Theory of ground state cooling of a mechanical oscillator using dynamical back-action

TL;DR

This paper develops a quantum theory for cooling mechanical oscillators via radiation pressure dynamical back-action, showing that ground state cooling is achievable when the oscillator frequency exceeds the cavity linewidth, with occupancy measurable from the output spectrum.

Contribution

It introduces a quantum model for dynamical back-action cooling, demonstrating conditions for reaching near ground state and methods for occupancy measurement.

Findings

Final occupancy below unity is possible with high-frequency oscillators.

The final average occupancy can be directly inferred from the optical output spectrum.

Ground state cooling conditions depend on the ratio of mechanical frequency to cavity linewidth.

Abstract

A quantum theory of cooling of a mechanical oscillator by radiation pressure-induced dynamical back-action is developed, which is analogous to sideband cooling of trapped ions. We find that final occupancies well below unity can be attained when the mechanical oscillation frequency is larger than the cavity linewidth. It is shown that the final average occupancy can be retrieved directly from the optical output spectrum.