Higher key rate of measurement-device-independent quantum key distribution through joint data processing

TL;DR

This paper introduces a double-scanning method that significantly enhances the key rate of measurement-device-independent quantum key distribution by jointly estimating critical parameters, with potential improvements up to 280%.

Contribution

The paper presents a novel double-scanning technique for MDI-QKD that improves key rates and explores comprehensive parameter optimization for better performance.

Findings

Key rate improved by 35%-280% with the new method.

Joint parameter estimation outperforms separate estimations.

Optimizing all parameters yields an additional 10% key rate increase.

Abstract

We propose a method named as double-scanning method, to improve the key rate of measurement-device-independent quantum key distribution (MDI-QKD) drastically. In the method, two parameters are scanned simultaneously to tightly estimate the counts of single-photon pairs and the phase-flip error rate jointly. Numerical results show that the method in this work can improve the key rate by $35\%-280\%$ in a typical experimental set-up. Besides, we study the optimization of MDI-QKD protocol with all parameters including the source parameters and failure probability parameters, over symmetric channel or asymmetric channel. Compared with the optimized results with only the source parameters, the all-parameter-optimization method could improve the key rate by about $10\%$.