Shell-shaped atomic gases

Irene Greghi

Motivated by the expected realization of a shell shaped BEC in microgravity I studied the thermodynamics of bosonic quantum gases confined on the surface of a sphere both in the ideal and in the interacting case. In particular, once I found the values of the parameters of the external potential that are such to confine the gas to the surface of a sphere I computed the critical temperature as a function of the total number of atoms, the condensate and the thermal density as a function of the radius both in the ideal and interacting case and finally also the condensate and thermal fraction are computed.

Henning Moritz

Mansoor Sheik‐Bahae, Denis V. Seletskiy

Alexander Wolf, Patrick Boegel, Matthias Meister +3 more

Ultracold quantum gases confined in three-dimensional bubble traps are promising tools for exploring many-body effects on curved manifolds. As an alternative to the conventional technique of radio-frequency dressing, we propose to create such shell-shaped Bose-Einstein condensates in microgravity based on dual-species atomic mixtures, and we analyze their properties as well as the feasibility of realizing symmetrically filled shells. Beyond similarities with the radio-frequency dressing method, as in the collective excitation spectrum, our approach has several natural advantages like the robustness of the created quantum bubbles and the possibility of magnifying shell effects through an interaction-driven expansion.

Nir Davidson

Patrick Boegel, Alexander Wolf, Matthias Meister +1 more

Abstract Motivated by the recent experimental realization of ultracold quantum gases in shell topology, we propose a straightforward implementation of matter-wave lensing techniques for shell-shaped Bose–Einstein condensates. This approach allows to significantly extend the free evolution time of the condensate shell after release from the trap and enables the study of novel quantum many-body effects on curved geometries. With both analytical and numerical methods we derive optimal parameters for realistic schemes to conserve the shell shape of the condensate for times up to hundreds of milliseconds.