诱惑态在“双探测器”准单光子光源量子密钥分发系统中的应用

Decoy state quantum key distribution with dual detectorsheralded single photon source

现在诱惑态已被证明是一种可以大大提高量子密钥分发安全性能的现实可行的方法.由于考虑到现实应用中激光器在调制过程中的消光比不能做到100%,以及激光器固有的自发辐射因而使得制备真空态并不是一件容易的事情.因此本文将对理想情况下准单光子光源量子密钥分发系统应用中的诱惑态结论作了补充和扩展,提出了两个弱光强态的诱惑态方案和一个弱光强诱惑态方案.最后,将"双探测器"的理论应用在准单光子源(HSPS)光源系统中,使系统的安全传输距离可达到221·5km,比使用普通探测器的系统增加了约50km.

Decoy state has recently been proved as a useful method for substantially improving the performance of quantum key distribution （QKD）. Considering the imperfect extinction ratio and the spontaneous emission of the practical Laser, vacuum states are not prepared easily. So in this paper, the optimal situation of the decoy state protocol applied to the QKD system with heralded single photon source （HSPS） is complemented and extended. The two weak decoy state protocol and the one decoy state protocol are proposed. At last, the theory of ＂dual detectors＂ is combined with the QKD system with HSPS. In the simulation, the secure distance is up to 221.5 km, which is approximately 50 km more than that of the on-off detectors.