Controlling Rydberg atom-polariton interactions: from exceptional points to fast readout

TL;DR

This paper investigates the interactions between Rydberg polaritons and single Rydberg atoms, revealing different quantum regimes and exceptional points, with potential applications in fast atom detection and nonlinear photonic networks.

Contribution

It experimentally identifies three quantum interaction regimes and demonstrates the transition through an exceptional point in Rydberg atom-polariton systems.

Findings

Identified polariton blockade, coherent exchange, and probabilistic hopping regimes.

Discovered a transition through an exceptional point between blockade and exchange.

Demonstrated potential for fast, non-destructive Rydberg atom detection.

Abstract

Rydberg atoms represent a platform underpinning many recent developments in quantum computation, simulation, sensing, and metrology. They further facilitate optical nonlinearity at the single-photon level when coupled to photons propagating in atomic clouds, which form collective atomic excitations called Rydberg polaritons, strongly interacting with each other. Here, we experimentally explore interactions between a Rydberg polariton in an atomic ensemble and a single, adjacent, Rydberg atom. We discover three different regimes of quantum dynamics corresponding to polariton blockade, coherent exchange, and probabilistic hopping, which are defined by their distinct transmission characteristics, with a transition through an exceptional point occurring between blockade and coherent exchange. We investigate the applications of such interactions for fast, non-destructive detection of Rydberg atoms and present proof-of-principle demonstrations for their potential application in nonlinear photonic networks.