Fr\"{o}hlich Condensate of Phonons in Optomechanical Systems

TL;DR

This paper explores how optomechanical systems, specifically a membrane array coupled to a cavity, can realize Fröhlich condensates of phonons, with potential applications in phonon lasers and energy transfer.

Contribution

It introduces a model for Fröhlich phonon condensation in optomechanical arrays and predicts conditions for high phonon occupancy and suppressed decoherence.

Findings

High phonon occupancy achievable in specific modes

Decoherence suppressed by large membrane arrays

Potential for narrow-linewidth phonon lasers

Abstract

We propose that the optomechanical systems can be potential platforms to implement the Fr\"{o}hlich condensate of phonons. We consider a one-dimensional array of membranes coupled to the cavity field via a quadratic interaction, and the cavity is pumped by an external laser. Analytical and numerical results predict that the high phonon occupancy of the lowest or highest mechanical mode is achievable depending on the detuning of the driving laser, the optomechnical strength, and the temperature. The decoherence of the Fr\"{o}hlich condensate can be largely suppressed by the large number of membranes. Our results shed light on narrow-linewidth phonon laser, energy conversion/transfer, and efficient multimode cooling.