Expansion of a quantum gas in a shell trap

TL;DR

This paper demonstrates the controlled expansion of a two-dimensional quantum gas on a curved shell surface, revealing how hidden dimensions and topology influence low-dimensional quantum systems.

Contribution

It introduces a novel gravity compensation mechanism to explore the full ellipsoid in a shell trap, and compares experimental results with theoretical models.

Findings

Spontaneous emergence of an annular shape in atomic distribution

Agreement between experimental data and Gross-Pitaevskii simulations

Topology change induced by hidden dimension effects

Abstract

We report the observation of the controlled expansion of a two-dimensional quantum gas confined onto a curved shell-shaped surface. We start from the ellipsoidal geometry of a dressed quadrupole trap and introduce a novel gravity compensation mechanism enabling to explore the full ellipsoid. The zero-point energy of the transverse confinement manifests itself by the spontaneous emergence of an annular shape in the atomic distribution. The experimental results are compared with the solution of the three-dimensional Gross-Pitaevskii equation and with a two-dimensional semi-analytical model. This work evidences how a hidden dimension can affect dramatically the embedded low-dimensional system by inducing a change of topology.