Quantum-coherent coupling of a mechanical oscillator to an optical cavity mode

TL;DR

This paper demonstrates quantum-coherent coupling between a mechanical oscillator and an optical cavity mode, achieving ground-state cooling and observing energy exchange at the quantum level, advancing quantum interface development.

Contribution

It reports the first realization of quantum-coherent coupling between mechanical and optical modes in a micro-optomechanical system, with ground-state cooling and quantum energy exchange observation.

Findings

Mechanical oscillator cooled to n=1.7 quanta

Energy exchange observed at less than one quantum

Achieved quantum-coherent coupling in a micro-optomechanical system

Abstract

Quantum control of engineered mechanical oscillators can be achieved by coupling the oscillator to an auxiliary degree of freedom, provided that the coherent rate of energy exchange exceeds the decoherence rate of each of the two sub-systems. We achieve such quantum-coherent coupling between the mechanical and optical modes of a micro-optomechanical system. Simultaneously, the mechanical oscillator is cooled to an average occupancy of n = 1.7 \pm 0.1 motional quanta. Pulsed optical excitation reveals the exchange of energy between the optical light field and the micromechanical oscillator in the time domain at the level of less than one quantum on average. These results provide a route towards the realization of efficient quantum interfaces between mechanical oscillators and optical fields.