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 π-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.
@article{arxiv.1605.04456,
title = {Single-photon absorber based on strongly interacting Rydberg atoms},
author = {Christoph Tresp and Christian Zimmer and Ivan Mirgorodskiy and Hannes Gorniaczyk and Asaf Paris-Mandoki and Sebastian Hofferberth},
journal= {arXiv preprint arXiv:1605.04456},
year = {2016}
}