Fiber-based quantum secure direct communication without active polarization compensation  

作　　者：Xin Liu Di Luo Guangshen Lin Zihao Chen Chunfeng Huang Shizhuo Li Chengxian Zhang Zhenrong Zhang Kejin Wei 

机构地区：[1]Guangxi Key Laboratory for Relativistic Astrophysics,School of Physical Science and Technology,Guangxi University,Nanning,530004,China [2]Guangxi Key Laboratory of Multimedia Communications and Network Technology,School of Computer,Electronics,and Information,Guangxi University,Nanning,530004,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2022年第12期91-96,共6页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.62171144,and 11905065);Guangxi Science Foundation(Grant Nos.2021GXNSFAA220011,and 2021AC19384);Open Fund of IPOC(BUPT)(Grant No.IPOC2021A02);Innovation Project of Guangxi Graduate Education(Grant No.YCSW2022040)。

摘　　要：Quantum secure direct communication(QSDC)that allows people to directly transmit confidential information through insecure channels is an important branch of quantum communication.The widespread adoption of the QSDC demands the development of simple and stable systems.However,most of the existent QSDC systems involve a complex self-alignment process at the initial stage and additional hardware to compensate environmental disturbance.In this study,we present a fiber-based QSDC system without active polarization compensation.Our system comprises a stable transmitter and a novel Sagnac-Mach-Zehnder interferometer for security detection.This robust system simplifies the self-alignment and is immune to environmental disturbance.The robustness of the system was theoretically and experimentally verified,and low bit error rates in a 12 min continuous operation with an active polarization scrambler were attained.In addition,we performed a proof-of-principle QSDC demonstration,and a secrecy capacity of 3.43 kbps over a 5 km fiber with a detection bit error rate of 0.85%±0.07%and a quantum bit error rate of 0.42%±0.05%were achieved.Experimental results confirm the viability of the proposed QSDC system for practical applications.

关 键 词：quantum secure direct communication Sagnac-Mach-Zehnder interferometer without active polarization compensation 

分 类 号：P141[天文地球—天体物理]