Single-photon absorber based on strongly interacting Rydberg atoms

TL;DR

This paper demonstrates a deterministic single-photon absorber using Rydberg blockade in an optically thick medium, advancing quantum optics tools for quantum information and metrology.

Contribution

It introduces a scalable, Rydberg-based single-photon absorber that enhances quantum optics capabilities for quantum information processing.

Findings

Achieved deterministic photon absorption via Rydberg blockade.

Demonstrated scalability to multiple cascaded absorbers.

Enabled high-fidelity number-resolved photon detection.

Abstract

Removing exactly one photon from an arbitrary input pulse is an elementary operation in quantum optics and enables applications in quantum information processing and quantum simulation. Here we demonstrate a deterministic single-photon absorber based on the saturation of an optically thick free-space medium by a single photon due to Rydberg blockade. Single-photon subtraction adds a new component to the Rydberg quantum optics toolbox, which already contains photonic logic building-blocks such as single-photon sources, switches, transistors, and conditional $\pi$-phase shifts. Our approach is scalable to multiple cascaded absorbers, essential for preparation of non-classical light states for quantum information and metrology applications, and, in combination with the single-photon transistor, high-fidelity number-resolved photon detection.