Cluster simulation of the lattice Anderson model

Abstract

The ground-state and thermodynamic properties of the lattice Anderson model have been studied on a four-site, tetrahedral cluster. There are two nondegenerate orbitals on each site (c and f). The Hamiltonian of the model is diagonalized exactly (numerically) for systems with four through nine electrons. Thermodynamic properties are studied with use of a cannonical ensemble. This paper is primarily concerned with the small-hybridization, strong-interaction region of parameters. We vary the energy of the f level for fixed values of the other parameters. A complex variety of systems are simulated involving five classes or regions of behavior, defined in terms of the f-level occupation.