Bosonic pair production and squeezing for optical phase measurements in long-lived dipoles coupled to a cavity

TL;DR

This paper proposes a method to simulate bosonic pair creation using long-lived dipoles in a cavity, enabling quantum-enhanced optical phase sensing with potential applications in atomic clocks.

Contribution

It introduces a novel simulation of bosonic pair creation with long-lived dipoles and demonstrates a robust quantum sensing protocol for optical phase measurements.

Findings

Exponential growth of entanglement via virtual photon exchange

Implementation with Sr atoms for optical phase sensing

Robustness to decoherence in cavity platforms

Abstract

We propose to simulate bosonic pair creation using large arrays of long-lived dipoles with multilevel internal structure coupled to an undriven optical cavity. Entanglement between the atoms, generated by the exchange of virtual photons through a common cavity mode, grows exponentially fast and is described by two-mode squeezing of effective bosonic quadratures. The mapping between an effective bosonic model and the natural spin description of the dipoles allows us to realize the analog of optical homodyne measurements via straightforward global rotations and population measurements of the electronic states, and we propose to exploit this for quantum-enhanced sensing of an optical phase (common and differential between two ensembles). We discuss a specific implementation based on Sr atoms and show that our sensing protocol is robust to sources of decoherence intrinsic to cavity platforms. Our proposal can open unique opportunities for next-generation optical atomic clocks.