Dynamically controlled superradiant laser for hybrid sensing of collective atomic coherence

TL;DR

This paper demonstrates a dynamically controlled superradiant laser that maps atomic coherence onto light phase for enhanced sensing, approaching quantum-limited precision, and proposes a hybrid optical clock combining continuous and discrete measurements.

Contribution

It introduces a method for non-demolition mapping of atomic phase onto cavity light, enabling near-quantum-limited precision in atomic phase sensing.

Findings

The measurement precision can approach the standard quantum limit.

The method enables conditional Ramsey spectroscopy with enhanced sensitivity.

A hybrid optical lattice clock design is proposed.

Abstract

We implement dynamic control of a superradiant, cold atom $^{87}$Rb Raman laser to realize the equivalent of conditional Ramsey spectroscopy for sensing atomic phase shifts. Our method uses the non-demolition mapping of the collective quantum phase of an ensemble of two-level atoms onto the phase of a detected cavity light field. We show that the fundamental precision of the non-demolition measurement can theoretically approach the standard quantum limit on phase estimation for a coherent spin state, the traditional benchmark for Ramsey spectroscopy. Finally, we propose a hybrid optical lattice clock based on this method that combines continuous and discrete measurements to realize both high precision and accuracy.