Quantum key distribution (QKD) can provide fundamentally proven security for secure communication. Toward application, the secret key rate (SKR) is a key figure of merit for any QKD system. So far, the SKR has been limited to about a few megabit-per-second. Here we report a QKD system that is able to generate key at a record high SKR of 115.8 Mb/s over 10-km standard fibre, and to distribute key over up to 328 km of ultra-low-loss fibre. This attributes to a multi-pixel superconducting nanowire single-photon detector with ultrahigh counting rate, an integrated transmitter that can stably encode polarization states with low error, a fast post-processing algorithm for generating key in real time and the high system clock-rate operation. The results demonstrate the feasibility of practical high-rate QKD with photonic techniques, thus opening its possibility for widespread applications.
@article{arxiv.2307.02364,
title = {High-rate quantum key distribution exceeding 110 Mb/s},
author = {Wei Li and Likang Zhang and Hao Tan and Yichen Lu and Sheng-Kai Liao and Jia Huang and Hao Li and Zhen Wang and Hao-Kun Mao and Bingze Yan and Qiong Li and Yang Liu and Qiang Zhang and Cheng-Zhi Peng and Lixing You and Feihu Xu and Jian-Wei Pan},
journal= {arXiv preprint arXiv:2307.02364},
year = {2023}
}