Calculation of Optical Conductivity of Anderson Impurity Model for Various Model Parameters

Materials classified as strongly-correlated systems often exhibit complex and fascinating properties due to interactions among electrons as well as between electrons and other constituents of the material. A common model to describe electronic system with strong on-site Coulomb interaction is Hubbard model. One very powerful approximation method for solving Hubbard model having been widely used over the last few decades is dynamical mean-field theory (DMFT). This method maps the original lattice problem into an impurity problem embedded in a self-consistent bath. Apart from the many variants of implementation of DMFT, it relies on using an impurity solver as part of its algorithm. In this work, rather than solving a Hubbard model, we propose to explore the impurity solver itself for solving a problem of metallic host doped with correlated elements, commonly referred to as Anderson impurity model (AIM). We solve the model using the distributional exact diagonalisation method. Our particular aim is to show how the metal-insulator transition (MIT) occurs in the system and how the phenomenon reflects in its optical conductivity for various model parameters.