Photon-photon interactions in Rydberg-atom arrays

TL;DR

This paper explores how weak light interacts with two-dimensional Rydberg-atom arrays, revealing conditions for a nonlinear quantum mirror that can generate correlated photon pairs and manipulate quantum light without significant losses.

Contribution

It introduces a novel analysis of multi-scale interactions in Rydberg-atom arrays leading to a nonlinear quantum mirror for quantum light manipulation.

Findings

Identification of conditions for a nonlinear quantum mirror

Demonstration of correlated photon-pair generation

Potential for lossless quantum light control

Abstract

We investigate the interaction of weak light fields with two-dimensional lattices of atoms, in which two-photon coupling establishes conditions of electromagnetically induced transparency and excites high lying atomic Rydberg states. This system features different interactions that act on disparate length scales, from zero-range defect scattering of atomic excitations and finite-range dipole exchange interactions to long-range Rydberg-state interactions that span the entire array. Analyzing their interplay, we identify conditions that yield a nonlinear quantum mirror which coherently splits incident fields into correlated photon-pairs in a single transverse mode, while transmitting single photons unaffected. Such strong photon-photon interactions in the absence of otherwise detrimental photon losses in Rydberg-EIT arrays opens up a promising approach for the generation and manipulation of quantum light, and the exploration of many-body phenomena with interacting photons.