Quantum repeaters and quantum key distribution: the impact of entanglement distillation on the secret key rate

TL;DR

This paper analyzes how entanglement distillation protocols and strategies affect the secret key rate in quantum repeaters for quantum key distribution, considering factors like classical communication time and detector efficiency.

Contribution

It provides an analytical expression for entangled pair creation and optimizes secret key rate considering various practical parameters.

Findings

Optimal distillation strategies improve key rate

Classical communication time significantly impacts performance

Detector efficiency influences the achievable secret key rate

Abstract

We investigate quantum repeaters in the context of quantum key distribution. We optimize the secret key rate per memory per second with respect to different distillation protocols and distillation strategies. For this purpose, we also derive an analytical expression for the average number of entangled pairs created by the quantum repeater, including classical communication times for entanglement swapping and entanglement distillation. We investigate the impact of this classical communication time on the secret key rate. We finally study the effect of the detector efficiency on the secret key rate.