A Security Proof of Measurement Device Independent Quantum Key Distribution： From the View of Information Theory

Although some ideal quantum key distribution protocols have been proved to be secure, there have been some demonstrations that practical quantum key distribution implementations were hacked due to some real-life imperfections. Among these attacks, detector side channel attacks may be the most serious. Recently, a measurement device independent quantum key distribution protocol [Phys. Rev. Lett. 108 （2012） 130503] was proposed and all detector side channel attacks are removed in this scheme. Here a new security proof based on quantum information theory is given. The eavesdropper＇s information of the sifted key bits is bounded. Then with this bound, the final secure key bit rate can be obtained.     

一种集成QKD服务的GPON网络架构(英文)

提出一种安全增强的集成量子密钥分配业务的吉比特无源光网络架构.使用特殊光分支器件和以现场可编程门阵列芯片控制的光网络单元动态绑定实现的上行交替时分多址接入的方式,使得量子信道的噪声在可接受范围,从而让量子密钥加密和传统业务能够共存.实验表明在传统业务正常运行的情况下,超过20km光纤传输距离的安全量子比特误码率限制下的平均安全密钥速率达到2.12kbps.该网络架构易于扩展,且比现行无源光网络有更好的安全性.     

气体分子对甲烷水合物稳定性的影响

通过B3LYP方法, 在6-31G(d,p)水平下, 分别优化了结构I型甲烷水合物十二面体和十四面体晶穴结构. 结果表明, CH4分子使晶穴的相互作用能降低, 增强了晶穴的稳定性. 计算了晶穴中甲烷分子C—H键的对称伸缩振动频率, 计算结果与实验值相符合. 研究发现CH4分子影响晶穴中氧原子的电荷分布, 从而增强了氢键的稳定性. 通过分子动力学方法研究水合物晶胞中气体分子的占有率对水合物稳定性的影响, 进一步说明气体分子对水合物晶穴稳定性的重要作用.