title: Polarization-basis tracking scheme for quantum key distribution using revealed sifted key bits.
abstract: The calibration of the polarization basis between the transmitter and receiver is an important task in quantum key distribution. A continuously working polarization-basis tracking scheme (PBTS) will effectively promote the efficiency of the system and reduce the potential security risk when switching between the transmission and calibration modes. Here, we proposed a single-photon level continuously working PBTS using only sifted key bits revealed during an error correction procedure, without introducing additional reference light or interrupting the transmission of quantum signals. We applied the scheme to a polarization-encoding BB84 QKD system in a 50 km fiber channel, and obtained an average quantum bit error rate (QBER) of 2.32% and a standard derivation of 0.87% during 24 h of continuous operation. The stable and relatively low QBER validates the effectiveness of the scheme.
authors.forename: Yu-Yang
authors.initials: YY
authors.lastname: Ding
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Hua
authors.initials: H
authors.lastname: Chen
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Li
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.forename: Zhen-Qiang
authors.initials: ZQ
authors.lastname: Yin
authors.forename: Guang-Can
authors.initials: GC
authors.lastname: Guo
authors.forename: Zheng-Fu
authors.initials: ZF
authors.lastname: Han