Efficient quantum key distribution via single-photon two-qubit states
Jindong Wang, Zhengjun Wei, Hui Zhang, Xiaojuan Qin, Xiaobao Liu, Zhi‐Ming Zhang, Changjun Liao, Songhao Liu · Journal of Physics B Atomic Molecular and Optical Physics · 2010
We propose a scheme for quantum key distribution, in which single photons are encoded with polarization states and then divided and delayed to encode phase differences between two sequential pulses. In an example, the BB84 and DPS (differential phase shift) protocols are combined to achieve single-photon two-qubit quantum key distribution. This scheme can increase the key generation efficiency up to 7/6, higher than that of the conventional single-photon one-qubit quantum key distribution scheme.