The radiation pressure of light can act to damp and cool the vibrational motion of a mechanical resonator. In understanding the quantum limits of this cooling, one must consider the effect of shot noise fluctuations on the final thermal occupation. In optomechanical sideband cooling in a cavity, the finite Stokes Raman scattering defined by the cavity linewidth combined with shot noise fluctuations dictates a quantum backaction limit, analogous to the Doppler limit of atomic laser cooling. In our work we sideband cool to the quantum backaction limit by using a micromechanical membrane precooled in a dilution refrigerator. Monitoring the optical sidebands allows us to directly observe the mechanical object come to thermal equilibrium with the optical bath.
@article{arxiv.1510.03911,
title = {Laser cooling of a micromechanical membrane to the quantum backaction limit},
author = {R. W. Peterson and T. P. Purdy and N. S. Kampel and R. W. Andrews and P. -L. Yu and K. W. Lehnert and C. A. Regal},
journal= {arXiv preprint arXiv:1510.03911},
year = {2016}
}