Secure quantum communication in the presence of phase- and polarization-dependent loss

作     者：Chenyang Li Marcos Curty Feihu Xu Olinka Bedroya Hoi-Kwong Lo 

作者机构：Center for Quantum Information and Quantum Control Department of Electrical & Computer Engineering and Department of Physics University of Toronto Toronto Ontario M5S 3G4 Canada Escuela de Ingeniería de Telecomunicación Department of Signal Theory and Communications University of Vigo Vigo E-36310 Spain Shanghai Branch Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Shanghai 201315 China 

出 版 物：《Physical Review A》 (Phys. Rev. A)

年 卷 期：2018年第98卷第4期

页      面：042324-042324页

核心收录：

基　　金：1000 Young Talent Program of China Huawei Technologies Canada Co., Ltd Horizon 2020 Framework Programme, H2020 National Research Council, NRC Natural Sciences and Engineering Research Council of Canada, NSERC Ministerio de Economía y Competitividad, MINECO Horizon 2020, (675662) European Regional Development Fund, FEDER, (TEC2014-54898-R, TEC2017-88243-R) Fundamental Research Funds for the Central Universities 

主　　题：Quantum cryptography 

摘      要：Silicon photonics holds the promise of the miniaturization of quantum communication devices. Recently, silicon chip optical transmitters for quantum key distribution (QKD) have been built and demonstrated experimentally. Nonetheless, these silicon chips suffer substantial phase- and polarization-dependent loss (PDL) which, if unchecked, could compromise the security of QKD systems due to overestimation of the secret key rate. Here, first, we restore the security by regarding single photons without phase and polarization dependence as untagged and secure qubits. Next, by using a postselection technique, we implement a secure QKD protocol that provides a high key generation rate even in the presence of severe phase- and polarization-dependent loss. Our solution is simple to realize in a practical experiment, as it does not require any hardware modification.