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Long-Distance Decoy-State Quantum Key Distribution

Date: 2007-01-12

   We demonstrate the decoy-state quantum key distribution (QKD) with one-way quantum communication in  polarization space over 102 km. Further, we simplify the experimental setup and use only one detector to  implement the one-way decoy-state QKD over 75 km, with the advantage to overcome the security loopholes due  to the efficiency mismatch of detectors. Our experimental implementation can really offer the unconditionally  secure final keys. We use 3 different intensities of 0, 0.2, and 0.6 for the light sources in our experiment. In order  to eliminate the influences of polarization mode dispersion in the long-distance single-mode optical fiber, an  automatic polarization compensation system is utilized to implement the active compensation.( Phys. Rev. Lett.
98, 010505 (2007) )