Realization of an untrusted intermediate relay architecture using a quantum dot single-photon source

TL;DR

This paper demonstrates a scalable quantum relay network using a high-quality single-photon source with untrusted nodes, enabling secure quantum communication over 300 km with high repetition rates.

Contribution

It introduces a modular, scalable quantum relay architecture with untrusted nodes and high repetition rate, utilizing a measurement-device-independent protocol for secure long-distance communication.

Findings

Secure key establishment over 300 km fiber links

Repetition rate of 304.52 MHz achieved

Potential for enhanced quantum network deployment

Abstract

To fully exploit the potential of quantum technologies, quantum networks are needed to link different systems, significantly enhancing applications in computing, cryptography, and metrology. Central to these networks are quantum relays that can facilitate long-distance entanglement distribution and quantum communication. In this work, we present a modular and scalable quantum relay architecture using a high-quality single-photon source. The proposed network incorporates three untrusted intermediate nodes and is capable of a repetition rate of 304.52 MHz. We use a measurement-device-independent protocol to demonstrate secure key establishment over fibers covering up to 300 kilometers. This study highlights the potential of single-photon sources in quantum relays to enhance information transmission, expand network coverage, and improve deployment flexibility, with promising applications in future quantum networks.