Scalapino This project is for work aimed at calculating and understanding the physical properties of strongly-interacting many-electron systems. It includes both numerical and phenomenological analytic calculations for basic lattice Hamiltonians such as the Heisenberg, Hubbard, and t-J models. These models exhibit a wide range of phases including antiferromagnetism, charge density waves, superconductivity, domain wall formation, and phase separation that are descriptive of similar behavior in many materials with technologically important magnetic and superconducting properties. The goal of this work is to understand the basic mechanisms and competition that lead to this rich array of phases and to develop reliable ways of calculating their properties. %%% Many novel materials with magnetic and superconducting properties of potential technological and commercial importance, such as high-temperature superconductors, cannot be adequately described by theoretical models for the electronic structure that assume a mean-field behavior for the interactions between electrons. Such systems require the use of models which incorporate explicit correlation effects between electrons. This research aims to improve our understanding of the electronic properties of materials where many-electron effects dominate the interesting electronic properties, and will be critical in advancing the development and use of such technologically important materials. ***
