We measure the fundamental noise processes associated with a continuous linear position measurement of a micromechanical membrane incorporated in a microwave cavity optomechanical circuit. We observe the trade-off between the two fundamental sources of noises that enforce the standard quantum limit: the measurement imprecision and radiation-pressure backaction from photon shot noise. We demonstrate that the quantum backaction of the measurement can overwhelm the intrinsic thermal motion by 24 dB, entering a new regime for cavity optomechanical systems.
@article{arxiv.1508.05320,
title = {Overwhelming thermomechanical motion with microwave radiation pressure shot noise},
author = {J. D. Teufel and F. Lecocq and R. W. Simmonds},
journal= {arXiv preprint arXiv:1508.05320},
year = {2016}
}