# A Strongly Interacting Polaritonic Quantum Dot

## TL;DR

This paper demonstrates a novel strongly interacting Rydberg polaritonic quantum dot, combining cavity QED with Rydberg excitations to enable quantum information processing and exploration of topological quantum matter.

## Contribution

It introduces the first cavity quantum electrodynamics study of Rydberg polaritons in a quantum dot, revealing strong interactions and coherent quantum dynamics.

## Key findings

- Observation of blockaded polariton transport
- Coherent quantum dynamics of a polaritonic super-atom
- Establishment of a platform for quantum information processing

## Abstract

Polaritons are an emerging platform for exploration of synthetic materials [1] and quantum information processing [2] that draw properties from two disparate particles: a photon and an atom. Cavity polaritons are particularly promising, as they are long-lived and their dispersion and mass are controllable through cavity geometry [3]. To date, studies of cavity polaritons have operated in the mean-field regime, using short-range interactions between their matter components [4]. Rydberg excitations have recently been demonstrated as a promising matter-component of polaritons [5], due to their strong interactions over distances large compared to an optical wavelength. In this work we explore, for the first time, the cavity quantum electrodynamics of Rydberg polaritons, combining the non-linearity of polaritonic quantum wires with the zero-dimensional strong coupling of an optical resonator. We assemble a quantum dot composed of $\sim 150$ strongly interacting, Rydberg-dressed $^{87}$Rb atoms in a cavity, and observe blockaded polariton transport as well as coherent quantum dynamics of a single polaritonic super-atom. This work establishes a new generation of photonic quantum information processors and quantum materials, along with a clear path to topological quantum matter [6].