Single-Photon Switch based on Rydberg Blockade

TL;DR

This paper demonstrates a quantum all-optical single-photon switch using Rydberg blockade in ultracold atoms, enabling control of light transmission at the single-photon level for quantum technologies.

Contribution

It introduces a novel single-photon switch based on Rydberg blockade, integrating quantum storage and control in ultracold atomic gases.

Findings

Achieved a 0.05 extinction of target pulse transmission.

Successfully stored and retrieved a single photon as a Rydberg excitation.

Demonstrated potential for quantum communication and information processing.

Abstract

All-optical switching is a technique in which a gate light pulse changes the transmission of a target light pulse without the detour via electronic signal processing. We take this to the quantum regime, where the incoming gate light pulse contains only one photon on average. The gate pulse is stored as a Rydberg excitation in an ultracold atomic gas using electromagnetically induced transparency. Rydberg blockade suppresses the transmission of the subsequent target pulse. Finally, the stored gate photon can be retrieved. A retrieved photon heralds successful storage. The corresponding postselected subensemble shows an extinction of 0.05. The single-photon switch offers many interesting perspectives ranging from quantum communication to quantum information processing.