Classical dynamics of the optomechanical modes of a Bose-Einstein condensate in a ring cavity

TL;DR

This paper explores the classical dynamics of a Bose-Einstein condensate in a ring cavity, revealing multistability and complex behaviors due to interactions with counterpropagating light modes.

Contribution

It introduces a detailed analysis of the optomechanical modes of a BEC in a ring cavity, highlighting new multistable phenomena and dynamic behaviors not seen in standing-wave cavity systems.

Findings

Presence of symmetric and antisymmetric density side modes excited by light

Rich multistable behavior including isolated solution branches

Dynamic responses to variations in laser frequency

Abstract

We consider a cavity optomechanical system consisting of a Bose-Einstein condensate (BEC) interacting with two counterpropagating traveling-wave modes in an optical ring cavity. In contrast to the more familiar case where the condensate is driven by the standing-wave field of a high-$Q$ Fabry-P{\'e}rot cavity we find that both symmetric and antisymmetric collective density side modes of the BEC are mechanically excited by the light field. In the semiclassical, mean-field limit where the light field and the zero-momentum mode of the condensate are treated classically the system is found to exhibit a rich multistable behavior, including the appearance of isolated branches of solutions (isolas). We also present examples of the dynamics of the system as input parameters such as the frequency of the driving lasers are varied.