Dipolar dephasing of Rydberg D-state polaritons

TL;DR

This paper experimentally investigates how anisotropic Rydberg interactions cause dephasing in D-state Rydberg polaritons, revealing interaction-induced effects at low photon rates and modeling pairwise interactions.

Contribution

It introduces the first experimental observation of interaction-induced dephasing in D-state Rydberg polaritons and provides a theoretical model explaining the phenomenon.

Findings

Observation of dephasing at very low photon input rates

Interaction effects attributed to pairwise Rydberg polariton interactions

Development of a combined propagation and nonperturbative interaction model

Abstract

We experimentally study the effects of the anisotropic Rydberg-interaction on $D$-state Rydberg polaritons slowly propagating through a cold atomic sample. In addition to the few-photon nonlinearity known from similar experiments with Rydberg $S$-states, we observe the interaction-induced dephasing of Rydberg polaritons at very low photon input rates into the medium. We develop a model combining the propagation of the two-photon wavefunction through our system with nonperturbative calculations of the anisotropic Rydberg-interaction to show that the observed effect can be attributed to pairwise interaction of individual Rydberg polaritons.