Cavity Opto-Mechanics with a Bose-Einstein Condensate

TL;DR

This paper demonstrates a novel cavity opto-mechanical system where a Bose-Einstein condensate's collective density excitation acts as a mechanical oscillator, enabling exploration of quantum regimes and non-local coupling.

Contribution

It introduces a new cavity opto-mechanical platform using a Bose-Einstein condensate as the mechanical element, approaching strong coupling with potential for quantum regime investigations.

Findings

Strong back-action dynamics observed with few photons

Quantitative agreement with cavity opto-mechanical model

Approaching the strong coupling regime

Abstract

Cavity opto-mechanics studies the coupling between a mechanical oscillator and a cavity field, with the aim to shed light on the border between classical and quantum physics. Here we report on a cavity opto-mechanical system in which a collective density excitation of a Bose-Einstein condensate is shown to serve as the mechanical oscillator coupled to the cavity field. We observe that a few photons inside the ultrahigh-finesse cavity trigger a strongly driven back-action dynamics, in quantitative agreement with a cavity opto-mechanical model. With this experiment we approach the strong coupling regime of cavity opto-mechanics, where a single excitation of the mechanical oscillator significantly influences the cavity field. The work opens up new directions to investigate mechanical oscillators in the quantum regime and quantum gases with non-local coupling.