Atom-based coherent quantum-noise cancellation in optomechanics

TL;DR

This paper proposes a hybrid optomechanical sensor utilizing atom-based coherent quantum noise cancellation to surpass the Standard Quantum Limit, enabling broad-band detection of weak forces with reduced dissipation constraints.

Contribution

It introduces a novel hybrid dual-cavity system combining atomic ensembles and mechanical resonators for enhanced quantum sensing.

Findings

Achieves quantum noise cancellation with relaxed dissipation constraints.

Enables broad-band detection of feeble forces.

Supports cooling of mechanical resonators via atomic ensembles.

Abstract

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.