Modern Methods in Theory of Strongly Correlated Electron Systems

Thursday, March 28, 2024
4:00 PM - 5:00 PM
TRC123

 Modern Methods in Theory of Strongly Correlated Electron Systems

Dr. Igor Kogoutiouk

Department of Physics and Astronomy, Minnesota State University - Mankato

ABSTRACT: 

There is a wide class of materials with narrow open d- and f- shells that can exhibit unique physical properties: temperature and pressure induced metal-insulator transitions, giant thermoelectric power, positive and negative magnetoresistance, various types of charge and magnetic ordering and high temperature superconductivity. It was discovered that profound novel effects in such materials are caused by strong interelectron correlations, which can’t be adequately described within classical electron band theory.

In this presentation some of the modern methods of theoretical investigation of strongly correlated electrons are described. They include: one-particle, and two-particle Green Functions; Irreducible Green Functions; Density Field Theory, Coherent Potential Approximation and Dynamical Mean-Field Theory. The achievements and limitations of such theoretical approaches are discussed. The results, obtained by some of their applications to Hubbard, Extended Hubbard, Impurity Anderson and Periodic Hubbard-Anderson models demonstrate the possibility of splitting energy spectrum, charge and magnetic ordering under the influence of external perturbations.