Cavity cooling of a mechanical resonator in the presence of two-level-system defects

TL;DR

This paper develops a theoretical model to analyze how two-level-system defects influence cavity cooling of mechanical resonators, highlighting the importance of TLS resonance and damping in the cooling efficiency.

Contribution

The study introduces a novel theoretical framework for understanding cavity cooling in the presence of TLS defects, using adiabatic elimination to account for defect interactions.

Findings

Cooling efficiency is strongly affected by TLS resonance conditions.

TLS damping rate significantly influences the cooling process.

The model predicts conditions for optimal cavity cooling despite defects.

Abstract

Cavity cooling via quantum backaction force can extract thermal fluctuations from a mechanical resonator to reach the quantum ground state. Surface or bulk two-level-system (TLS) defects in a mechanical resonator can couple with the mechanical mode via deformation potential and affect the cooling process significantly. Here, we develop a theory to study the cavity cooling of a mechanical mode in the presence of a TLS defect using the adiabatic elimination technique. Our result shows that the cooling process depends strongly on the resonance and the damping rate of the TLS.