Quantum key distribution (QKD) provides an attractive solution for secure communication. However, channel disturbance severely limits its application when a QKD system is transfered from the laboratory to the field. Here, a high-speed Faraday-Sagnac-Michelson QKD system is proposed that can automatically compensate for the channel polarization disturbance, which largely avoids the intermittency limitations of environment mutation. Over a 50-km fiber channel with 30-Hz polarization scrambling, the practicality of this phase-coding QKD system was characterized with an interference fringe visibility of 99:35% over 24 hours, and a stable secure key rate of 306k bits/s over 7 days without active polarization alignment.
@article{arxiv.1805.09952,
title = {Practical gigahertz quantum key distribution robust against channel disturbance},
author = {Shuang Wang and Wei Chen and Zhen-Qiang Yin and De-Yong He and Cong Hui and Peng-Lei Hao and Guan-Jie Fan-Yuan and Chao Wang and Li-Jun Zhang and Jie Kuang and Shu-Feng Liu and Zheng Zhou and Yong-Gang Wang and Guang-Can Guo and Zheng-Fu Han},
journal= {arXiv preprint arXiv:1805.09952},
year = {2018}
}