Annular quantum gases in a bubble-shaped trap : from equilibrium to strong rotations

Guo, Yanliang

Published Jan 13, 2021• 0 citations

Abstract

Degenerate quantum gases offer an ideal platform to study superfluidity. An annular su- perfluid has many subtle properties due to its topological geometry. In this manuscript, we present three ring-shaped superfluids, obtained with different formation mechanisms. The starting point of the experiments is a superfluid confined at the bottom of a bubble- shaped trap, generated by dressing atoms in a quadrupole trap with radio-frequency (rf) photons. Taking advantage of the smoothness of such an adiabatic trap allows us to realize these three annular superfluids.The first one is a levitating ring, formed on the surface of the bubble trap by compensating gravity. We study the structure taken by the atomic cloud related to fine effect of the rf polarization and the strong rf coupling. The second one is a ring trap, formed at the equator of the bubble with an additional blue detuned double light sheet. We set the annular gas into rotation by two methods, resulting in a persistent superfluid current and a quantized circulation. The last one is a fast-rotating dynamical ring, which forms under the effect of the centrifugal force. It is a long-lived supersonic superfluid whose linear velocity can reach Mach18. We also evidence a collective mode of such a rapid rotating superfluid. The experimental realization of the dynamical ring is an important step towards the giant vortex regime

DOI: 10.70675/0c0524a7zabfbz48c3zab1bz17ae35183162

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