Cavity-Enhanced Long-Distance Coupling of an Atomic Ensemble to a Micromechanical Membrane

TL;DR

This paper presents a hybrid quantum system where a dielectric membrane inside an optical cavity is coupled to a distant atomic ensemble via sideband photons, enabling coherent dynamics and sympathetic cooling without the need for resolved sideband conditions.

Contribution

It introduces a novel cavity-enhanced coupling scheme between a membrane and atomic ensemble, allowing for ground state cooling under realistic conditions.

Findings

Coherent dynamics observed between membrane and atomic ensemble

Sympathetic cooling of the membrane achieved through atomic laser cooling

Ground state cooling feasible with realistic parameters

Abstract

We discuss a hybrid quantum system where a dielectric membrane situated inside an optical cavity is coupled to a distant atomic ensemble trapped in an optical lattice. The coupling is mediated by the exchange of sideband photons of the lattice laser, and is enhanced by the cavity finesse as well as the square root of the number of atoms. In addition to observing coherent dynamics between the two systems, one can also switch on a tailored dissipation by laser cooling the atoms, thereby allowing for sympathetic cooling of the membrane. The resulting cooling scheme does not require resolved sideband conditions for the cavity, which relaxes a constraint present in standard optomechanical cavity cooling. We present a quantum mechanical treatment of this modular open system which takes into account the dominant imperfections, and identify optimal operation points for both coherent dynamics and sympathetic cooling. In particular, we find that ground state cooling of a cryogenically pre-cooled membrane is possible for realistic parameters.