High rate, long-distance quantum key distribution over 250km of ultra low loss fibres

TL;DR

This paper demonstrates a high-speed quantum key distribution system over 250 km of ultra low loss fibers, achieving secure key rates suitable for long-distance quantum communication.

Contribution

It introduces a fully automated QKD prototype operating at 625 MHz, utilizing ultra low loss fibers and superconducting detectors for extended distance secure communication.

Findings

6,000 secret bits per second over 100 km

15 bits per second over 250 km

High rate, long-distance QKD achieved

Abstract

We present a fully automated quantum key distribution prototype running at 625 MHz clock rate. Taking advantage of ultra low loss fibres and low-noise superconducting detectors, we can distribute 6,000 secret bits per second over 100 km and 15 bits per second over 250km.