Analyzing the effectiveness of the quantum repeater

TL;DR

This paper evaluates the effectiveness of quantum repeaters in extending quantum key distribution (QKD) over long distances, considering repeater noise and security implications.

Contribution

It provides a comprehensive analysis of quantum repeater effectiveness including noise effects and confirms the security of QKD with repeaters.

Findings

Quantum repeaters can extend QKD distance despite noise.

QKD remains secure when using quantum repeaters.

Analysis includes effects of repeater noise on performance.

Abstract

The communication distance of QKD is limited by exponential attenuation of photons propagating through optical fibers. However, it has been shown that introducing a quantum repeater can improve the order of the attenuation and is useful for extending the communication distance of QKD when the repeater noise is ignored. In this paper, we analyze the effectiveness of the quantum repeater when taking the repeater noise into consideration. We analyze the effectiveness also from the viewpoint of the security and show that QKD is secure even if a quantum repeater is used.