基于标记配对相干态光源的诱骗态量子密钥分配性能分析

摘要

A comprehensive analysis is made on the performance of decoy-state quantum key distribution with a heralded pair coherent state photon source from the effectiveness, stability and feasibility. The key generation rate, quantum bit error rate, and optimal signal intensity each as a function of secure transmission distance are simulated and analyzed by the three-intensity decoy-state method based on a heralded pair coherent state photon source with four groups of experimental data. Considering the intensity fluctuation, the stability of this method is simulated and discussed. Furthermore, the feasibility of the simple and easy method that is proposed with a heralded pair coherent state photon source is analyzed. The simulation results show that the key generation rate and secure transmission distance obtained from the decoy-state method with a heralded pair coherent state photon source are better than those obtained from the methods with a weak coherent state source and heralded single photon source. With the same intensity fluctuation, the heralded pair coherent state photon source is less stable than the heralded single photon source, but more robust than the weak coherent state source. However, the advantage in the effectiveness of the heralded single photon source can give rise to the shortage of the stability. Moreover, the two same modes of the heralded single photon source provide the feasibility to design a simple and easy passive decoy-state method.%从有效性、稳定性和可行性三个方面，对基于标记配对相干态光源的诱骗态量子密钥分配的性能进行了全面分析。采用四组实验数据对基于标记配对相干态光源的三强度诱骗态方案的密钥生成效率、量子比特误码率和最优信号态强度与安全传输距离之间的关系进行了仿真和分析；考虑到光源涨落，对方案的稳定性进行了讨论和仿真；并对基于标记配对相干态光源设计简单易实现方案的可行性进行了分析。结论表明：基于标记配对相干态光源的诱骗态方案性能在安全传输距离和密钥生成效率两方面都优于现有基于弱相干态光源和预报单光子源的诱骗态方案；在光源强度涨落相同条件下，标记配对相干态光源的稳定性逊于预报单光子源，而优于相干态光源。但是标记配对相干态光源在有效性上的优势可弥补其在稳定性上的不足；且标记配对相干态光源的双模特性为设计简单易实现的被动诱骗态方案提供了条件。