The quantum measurement of any observable naturally leads to noise added by the act of measurement. Approaches to evade or reduce this noise can lead to substantial improvements in a wide variety of sensors, from laser interferometers to precision magnetometers and more. In this paper, we develop a measurement protocol based upon pioneering work by the gravitational wave community which allows for reduction of added noise from measurement by coupling an optical field to the momentum of a small mirror. As a specific implementation, we present a continuous measurement protocol using a double-ring optomechanical cavity. We demonstrate that with experimentally-relevant parameters, this protocol can lead to significant back-action noise evasion, yielding measurement noise below the standard quantum limit over many decades of frequency.
@article{arxiv.1910.11892,
title = {Back-action evading impulse measurement with mechanical quantum sensors},
author = {Sohitri Ghosh and Daniel Carney and Peter Shawhan and Jacob M. Taylor},
journal= {arXiv preprint arXiv:1910.11892},
year = {2020}
}
Comments
9+2 pages, 5 figures. v2: published version, includes minor changes and a new appendix on possible experimental imperfections (in particular, effects of mild detuning and asymmetry between the two cavities)