Time–energy high-dimensional one-side device-independent quantum key distribution

Compared with full device-independent quantum key distribution(DI-QKD), one-side device-independent QKD(1s DI-QKD) needs fewer requirements, which is much easier to meet. In this paper, by applying recently developed novel time–energy entropic uncertainty relations, we present a time–energy high-dimensional one-side device-independent quantum key distribution(HD-QKD) and provide the security proof against coherent attacks. Besides, we connect the security with the quantum steering. By numerical simulation, we obtain the secret key rate for Alice's different detection efficiencies. The results show that our protocol can performance much better than the original 1s DI-QKD. Furthermore, we clarify the relation among the secret key rate, Alice's detection efficiency, and the dispersion coefficient. Finally, we simply analyze its performance in the optical fiber channel.     

Passive decoy-state quantum key distribution for the weak coherent photon source with finite-length key

Passive decoy-state quantum key distribution systems, proven to be more desirable than active ones in some scenarios,also have the problem of device imperfections like finite-length keys. In this paper, based on the WCP source which can be used for the passive decoy-state method, we obtain the expressions of single-photon error rates, single-photon counts, and phase error rates. According to the information of smooth min-entropy, we calculate the key generation rate under the condition of finite-length key. Key generation rates with different numbers of pulses are compared by numerical simulations. From the results, it can be seen that the passive decoy-state method can have good results if the total number of pulses reaches 1010. We also simulate the passive decoy-state method with different probabilities of choosing a pulse for parameter estimation when the number of pulses is fixed.     

InAs量子点在肖特基势垒二极管输运特性中的影响

在77到292K的范围内,系统研究了含InAs自组装量子点的金属-半导体-金属双肖特基势垒二极管的输运特性.随着温度上升,量子点的存储效应引起的电流回路逐渐减小.在测试温度范围内,通过量子点的共振隧穿过程在电流电压(I-V)曲线中造成台阶结构,且使电流回路随温度的上升急剧减小.根据肖特基势垒的反向I-V曲线,计算了势垒的反向饱和电流密度和平均理想因子.发现共振随穿效应使肖特基势垒在更大的程度上偏离了理想情况,而量子点的电子存储效应主要改变了肖特基势垒的有效势垒高度,从而影响了势垒的反向饱和电流密度 关键词： 自组装量子点 肖特基势垒 电流-电压特性     

辨析正交矩阵的特征值

指出关于正交矩阵的特征值的某个命题是错误的,分析了关于该命题的两种错误证明方法,说明了相应的正确结论.     

拉格朗日乘数法求解极值点的讨论

文中对拉格朗日乘数法极值点的求法进行了补充说明.     

COULOMB BLOCKADE OSCILLATIONS OF Si SINGLE-ELECTRON TRANSISTORS

Coulomb blockade oscillations of Si single-electron transistors, which are fabricated completely by the conventional photolithography technique, have been investigated. Most of the single-electron transistors clearly show Coulomb blockade oscillations and these oscillations can be periodic by applying negative voltages to the in-plane gates. A shift of the peak positions is observed at high temperatures. It is also found that the fluctuation of the peak spacing cannot be neglected.     

GaAs/AlxGa1-xAs量子阱能级结构设计与光谱分析

通过理论计算对用于量子阱红外探测器的GaAs/AlxGa1-xAs量子阱能级结构进行模拟设计,将不同生长结构的量子阱材料的光响应谱和光致荧光谱(PL)与计算结果进行比较.说明量子阱生长结构与量子阱能级结构的关系.欲使量子阱红外探测器的响应峰值在8μm附近,则需量子阱结构中阱宽为47nm,垒中Al含量为029.理论计算与测试结果符合得较好. 关键词：     

InAs自组装量子点GaAs肖特基二极管中的电流输运特性

设计了含有InAs自组装量子点(SAQDs)的新型金属半导体金属隧穿结构,研究了其直流输运特性,观察到了电流迟滞回路现象.这种回路现象是由于紧邻金属肖特基接触的量子点充电和放电引起的,也可以说是由外加电压控制的量子点的单电子过程引起的.分析了量子点总体的充放电特性,量子点中电子在高电场下隧穿出量子点的概率变化决定了量子点的放电过程,而充电过程是由流过量子点层的二极管正向电流决定.理论拟合结果显示充电过程主要由于量子点基态能级俘获电子照成的,激发态对量子点充放电过程只有微弱影响. 关键词： 迟滞现象 自组装量子点 单电子过程     

广义高斯分布的参数估计及其收敛性质

广义高斯分布是一类以Gaussian分布、Laplacian分布为特例的对称分布 ,它在信号处理和图像处理等领域都有广泛的应用 .本文采用矩估计方法讨论广义高斯分布的形状参数和尺度参数的估计问题 ,首先导出了矩和参数的关系表达式 ,然后由此提出参数估计方法 ,并对参数估计的收敛性质进行了分析 ,最后利用模拟实验对本文所提方法进行了验证 .