Classical versus quantum intensity-field correlations of scattered light from extended cold atomic clouds

TL;DR

This paper compares classical and quantum intensity-field correlations in light scattered by cold atoms, highlighting differences based on atomic states and providing analytic and numerical insights into these correlations.

Contribution

It introduces analytic expressions for correlation functions in different atomic states and compares them with simulations, advancing understanding of light scattering in cold atomic systems.

Findings

Analytic formulas for correlation functions in entangled and coherent states.

Good agreement between numerical simulations and analytic solutions.

Fundamental differences in correlations depending on atomic state.

Abstract

We calculate the intensity-field correlations in the light scattered by N cold atoms driven by a quasi-resonant laser field. Fundamental differences occur if the atomic state is an entangled single-excitation state or a coherent factorized state. We provide analytic expressions for the two-time field and intensity correlation functions for the timed Dicke state and the quasi-Bloch state. The comparison with multi-atom simulations shows good agreement between numerical and analytic solutions.