Abstract
The twin-field quantum key distribution (TF-QKD) protocol has been studied widely to overcome the linear bound, and several variations of the TF-QKD protocol have been proposed to improve security and practicality. One variation called the phase-matching QKD (PM-QKD) protocol develops an optical-mode-based security; simultaneously, it has a quadratic improvement of key rate without either basis choice or phase locking. So far, the main research work of the PM-QKD protocol has focused on symmetric channels. However, it is quite common that the two channels have asymmetric transmittances in real life. In this paper, we discuss the effects of asymmetric channels on the PM-QKD protocol; to reach a much better performance and achieve a higher key rate, the intensity must be optimized to compensate for channel asymmetry. We also study the practical issues of finite-key effects and intensity fluctuations, which have significant effects on the key rate of PM-QKD.
© 2021 Optical Society of America
Full Article | PDF ArticleMore Like This
Yang Wang, Wan-Su Bao, Chun Zhou, Mu-Sheng Jiang, and Hong-Wei Li
J. Opt. Soc. Am. B 36(3) B83-B91 (2019)
Yang Yu, Le Wang, Shengmei Zhao, and Qianping Mao
Opt. Express 29(2) 2227-2243 (2021)
Jiaao Li, Zhenhua Li, Zhongqi Sun, Ling Zhou, Yue Li, Haoyang Wang, and Haiqiang Ma
J. Opt. Soc. Am. B 40(8) 2108-2113 (2023)