Optimal pair generation rate for Entanglement-based QKD

TL;DR

This paper develops and experimentally validates a predictive model to optimize the two-fold coincidence probability in entanglement-based QKD, balancing entanglement visibility and coincidence events to maximize secure key rate.

Contribution

It introduces a novel predictive model for optimal coincidence probability in entanglement-based QKD, validated through experiments and simulations for satellite and fiber systems.

Findings

The model accurately predicts optimal coincidence probability under various system parameters.

Experimental validation confirms the model's effectiveness in real-world conditions.

Simulations demonstrate improved secure key rate optimization in satellite and fiber QKD setups.

Abstract

In entanglement-based quantum key distribution (QKD), the generation and detection of multi-photon modes leads to a trade-off between entanglement visibility and two-fold coincidence events when maximizing the secure key rate (SKR). We produce a predictive model for the optimal two-fold coincidence probability per coincidence window given the channel efficiency and detector dark count rate of a given system. This model is experimentally validated and used in simulations for QKD with satellites as well as optical fibers.