Improving the performance of practical phase-matching quantum key distribution with advantage distillation

Phase-matching quantum key distribution (PM-QKD) is a promising protocol that can surpass the linear key-rate bound. Generally, inserting an advantage distillation (AD) step into PM-QKD can improve the secure key rate and transmission distance significantly in the asymptotic case. Here, we investigate the performance of practical PM-QKD systems with AD in the non-asymptotic case. Simulation results show that AD can dramatically improve the performance of practical PM-QKD systems. Moreover, we propose to estimate the information leakage using three mutually unbiased bases, namely X, Y and Z, to further enhance its performance, which demonstrates that using the error rates in X, Y and Z bases to estimate the information leakage can improve the secure key rate at high channel losses and misalignment errors.