Quantum and Nonlinear Optics in Strongly Interacting Atomic Ensembles

TL;DR

This paper reviews the rapidly advancing field of coupling light with strongly interacting atomic ensembles, especially Rydberg states, to achieve unprecedented photon nonlinearities and explore quantum nonlocal effects.

Contribution

It provides a comprehensive overview of theoretical concepts, experimental breakthroughs, and future applications in quantum and nonlinear optics with strongly interacting atoms.

Findings

Demonstration of strong photon-photon interactions via Rydberg states

Observation of quantum nonlocal nonlinearities in atomic ensembles

Potential for developing quantum information processing technologies

Abstract

Coupling light to ensembles of strongly interacting particles has emerged as a promising route toward achieving few photon nonlinearities. One specific way to implement this kind of nonlinearity is to interface light with highly excited atomic Rydberg states by means of electromagnetically induced transparency, an approach which allows freely propagating photons to acquire synthetic interactions of hitherto unprecedented strength. Here, we present an overview of this rapidly developing field, from classical effects to quantum manifestations of the nonlocal nonlinearities emerging in such systems. With an emphasis on underlying theoretical concepts, we describe the many experimental breakthroughs so far demonstrated and discuss potential applications looming on the horizon.