A long-distance quantum key distribution scheme based on pre-detection of optical pulse with auxiliary state  

作　　者：权东晓 朱畅华 刘世全 裴昌幸 

机构地区：[1]State Key Laboratory of Integrated Services Networks, Xidian University

出　　处：《Chinese Physics B》2015年第5期252-256,共5页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.61372076);the Programme of Introducing Talents of Discipline to Universities,China(Grant No.B08038);the Fundamental Research Funds for the Central Universities,China(Grant No.K5051201021)

摘　　要：We construct a circuit based on PBS and CNOT gates, which can be used to determine whether the input pulse is empty or not according to the detection result of the auxiliary state, while the input state will not be changed. The circuit can be treated as a pre-detection device. Equipping the pre-detection device in the front of the receiver of the quantum key distribution （QKD） can reduce the influence of the dark count of the detector, hence increasing the secure communication distance significantly. Simulation results show that the secure communication distance can reach 516 km and 479 km for QKD with perfect single photon source and decoy-state QKD with weak coherent photon source, respectively.We construct a circuit based on PBS and CNOT gates, which can be used to determine whether the input pulse is empty or not according to the detection result of the auxiliary state, while the input state will not be changed. The circuit can be treated as a pre-detection device. Equipping the pre-detection device in the front of the receiver of the quantum key distribution （QKD） can reduce the influence of the dark count of the detector, hence increasing the secure communication distance significantly. Simulation results show that the secure communication distance can reach 516 km and 479 km for QKD with perfect single photon source and decoy-state QKD with weak coherent photon source, respectively.

关 键 词：quantum key distribution PRE-DETECTION secure communication distance decoy state 

分 类 号：O413[理学—理论物理] TN918.4[理学—物理]