momentum into the system. The ring presents an opportunity to study the superfluid properties of a condensate in a multiply connected geometry and also has applications for matter-wave interferometry.