Tunneling into a Heavy Fermion System

Abstract

The discovery of an extremely high effective electron mass in CeAl3 by Andres et al in 1975 was the starting point for Heavy Fermion physics. One possible theory for explaining this heavy fermion behaviour is the Kondo lattice model which is investigated in this master thesis. With a slave boson mean field approach using Green’s functions, a set of mean field equations are derived and solved. The solutions of these equations determine the model behaviour as a function of various input parameters. In addition, a system where the Kondo lattice model is in close proximity to a Scanning Tunneling Microscope is considered. By the use of non-equilibrium Keldysh formalism, a tunneling current and differential conductance is calculated. The differential conductance is seen to map out the Kondo lattice density of states.