Theory of Electrons in Solids

这个项目是对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宿主环境的相互作用。特别注意光的偏振和电子的自旋动力学之间的相互作用。以下系统将被研究：III-V非磁性半导体异质结构（光电子器件的有前途的系统），II-VI磁性半导体异质结构（重要的可见光学和磁光器件），以及轻元素化合物（表现出强相关电子的性质）。所采用的方法是场论的，用图表示。研究结果有望对这些固体系统中观察到的各种非线性光学现象提供统一的解释，预测新的行为，并通过可以测试电子理论的光学过程对强电子相关性有更深入的理解。这项工作包括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。这种相互作用为测量这些系统的电子特性提供了一种手段，并为制造超快光学器件奠定了基础。光与某些待研究类别的电子性质相互作用，与其他类别的磁性相互作用。研究结果有望统一解释在三类固态系统中观察到的广泛的非线性光学现象，预测新的行为，以及对电子-电子相互作用的更深入的理解，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. ***