A High Dimensional Measurement-Device-Independent Quantum Key Distribution Scheme Based on Optical Quantum State Fusion and Fission

摘要

Measurement-device-independent quantum key distribution (MDI-QKD) not only eliminates all detector side channel attacks, but also doubles the secure transmission distance. To improve the performance of MDI-QKD, we propose a high dimensional encoding scheme. By a spatial-temporal mode conversion circuit and quantum state fusion operation, two polarization modes of two photons are converted into the temporal-polarization mode of one photon. Also, by adding a temporal-spatial mode conversion circuit to quantum state fission apparatus, the temporal-polarization mode of one photon can be split into two polarization modes of two photons. By these two processes, each of the two legitimate parties is able to send photons in high dimensional temporal and polarization modes, and the measurement server still performs Bell state measurements (BSMs) after states fission. Hence, the total output rate can be improved. In addition, one of the recovered polarization states keeps stable for channel noise. The numerical simulation results show that by this new scheme, the key generation rate increases by 2 approximate to 10 times and transmission distance increases by 6 approximate to 60 km for different polarization misalignment errors.