Enhancement of Rydberg-mediated single-photon nonlinearities by electrically tuned F\"orster Resonances

TL;DR

This paper demonstrates that electrically tuning F"orster resonances significantly enhances Rydberg-mediated single-photon nonlinearities, enabling high-gain optical switching, improved detection fidelity, and precise spectroscopy, advancing photonic quantum gate development.

Contribution

It experimentally shows Stark-tuned F"orster resonances can greatly increase photon-photon interactions in Rydberg systems, with theoretical models confirming the mechanisms involved.

Findings

Single-photon transistor gain exceeds 100

Detection fidelity of single Rydberg atoms surpasses 0.8

Achieved a gain larger than 2 with gate photon read-out

Abstract

Mapping the strong interaction between Rydberg atoms onto single photons via electromagnetically induced transparency enables manipulation of light on the single photon level and novel few-photon devices such as all-optical switches and transistors operated by individual photons. Here, we demonstrate experimentally that Stark-tuned F\"orster resonances can substantially increase this effective interaction between individual photons. This technique boosts the gain of a single-photon transistor to over 100, enhances the non-destructive detection of single Rydberg atoms to a fidelity beyond 0.8, and enables high precision spectroscopy on Rydberg pair states. On top, we achieve a gain larger than 2 with gate photon read-out after the transistor operation. Theory models for Rydberg polariton propagation on F\"orster resonance and for the projection of the stored spin-wave yield excellent agreement to our data and successfully identify the main decoherence mechanism of the Rydberg transistor, paving the way towards photonic quantum gates.