Cavity optomechanical detection of persistent currents and solitons in a bosonic ring condensate

TL;DR

This paper introduces a numerical simulation method for cavity optomechanical detection of persistent currents and solitons in a ring-shaped Bose-Einstein condensate, enabling real-time, minimally destructive measurement of condensate rotation.

Contribution

It presents a novel optomechanical detection technique for atomic condensates that measures rotation and soliton motion in situ, extending previous models and including effects of damping and noise.

Findings

Optical transmission spectra reveal signatures of condensate rotation.

Sensitivity depends on the system response frequency.

Measurement backaction influences atomic density profiles.

Abstract

We present numerical simulations of the cavity optomechanical detection of persistent currents and bright solitons in an atomic Bose-Einstein condensate confined in a ring trap. This work describes a novel technique that measures condensate rotation in situ, in real-time, and with minimal destruction, in contrast to currently used methods, all of which destroy the condensate completely. For weakly repulsive inter-atomic interactions, the analysis of persistent currents extends our previous few-mode treatment of the condensate [P. Kumar et al. Phys. Rev. Lett. 127, 113601 (2021)] to a stochastic Gross-Pitaevskii simulation. For weakly attractive atomic interactions, we present the first analysis of optomechanical detection of matter-wave soliton motion. We provide optical cavity transmission spectra containing signatures of the condensate rotation, sensitivity as a function of the system response frequency, and atomic density profiles quantifying the effect of the measurement backaction on the condensate. We treat the atoms at a mean-field level and the optical field classically, account for damping and noise in both degrees of freedom, and investigate the linear as well as nonlinear response of the configuration. Our results are consequential for the characterization of rotating matter waves in studies of atomtronics, superfluid hydrodynamics, and matter-wave soliton interferometry.