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. ***
