Measurement-device-independent quantum key distribution with all-photonic adaptive Bell measurement

TL;DR

This paper introduces an all-photonic adaptive Bell measurement in measurement-device-independent QKD, achieving a square root improvement in key rate and enhancing entanglement generation efficiency, thus advancing secure quantum communication.

Contribution

It demonstrates that all-photonic adaptive Bell measurement can be integrated into mdiQKD, providing significant improvements in key rate and entanglement generation over previous methods.

Findings

Square root improvement in key rate with adaptive Bell measurement

Enhanced entanglement generation efficiency in quantum repeaters

Feasibility of all-photonic adaptive Bell measurement in mdiQKD

Abstract

The time-reversed version of entanglement-based quantum key distribution (QKD), called measurement-device-independent QKD (mdiQKD), was originally introduced to close arbitrary security loopholes of measurement devices. Here we show that the mdiQKD has another advantage which should be distinguished from the entanglement-based QKD. In particular, an all-photonic adaptive Bell measurement, based on the concept of quantum repeaters, can be installed solely in the mdiQKD, which leads to a square root improvement in the key rate. This Bell measurement also provides a similar improvement in the single-photon-based entanglement generation of quantum repeaters.