非对易相空间中各向同性谐振子的能级分裂

非对易空间的效应是出现在弦尺度下的一种物理效应. 本文介绍了量子力学非对易空间的代数关系; 讨论了非对易相空间中服从玻色-爱因斯坦统计的粒子的连续性条件, 最后给出了非对易相平面和非对易相空间中的线性谐振子的能级分裂.     

金属介质在时域有限差分中的几种处理方法

金属在“超颖物质”中有重要应用，分析和仿真金属介质很有意义. 对比了时域有限差分(FDTD)中金属介质的三种计算方法：ADE(Auxiliary Differential Equation), PLRC(Piecewise Linear Recursive Convolution) 和Sakoda提出的方法. 通过数值验证，发现ADE和PLRC的数值结果完全相同. Sakoda的方法在计算卷积时采用台阶近似，有一定误差.改进Sakoda方法的卷积计算后，结果与其他两种方法完全相同. 关键词： 超颖物质 金属 FDTD ADE PLRC     

Guiding mode in elliptical core microstructured polymer optical fiber

A kind of microstructured polymer optical fiber with elliptical core has been fabricated by adopting in- situ chemical polymerization technology and the secondary sleeving draw-stretching technique.Microscope photography demonstrates the clear hole-structure retained in the fiber.Though the holes distortion is visible,initial laser experiment indicates that light can be strongly confined in the elliptical core region, and the mode field is split obviously and presents the multi-mode characteristic.Numerical modeling is carried out for the real fiber with the measured parameters,including the external diameter of 150μm,the average holes diameter of 3.3μm,and the average hole spacing of 6.3μm by using full-vector plane wave method.The guided mode fields of the numerical simulation are consistent with the experiment result. This fiber shows the strong multi-mode and weak birefringence in the visible and near-infrared band,and has possibility for achieving the fiber mode convertors,mode selective couplers and so on.     

Van der Waals interactions and Photoelectric Effect in Noncommutative Quantum Mechanics

We calculate the long-range Van der Waals force and the photoelectric cross section in a noncommutative setup. It is argued that non-commutativity effects could not be discerned for the Van der Waals interactions. The result for the photoelectric effect shows deviation from the usual commutative one, which in principle can be used to put bounds on the space-space non-commutativity parameter.     

He-McKellar-Wilkens Effect in Noncommutative Space

The He-McKellar-Wilkens （HMW） effect in non-commutative （NC） space is studied. By solving the Dirac equations on NC space, we obtain topological HMW phase in NC space where the additional terms related to the space non-commutativity are given explicitly.     

Maxwell理论的电磁对偶性

本文主要回顾了电磁场的对偶性和电荷量子化解释,并把电磁场的对偶性推广到了一般线性介质状况,讨论了磁单极及其整体规范变换,并给出了Dirac磁单极产生的磁矢势的普遍表达式;最后给出了Maxwell方程的U（1）对称性及其对偶性的费米子描述方法。     

Investigation of the characteristics of GIDL current in 90nm CMOS technology

A specially designed experiment is performed for investigating gate-induced drain leakage (GIDL) current in 90nm CMOS technology using lightly-doped drain (LDD) NMOSFET. This paper shows that the drain bias $V_{\rm D}$ has a strong effect on GIDL current as compared with the gate bias $V_{\rm G}$ at the same drain--gate voltage $V_{\rm DG}$. It is found that the difference between $I_{\rm D}$ in the off-state $I_{\rm D}-V_{\rm G}$ characteristics and the corresponding one in the off-state $I_{\rm D}-V_{\rm D}$ characteristics, which is defined as $I_{\rm DIFF}$, versus $V_{\rm DG}$ shows a peak. The difference between the influences of $V_{\rm D}$ and $V_{\rm G}$ on GIDL current is shown quantitatively by $I_{\rm DIFF}$, especially in 90nm scale. The difference is due to different hole tunnellings. Furthermore, the maximum $I_{\rm DIFF }$($I_{\rm DIFF,MAX})$ varies linearly with $V_{\rm DG}$ in logarithmic coordinates and also $V_{\rm DG}$ at $I_{\rm DIFF,MAX}$ with $V_{\rm F}$ which is the characteristic voltage of $I_{\rm DIFF}$. The relations are studied and some related expressions are given.     

Hot-carrier degradation for 90nm gate length LDD-NMOSFET with ultra-thin gate oxide under low gate voltage stress

The hot-carrier degradation for 90~nm gate length lightly-doped drain (LDD) NMOSFET with ultra-thin (1.4~nm) gate oxide under the low gate voltage (LGV) (at V_g=V_th, where V_th is the threshold voltage) stress has been investigated. It is found that the drain current decreases and the threshold voltage increases after the LGV (V_g=V_th stress. The results are opposite to the degradation phenomena of conventional NMOSFET for the case of this stress. By analysing the gate-induced drain leakage (GIDL) current before and after stresses, it is confirmed that under the LGV stress in ultra-short gate LDD-NMOSFET with ultra-thin gate oxide, the hot holes are trapped at interface in the LDD region and cannot shorten the channel to mask the influence of interface states as those in conventional NMOSFET do, which leads to the different degradation phenomena from those of the conventional NMOS devices. This paper also discusses the degradation in the 90~nm gate length LDD-NMOSFET with 1.4~nm gate oxide under the LGV stress at V_g=V_th with various drain biases. Experimental results show that the degradation slopes (n) range from 0.21 to 0.41. The value of n is less than that of conventional MOSFET (0.5-0.6) and also that of the long gate length LDD MOSFET (\sim0.8).     

顶端ZnO纳米结构对GaN基LED光提取效率的影响

为了提高GaN基蓝光LED的光提取效率,本文建立了LED顶面分别铺设ZnO纳米柱和纳米锥结构的两种模型,利用时域有限差分法对两种模型进行仿真并对结果进行了比较.仿真结果表明,ZnO纳米结构的各项几何结构参量(包括排列周期P、高度L、宽度W以及斜率k等),对LED顶端光提取效率影响显著.仿真分别得到了两种结构的最佳模型,通过比较,LED顶面纳米柱和纳米锥结构对光提取效率的提高效果相近,其最佳提取效率分别增强至无任何结构时的2.5倍和2.3倍.同时,通过对各项参量扫描获得的对光提取效率的变化曲线进行了分析,并给出了相应相应的理论解释.这些模型优化和理论分析对实际的高性能GaN基LED的设计制造有着指导意义.     

SU(2)tWZW模型的基本问题

本文给出了SU(2)_tWZW模型j₃=1情况下基本问题的解,并给出了一般求解的方法.我们同时也找到了SU(2)_tWZW模型的交叉矩阵与SL(2,q)量子群的辫子矩阵(即量子拉卡系数)的明显关系.