Ultracold atoms in a cavity mediated double-well system

TL;DR

This paper investigates the ground-state properties and dynamics of ultracold atoms in a cavity-mediated double-well system, revealing phenomena like self-organization, suppressed Josephson oscillations, and collapse-revival effects due to atom-field interactions.

Contribution

It introduces a novel cavity-mediated double-well system and analyzes both mean-field and many-body dynamics, highlighting new nonlinear phenomena and quantum effects.

Findings

Critical pumping induces atomic self-organization and increased intra-cavity field.

Josephson oscillations are suppressed in certain regimes, indicating self-trapping.

Collapse-revival phenomena occur in Josephson oscillations for small atom numbers.

Abstract

We study ground-state properties and dynamics of a dilute ultracold atomic gas in a double well potential. The Gaussian barrier separating the two wells derives from the interaction between the atoms and a quantized field of a driven Fabry-Perot cavity. Due to intrinsic atom-field nonlinearity, several novel phenomena arise being the focus of this work. For the ground state, there is a critical pumping amplitude in which the atoms self-organize and the intra cavity field amplitude drastically increases. In the dynamical analysis, we show that the Josephson oscillations depend strongly on the atomic density and may be greatly suppressed within certain regimes, reminiscent of self-trapping of Bose-Einstein condensates in double-well setups. This pseudo self-trapping effect is studied within a mean-field treatment valid for large atom numbers. For small numbers of atoms, we consider the analogous many-body problem and demonstrate a collapse-revival structure in the Josephson oscillations.