Chiral Quantum-Optical Elements for Waveguide-QED with Sub-wavelength Rydberg-Atom Arrays

TL;DR

This paper presents a method to create highly efficient, unidirectional light-matter interactions using Rydberg-atom arrays, enabling high-fidelity quantum photon operations without complex optical components.

Contribution

It introduces a novel approach to achieve near-perfect unidirectional coupling with Rydberg superatoms for quantum photonic applications.

Findings

High-fidelity (>99.9%) single-photon generation

Deterministic entangling two-photon operations

Versatile nonlinear optical element for quantum networks

Abstract

We describe an approach to achieve near-perfect unidirectional light-matter coupling to an effective quantum emitter that is formed by a subwavelength array of atoms in the Rydberg-blockade regime. The nonlinear reflection and transmission of such two-dimensional superatoms are exploited in different interferometric setups for the deterministic generation of tunable single photons and entangling two-photon operations with high fidelities, $\mathcal{F}\gtrsim0.999$. The described setup can function as a versatile nonlinear optical element in a free-space photonic quantum network with simple linear elements and without the need of additional mode confinement, optical resonators, or optical isolators.