Yu Zong-Wen, Hu Xiao-Long, Jiang Cong, Xu Hai, Wang Xiang-Bin
State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing, 100084, People's Republic of China.
Data Communication Science and Technology Research Institute, Beijing, 100191, People's Republic of China.
Sci Rep. 2019 Feb 28;9(1):3080. doi: 10.1038/s41598-019-39225-y.
Recently, the twin field quantum key distribution (TF-QKD) protocols have been investigated extensively. In particular, an efficient protocol for TF-QKD with sending or not sending the coherent state has been given in. Here in this paper, we present results of practical sending-or-not-sending (SNS) twin field quantum key distribution. In real-life implementations, we need consider the following three requirements, a few different intensities rather than infinite number of different intensities, a phase slice of appropriate size rather than infinitely small size and the statistical fluctuations. We first show the decoy-state method with only a few different intensities and a phase slice of appropriate size. We then give a statistical fluctuation analysis for the decoy-state method. Numerical simulation shows that, the performance of our method is comparable to the asymptotic case for which the key size is large enough. Our method can beat the PLOB bound on secret key capacity. Our results show that practical implementations of the SNS quantum key distribution can be both secure and efficient.
最近，双场量子密钥分发（TF-QKD）协议受到了广泛研究。特别是，文献中给出了一种发送或不发送相干态的TF-QKD高效协议。在本文中，我们展示了实际的发送或不发送（SNS）双场量子密钥分发的结果。在实际实现中，我们需要考虑以下三个要求：几种不同强度而非无限数量的不同强度、适当大小的相位片而非无限小的大小以及统计涨落。我们首先展示仅具有几种不同强度和适当大小相位片的诱骗态方法。然后我们对诱骗态方法进行统计涨落分析。数值模拟表明，我们方法的性能与密钥大小足够大的渐近情况相当。我们的方法可以突破关于秘密密钥容量的PLOB界限。我们的结果表明，SNS量子密钥分发的实际实现可以既安全又高效。
