A real-space rescaling treatment of the spectral properties of an adatom-contaminated crystal system

Abstract
An exact real-space rescaling transformation is used to calculate the local Green's functions and the densities of states for a semi-infinite nearest-neighbour tight-binding system with a adatom and an impurity atom located at an arbitrary distance from the surface. The influence of both the surface and impurity atom characteristics on the adatom density of states can be determined in a simple manner.