Ground-state cooling of mechanical resonators by quantum reservoir engineering

TL;DR

This paper introduces a quantum reservoir engineering scheme to cool mechanical resonators to their ground state using incoherent thermal sources, enabling simultaneous cooling of multiple resonators through spectral filtering.

Contribution

The authors propose a novel incoherent cooling method that leverages spectral filtering and quantum reservoir engineering to achieve ground-state cooling of multiple mechanical resonators.

Findings

Simultaneous cooling of two or more mechanical resonators is achievable.

Spectral filtering is crucial for effective cooling in the proposed scheme.

The method can be extended to multiple resonators and simulated high-temperature baths.

Abstract

We propose a scheme to cool down a mechanical resonator to its quantum ground-state, which is interacting with a working fluid via an optomechanical-like coupling. As opposed to standard laser cooling schemes where coherence renders the motion of a resonator to its ground-state, we consider an incoherent thermal source to achieve the same aim. We show that simultaneous cooling of two degenerate or near-degenerate mechanical resonators is possible, which is otherwise a challenging goal to achieve. The generalization of this method to the simultaneous cooling of multiple resonators is straightforward. Spectral filtering of the coupling between the cooling agent and the baths is a key to realize cooling in our scheme. The underlying physical mechanism of cooling is explained by investigating a direct connection between the laser sideband cooling and cooling by heating in a standard optomechanical setting. Our advantageous scheme of cooling enabled by quantum reservoir engineering can be realized in various setups, employing parametric coupling of a cooling agent with the target systems. We also discuss using non-thermal baths to simulate ultra-high temperature thermal baths for cooling.