Expansion of a quantum gas in a shell trap
Yanliang Guo, Emmanuel Mercado Gutierrez, David Rey, Thomas Badr, A. Perrin, Laurent Longchambon, Vanderlei Salvador Bagnato, Hélène Perrin, Romain Dubessy
Abstract
Abstract We report the observation of the controlled expansion of a two-dimensional (2D) 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 2D semi-analytical model. This work evidences how a hidden dimension can affect dramatically the embedded low-dimensional system by inducing a change of topology.