Classical and Quantum Theory of Photothermal Cavity Cooling of a Mechanical Oscillator

TL;DR

This paper demonstrates through classical and quantum analysis that photothermal cavity cooling can achieve the quantum ground state of a mechanical oscillator, especially with small cavity detuning allowing many photons.

Contribution

It provides the first comprehensive classical and quantum analysis confirming the feasibility of reaching the ground state via photothermal cavity cooling.

Findings

Ground state can be reached with photothermal cooling

Small cavity detuning enables large photon entry

Classical and quantum results are consistent

Abstract

Photothermal effects allow very efficient optomechanical coupling between mechanical degrees of freedom and photons. In the context of cavity cooling of a mechanical oscillator, the question of if the quantum ground state of the oscillator can be reached using photothermal back-action has been debated and remains an open question. Here we address this problem by complementary classical and quantum calculations. Both lead us to conclude that: first, the ground-state can indeed be reached using photothermal cavity cooling, second, it can be reached in a regime where the cavity detuning is small allowing a large amount of photons to enter the cavity.