Correlated photon emission from multi--atom Rydberg dark states

TL;DR

This paper demonstrates that dipole-dipole interactions among Rydberg atoms in a ladder scheme cause correlated photon emission, revealing new many-body quantum optical phenomena at large interatomic distances.

Contribution

It introduces a novel mechanism where Rydberg interactions prevent single-particle dark states, enabling correlated photon emission over large distances.

Findings

Correlated photon pairs are emitted with specific angular distributions.

Dipole-dipole interactions inhibit formation of single-particle dark states.

Photon correlations persist over distances larger than the emission wavelength.

Abstract

We consider three level atoms driven by two resonant light fields in a ladder scheme where the upper level is a highly excited Rydberg state. We show that the dipole--dipole interactions between Rydberg excited atoms prevents the formation of single particle dark states and leads to strongly correlated photon emission from atoms separated by distances large compared to the emission wavelength. For two atoms, correlated photon pairs are emitted with an angular distribution given by a coherent sum of the independent dipolar fields.