Integrated Server for Measurement-Device-Independent Quantum Key Distribution Network

TL;DR

This paper presents an integrated server for measurement-device-independent quantum key distribution, using integrated photonic circuits to enhance scalability, stability, and practicality of quantum communication networks.

Contribution

The authors develop and experimentally demonstrate an integrated photonic platform for MDI-QKD, enabling scalable and stable quantum key distribution networks.

Findings

High-visibility Bell state analysis achieved

Integrated photonic circuits demonstrated on a single chip

Potential for practical MDI-QKD network implementation

Abstract

Quantum key distribution (QKD), harnessing quantum physics and optoelectronics, may promise unconditionally secure information exchange in theory. Recently, theoretical and experimental advances in measurement-device-independent (MDI-) QKD have successfully closed the physical backdoor in detection terminals. However, the issues of scalability, stability, cost and loss prevent QKD systems from widespread application in practice. Here, we propose and experimentally demonstrate a solution to build a star-topology quantum access network with an integrated server. By using femtosecond laser direct writing technique, we construct integrated circuits for all the elements of Bell state analyzer together and are able to integrate several such analyzers on single photonic chip. The measured high-visibility Bell state analysis suggests integrated server a promising platform for the practical application of MDI-QKD network.