Experimental measurement-device-independent quantum key distribution with the double-scanning method

TL;DR

This paper experimentally demonstrates a double-scanning method in measurement-device-independent quantum key distribution, significantly increasing key rates and enabling secure transmission over 150 km, advancing practical quantum communication.

Contribution

First experimental implementation of Jiang et al.'s double-scanning method in MDI-QKD, improving key rate and transmission distance.

Findings

Achieved 150 km secure transmission distance.

Used 10^10 pulses for the experiment.

Demonstrated practical feasibility of the method.

Abstract

The measurement-device-independent quantum key distribution (MDI-QKD) can be immune to all detector side-channel attacks. Moreover, it can be easily implemented combining with the matured decoy-state methods under current technology. It thus seems a very promising candidate in practical implementation of quantum communications. However, it suffers from severe finite-data-size effect in most existing MDI-QKD protocols, resulting in relatively low key rates. Recently, Jiang et al. [Phys. Rev. A 103, 012402 (2021)] proposed a double-scanning method to drastically increase the key rate of MDI-QKD. Based on Jiang et al.'s theoretical work, here we for the first time implement the double-scanning method into MDI-QKD and carry out corresponding experimental demonstration. With a moderate number of pulses of 10^10, we can achieve 150 km secure transmission distance which is impossible with all former methods. Therefore, our present work paves the way towards practical implementation of MDI-QKD.