Facilitation Induced Transparency and Single Photon Switch with Dual-Channel Rydberg Interactions

TL;DR

This paper explores facilitation induced transparency (FIT) in dual-channel Rydberg atom systems, enabling active control of optical transparency and single-photon switching through long-range interactions and quantum interference effects.

Contribution

It introduces a novel FIT mechanism based on Rydberg interactions and interference pathways, distinct from traditional electromagnetically induced transparency, with potential for quantum device applications.

Findings

FIT is caused by Rydberg interactions and quantum interference.

The FIT is robust and insensitive to parameter changes.

The system can be used to realize controllable single-photon switches.

Abstract

We investigate facilitation induced transparency (FIT) enabled by strong and long-range Rydberg atom interactions between two spatially separated optical channels. In this setting, the resonant two-photon excitation of Rydberg states in a target channel is conditioned by a single Rydberg excitation in a control channel. Through the contactless coupling enabled by the Rydberg interaction, the optical transparency of the target channel can be actively manipulated by steering the optical detuning in the control channel. By adopting a dressed-state picture, we identify two different interference pathways, in which one corresponds to Rydberg blockade and an emergent one results from facilitation. We show that the FIT is originated from the Rydberg interaction and the quantum interference effect between the two pathways, which is different from conventional electromagnetically induced transparency realized by single-body laser-atom coupling. We find that the FIT in such a dual-channel setting is rather robust, insensitive to changes of systemic parameters, and can be generalized to multi-channel settings. Moreover, we demonstrate that such a FIT permits to realize controllable single-photon switches, which also paves a route to detect Rydberg facilitation by using optical absorption spectra. Our study contributes to current efforts in probing correlated many-body dynamics and developing single-photon quantum devices based on Rydberg atom ensembles.