Polarization basis tracking scheme for quantum key distribution with   revealed sifted key bits
  Calibration of the polarization basis between the transmitter and receiver is an important task in quantum key distribution (QKD). An effective polarization-basis tracking scheme will decrease the quantum bit error rate (QBER) and improve the efficiency of a polarization encoding QKD system. In this paper, we proposed a polarization-basis tracking scheme using only unveiled sifted key bits while performing error correction by legitimate users, rather than introducing additional reference light or interrupting the transmission of quantum signals. A polarization-encoding fiber BB84 QKD prototype was developed to examine the validity of this scheme. An average QBER of 2.32% and a standard derivation of 0.87% have been obtained during 24 hours of continuous operation. 
Yu-Yang Ding, Wei Chen, Hua Chen, Chao Wang, Ya-Ping li, Zhen-Qiang   Yin, Shuang Wang, Guang-Can Guo, Zheng-Fu Han
quant-ph physics.optics