近日，中国科学技术大学潘建伟和徐飞虎研究小组与上海微系统与信息技术研究所的尤立星研究员以及济南量子技术研究所的刘洋研究员等人合作，成功实现了超过110 Mb s-1的高速率量子密钥分发。相关研究成果已于2023年3月13日在国际学术期刊《自然—光子学》上发表。
该研究报道了一个量子密钥分发(QKD)系统，其能够在10公里标准光纤上以创纪录的 115.8 Mb/s 的密钥率生成密钥，并在328公里超低损耗光纤上分发密钥。这一成就得益于多像素超导纳米线单光子探测器的超高计数速率、能够以低误差稳定编码极化状态的集成发射器、实时生成密钥的快速后处理算法以及高系统时钟速率运行。这些结果展示了用光子技术实现高速QKD的可行性，从而为其广泛的应用开启了可能性。
研究人员表示，量子密钥分发(QKD)可以提供从根本上经过验证的安全通信。在应用方面，密钥率(SKR)是任何QKD系统的关键指标。到目前为止，SKR的速度被限制在每秒几兆位。
附：英文原文
Title: High-rate quantum key distribution exceeding 110 Mb s–1
Author: Li, Wei, Zhang, Likang, Tan, Hao, Lu, Yichen, Liao, Sheng-Kai, Huang, Jia, Li, Hao, Wang, Zhen, Mao, Hao-Kun, Yan, Bingze, Li, Qiong, Liu, Yang, Zhang, Qiang, Peng, Cheng-Zhi, You, Lixing, Xu, Feihu, Pan, Jian-Wei
Issue&Volume: 2023-03-13
Abstract: Quantum key distribution (QKD) can provide fundamentally proven secure communication. Towards application, the secret key rate (SKR) is a key figure of merit for any QKD system. The SKR has so far been limited to about a few megabits per second. Here we report a QKD system that is able to generate keys at a record high SKR of 115.8Mbs–1 over a 10km standard optical fibre, and distribute keys over up to 328km of ultralow-loss fibre. Such abilities are attributed to a multipixel superconducting nanowire single-photon detector with an ultrahigh counting rate, an integrated transmitter that can stably encode polarization states with low error, a fast post-processing algorithm for generating keys 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.
DOI: 10.1038/s41566-023-01166-4
