We analyze a quantum force sensor that uses coherent quantum noise
cancellation (CQNC) to beat the Standard Quantum Limit (SQL). This sensor,
which allows for the continuous, broad-band detection of feeble forces, is a
hybrid dual-cavity system comprised of a mesoscopic mechanical resonator
optically coupled to an ensemble of ultracold atoms. In contrast to the
stringent constraints on dissipation typically associated with purely optical
schemes of CQNC, the dissipation rate of the mechanical resonator only needs to
be matched to the decoherence rate of the atomic ensemble -- a condition that
is experimentally achievable even for the technologically relevant regime of
low frequency mechanical resonators with large quality factors. The modular
nature of the system further allows the atomic ensemble to aid in the cooling
of the mechanical resonator, thereby combining atom-mediated state preparation
with sensing deep in the quantum regime.Comment: 7 pages, 3 figures; updated reference
We study theoretically the dynamics of multiple mechanical oscillators coupled to a single cavity field mode via linear or quadratic optomechanical interactions. We focus specifically on the strong coupling regime where the cavity decays much faster than the mechanical modes, and the optomechanical coupling is comparable to or larger than the mechanical frequency, so that both the optical and mechanical systems operate in the deep quantum regime. Using the examples of one and two mechanical oscillators we show that the system can classically exhibit bistability and bifurcations, and we explore how these manifest themselves in interference, entanglement, and correlation in the quantum theory, while revealing the impact of decoherence of the mechanical system due to cavity fluctuations and coherent driving.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.