Single-Photon Transistor Using a F\"orster Resonance

TL;DR

This paper demonstrates an all-optical single-photon transistor using Rydberg blockade enhanced by a F"orster resonance, achieving a gain of 20 with high fidelity, enabling complex quantum optical computations.

Contribution

It introduces a novel single-photon transistor leveraging F"orster resonance to enhance Rydberg blockade, achieving high gain and fidelity at the quantum limit.

Findings

Achieved a gain of 20 with a single gate photon.

Fidelity of single-shot detection above 0.86.

Demonstrated quantum-limited operation of the transistor.

Abstract

An all-optical transistor is a device in which a gate light pulse switches the transmission of a target light pulse with a gain above unity. The gain quantifies the change of the transmitted target photon number per incoming gate photon. We study the quantum limit of one incoming gate photon and observe a gain of 20. The gate pulse is stored as a Rydberg excitation in an ultracold gas. The transmission of the subsequent target pulse is suppressed by Rydberg blockade which is enhanced by a F\"orster resonance. The detected target photons reveal in a single shot with a fidelity above 0.86 whether a Rydberg excitation was created during the gate pulse. The gain offers the possibility to distribute the transistor output to the inputs of many transistors, thus making complex computational tasks possible.