Collective Spin-Light and Light-Mediated Spin-Spin Interactions in an Optical Cavity

TL;DR

This paper investigates how strong atom-light interactions in an optical cavity can generate entanglement between atoms and light, with implications for enhancing quantum sensors and atomic clocks.

Contribution

It provides a unified analytical framework for understanding atom-light and atom-atom entanglement in high-finesse cavities, including conditions to optimize quantum enhancement.

Findings

Analytical expressions for entanglement induced by cavity interactions

Conditions to maximize entanglement gain over standard quantum limit

Unified approach accounting for measurement and non-measurement scenarios

Abstract

The interaction between an atomic ensemble and a light mode in a high-finesse optical cavity can easily reach the strong-coupling regime, where quantum effects dominate. In this regime, the interaction can be used to generate both atom-light and atom-atom entanglement. We analyze the dominant effects on the collective atomic state and the light field, and derive a unified approach that can account for atomic entanglement induced both by measurements on the light field, and by ignoring the state of the light field altogether. We present analytical expressions for the entanglement induced by the interaction, and determine the conditions that maximize the entanglement-induced gain over the standard quantum limit in quantum sensors and atomic clocks.