Asymmetric mode-pairing quantum key distribution with advantage distillation

Mode-pairing quantum key distribution (MP-QKD) is an excellent scheme that can exceed the repeaterless rate-transmittance bound without complex phase locking. Nevertheless, MP-QKD usually needs to ensure that the communication distances of the two channels are equal. To address the problem, the asymmetric MP-QKD protocol is proposed. In this paper, we enhance the performance of the asymmetric MP-QKD protocol based on the advantage distillation (AD) method without modifying the quantum process. The simulation results show that the AD method can extend the communication distance by about 70 km in the case of asymmetry. And we observe that as the misalignment error increases, the AD method further increases the expandable communication distance. Our work can further enhance the robustness and promote the practical application of the asymmetric MP-QKD.