Theory of Electrons in Solids

9421966 Sham该项目是固态系统中非线性光学过程时间演化的理论研究。 该理论要求同时考虑电子与强电磁场的相互作用、电子之间的相互作用以及电子与其宿主环境的相互作用。 特别注意的是光的偏振和电子的自旋动力学之间的相互作用。 将研究以下系统：III-V族半导体异质结构（光电器件的有前途的系统），II-VI族磁性半导体异质结构（对可见光和磁光器件很重要）和轻元素化合物（表现出强相关电子的特性）。 所采用的方法是场论的，用图解表示。 这些结果预计将是一个统一的解释，在这些固态系统的每一类中观察到的广泛的非线性光学现象，新的行为的预测，并通过光学过程，可以测试电子理论的强电子相关的更深入的理解。 %%% 这项工作涉及模拟光与几种固体系统的相互作用，包括层状（复合）半导体系统和轻元素化合物。 这种相互作用提供了一种测量这些系统中电子特性的方法，并形成了制造超快光学器件的基础。 光与待研究的某些类别中的电子性质相互作用，而与其他类别中的磁性相互作用。 这些结果有望成为对三类固态系统中广泛观察到的非线性光学现象的统一解释，对新行为的预测，以及对电子-电子相互作用的更深入理解，这是许多材料背后理论的关键。 ***

9421966 Sham This project is a theoretical study of the time evolution of the nonlinear optical processes in solid state systems. The theory requires taking into account simultaneously the interaction of electrons with intense electromagnetic fields, the interaction among the electrons, and the interaction of the electron with its host environment. Special attention is paid to the interplay between the polarization of light and the spin dynamics of the electrons. The following systems will be studied: III-V nonmagnetic semiconductor heterostructures (promising systems for optoelectronic devices), II-VI magnetic semiconductor heterostructures (important for visible optical and magneto-optical devices), and light element compounds (exhibit properties of strongly correlated electrons). The approach adopted is field theoretic, with a diagrammatic representation. The results are expected to be a unified explanation for a wide range of observed nonlinear optical phenomena in each class of these solid state systems, predictions of new behavior, and a deeper understanding of strong electron correlation through optical processes which can test electron theories. %%% This work involves modeling the interaction of light with several solid systems, including layered (composite) semiconducting systems and light element compounds. This interaction provides a means of measuring the electronic properties in these systems and forms a basis for making ultrafast optical devices. The light interacts with the electronic properties in certain classes to be studied and with magnetic properties in others. The results are expected to be a unified explanation for a wide range of observed nonlinear optical phenomena in three classes of solid state systems, predictions of new behavior, and a deeper understanding of the electron-electron interactions, which are a key to the theory behind many materials. ***