Twin-field quantum key distribution with discrete phase randomization

作     者：Wang, Rong Yin, Zhen-Qiang Lu, Feng-Yu Wang, Shuang Chen, Wei Huang, Wei Xu, Bing-Jie Guo, Guang-Can Han, Zheng-Fu 

作者机构：Cas Key Laboratory of Quantum Information Cas Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of China Hefei230026 China State Key Laboratory of Cryptology P. O. Box 5159 Beijing100878 China Science and Technology on Communication Security Laboratory Institute of Southwestern Communication Chengdu Sichuan610041 China 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2019年

核心收录：

主　　题：Random processes 

摘      要：Twin-field quantum key distribution (TF-QKD) and its variant protocols are highly attractive due to its advantage of overcoming the well-known rate-loss limit for QKD protocols, i.e. R 6 log2(1-η) with η standing for the channel transmittance. These protocols can be divided into two types, with phase randomization from [0, π] and without phase randomization in code mode. Here, we generalize the two types into a unified protocol, where Alice and Bob prepare coherent states with 2M (M ∈-1, 2, 3...}) different phases. Moreover, our security proof indicates that the achievable distance becomes longer with M exponentially increasing, as a trade-off, the secret key rate will be lowered at short distance due to phase postselection. Numerical simulations show that the protocol with M = 2 may be the best choice in experiment. Copyright © 2019, The Authors. All rights reserved.