纳米晶体结构与性能的模拟研究

通过分子动力学方法模拟纳米晶体（1—3nm）的结构．利用模拟的结果，进行了X射线衍射点阵常数、晶粒尺寸及点阵畸变的模拟计算，还计算了结合能及弹性模量等．结果表明纳米晶体无论是晶界和晶粒都与传统的粗晶粒晶体材料没有本质的区别，只是由于晶粒尺寸变小，以及晶界的体积分数等的作用，导致一系列的性能差异 关键词：     

Effects of Magnetic Field on the Valence Bond Property of the Double—Quantum—Dot Molecule

The effects of the magnetic field on the valence bond property of the double-quantum-dot molecule are numerically studied by the finite element method and perturbation approach because of the absence of cylindrical symmetry in the horizontally coupled dots.The calculation results show that the energy value of the ground state changes differently from that of the first excited state with increasing magnetic field strength,and they cross under a certain magnetic field.The increasing magnetic field makes the covalent bond state change into an ionic bond state,which agrees qualitatively with experimental results and and makes ionic bond states remain.The oscillator strength of transition between covalent bond states decreases distinctly with the increasing magnetic field strength,when the molecule is irradiated by polarized light.Such a phenomenon is possibly useful for actual applications.     

介观RLC并联电路量子效应

研究了介观RLC并联电路系统量子态随时间的演化，结果表明，在外加电源作用下，有耗散的RLC并联电路，系统将由初始的真空态演化到压缩态。     

In—Plane Propagation of Cavity Polaritons in a Quantum Semiconductor Microcavity

Considering that the coupling among the heavy-hole exciton,light-hole exciton and the cavity photon can form bipolaritons in a quantum semiconductor microcavity,we calculate the group velocities of the cavity polaritons at different incident angles using the coupling model of three harmonic oscillators.The result indicates that the group velocities of the low and middle branches of the cavity polaritons have extrema,but the group velocities of the high branch increase with the increasing incident angle.     

自组织生长锗硅量子点及其特性

半导体量子点的研究是当今物理学研究的热点之一．文章阐述了锗硅量子点自组织生长方法的基本原理和技术，并介绍了所制备的量子点材料的形貌结构、光学特性、电学特性及今后的发展方向．     

应变对纳米铜晶界迁移的影响

用分子动力学方法模拟了金属铜纳米双晶中晶界在应变作用下的迁移过程，晶界类型为〈11l〉倾侧∑19晶界。原子问相互作用力采用Finnis-Sinclair型EAM势计算。结果表明：平行于晶界方向的压应变可以促进晶界在相邻品界交互作用下发生迁移；垂直于晶界方向的压应变则不能对晶界迁移产生明显的效果。晶界迁移大致可分为两个阶段，前阶段晶界迁移缓慢，随晶界间距减小，晶界间交互作用加强，使晶界迁移显著加速。     

关于谐振子分立能级值的一种粗略导出方法

本文先介绍用不确定关系粗略计算一维线性谐振子零点能，然后再结合普朗克量子假设给出谐振子能级公式．     

金属熔体黏度与结构相关性的分子动力学模拟

运用EAM(embed atom method)作用势，采用非平衡分子动力学模拟获得Al熔体的偶分布函数与黏度数值随温度的变化曲线，偶分布函数的计算结果与实验值符合得较好.对模拟所得到的黏度数据编程实现黏度的Arrhenius公式拟合，得到激活能E.并利用模拟所得到的黏度值及激活能对Lennard-Jones(L-J)作用势进行修正，获得黏度与偶分布函数及原子间相互作用势之间的关系式，两条黏度拟合曲线与分子动力模拟结果符合得比较好，说明拟合程序的编写是比较成功的，实现了对L-J作用势的修正.该研究为金属及合金原子间相互作用势的建立提供了新的思路. 关键词： 非平衡分子动力学模拟 L-J作用势修正 Al熔体 结构与黏度相关性     

On the binding energies of excitons in polar quantum well structures in a weak electric field

The binding energies of excitons in quantum well structures subjected to an applied uniform electric field by taking into account the exciton longitudinal optical phonon interaction is calculated. The binding energies and corresponding Stark shifts for Ⅲ-Ⅴ and Ⅱ-Ⅵ compound semiconductor quantum well structures have been numerically computed. The results for GaAs/A1GaAs and ZnCdSe/ZnSe quantum wells are given and discussed. Theoretical results show that the exciton-phonon coupling reduces both the exciton binding energies and the Stark shifts by screening the Coulomb interaction. This effect is observable experimentally and cannot be neglected.     

考虑量子化效应的MOSFET阈值电压解析模型

根据改进后的三角势阱场近似，并考虑量子化效应，提出了一种基于物理的阈值电压解析模型，给出了MOSFET的阈值电压解析表达式，并与经典理论和数值模拟结果进行了比较. 关键词： 量子效应 阈值电压 反型层 表面势