Solvable Model for Random Systems Including Off‐Diagonal Disorder

Abstract

Abstract Anderson's model for disordered systems is considered in the case where the transfer matrix elements fluctuate according to a Lorentzian distribution. It is shown that the exact ensemble averaged Green's function may be obtained if the energy level on each site depends linearly on the overlap integrals. Using this result the stability of amorphous Heisenberg ferromagnets is studied. The Weaire model of an amorphous covalent semiconductor with fluctuating matrix elements is considered. Numerical results for the density of states are given.