Giant enhancement of tunable optomechanical coupling via ultrarefractive medium

TL;DR

This paper proposes a method to significantly enhance optomechanical coupling in membrane systems by inducing ultrarefractive media through doping and external driving, enabling strong quantum interactions at various temperatures.

Contribution

It introduces a tunable ultrarefractive medium in optomechanical systems to achieve ultra-strong coupling and high quantum cooperativity, advancing control over quantum optomechanical interactions.

Findings

Achieves ultra-strong single-photon optomechanical coupling.

Demonstrates tunability of coupling strength and force nature.

Predicts high quantum cooperativity with doped membranes.

Abstract

Exploring the fundamental quantum behaviour of optomechanical resonators is of great interest recently but requires the realization of the strong coupling regime. We study the optical photon-phonon coupling of the so-called membrane in the middle (MITM) optomechanical system. Using coupled-mode theory we find that the optomechanical coupling is proportional to the electric susceptibility of the membrane. By considering the doping atoms or spins into the membrane and driving these appropriately we induce a tunable ultra-large refractive index without absorption which enhances the optomechanical coupling. Using this we predict an ultra-strong single-optical photon strong coupling with large quantum cooperativity for Er3+ dopants at low temperature, while Cr3+ in a Ruby membrane may display ultra-large quantum cooperativity at room temperature. Our scheme also can tune the strength of the coupling over a wide range and can also control whether the optomechanical force is attractive or repulsive. Our work opens a door for fundamental physics and applications relying on the realization of the strong coupling regime in quantum optomechanical systems.