Dynamical Coupling between a Bose-Einstein Condensate and a Cavity Optical Lattice

TL;DR

This paper investigates the nonlinear dynamical interaction between a Bose-Einstein condensate and an optical cavity, revealing bistability and back-action effects at the quantum level.

Contribution

It demonstrates the strong, nonlinear coupling between atomic motion and light in a cavity-BEC system, including bistability at the single-photon level.

Findings

Observation of bistability below single photon level

Detection of back-action dynamics tuning the system out of resonance

Nonlinear dependence of optical lattice depth on atomic density

Abstract

A Bose-Einstein condensate is dispersively coupled to a single mode of an ultra-high finesse optical cavity. The system is governed by strong interactions between the atomic motion and the light field even at the level of single quanta. While coherently pumping the cavity mode the condensate is subject to the cavity optical lattice potential whose depth depends nonlinearly on the atomic density distribution. We observe bistability already below the single photon level and strong back-action dynamics which tunes the system periodically out of resonance.