9402923 Reiter This U.S.-Brazil award will support a collaboration between Drs. George Reiter of the University of Houston, Houston, TX and F.C. Barreto of the Universidade Federal de Minas Gerais, Brazil. The goal of the project is to form an international collaboration between scientists experienced in the treatment of low-dimensional magnetic systems, and to resolve fundamental issues in the dynamics of spin and charge that have arisen in the study of high temperature superconductors. No generally accepted theory exists of the mechanism for superconductivity nor of the dynamics of the normal phase in the high Tc superconductors. Two key issues are whether or not the carriers in the materials can be described as a strongly correlated Fermi liquid, and whether or not the carriers would phase separate if not limited by the Coulomb interaction from doing so. There is no agreed upon answer to the first question. While the answer to the second question is yes, at some values of the parameters for the models that have been used to describe the Cu-O planes the situation remains unclear for the actual physical values. A treatment of the three band (Emery) model is proposed, which has the potential of answering both of the above questions. ***
