A cavity-QED protocol for precise field sensing in the optical domain

TL;DR

This paper proposes a cavity-QED based method to generate non-classical light states for highly sensitive electric field measurements, surpassing classical limits, using current atomic systems.

Contribution

It introduces a novel application of optical cavity-QED to create atom-light cat states for quantum-enhanced sensing of electric fields, extending beyond traditional atomic spin state uses.

Findings

Achieves 10-20 dB sensitivity improvement over standard quantum limit.

Demonstrates feasibility with existing cavity-QED systems and alkaline-earth atoms.

Shows robustness of the protocol against photon loss.

Abstract

In the context of quantum metrology, optical cavity-QED platforms have primarily been focused on the generation of entangled atomic spin states useful for next-generation frequency and time standards. Here, we report a complementary application: The use of optical cavities to generate non-classical states of light for electric field sensing below the standard quantum limit. We show that cooperative atom-light interactions in the strong collective coupling regime can be used to engineer generalized atom-light cat states which enable quantum enhanced sensing of small displacements of the cavity field even in the presence of photon loss. We demonstrate that metrological gains of 10-20 dB below the standard quantum limit are within reach for current cavity-QED systems operating with long-lived alkaline-earth atoms.