Spectral Densities For Electronic Surface States

Discusses the transfer matrix approach for the calculation of the spectral density of states of solids with cleaved surfaces. The method is applied explicitly to a simple model of a hybridized s-d system: a cubic solid with two orbitals per site, one derived from a narrow d-like band and the other from a wide s-like band of states. The narrow band acquires an appreciable fraction of its width from hybridization with the wide band. The authors discuss the effect of relaxation on the creation of localized surface states. Relaxation in either the diagonal matrix element or the direct d-d overlap integral, at the surface, may lead to the splitting of localized states from the continuum. No such effect is observed upon relaxing the s-d nearest neighbour overlap integral. The present method is concluded to constitute a viable alternative to existing methods for the calculation of surface electronic properties.10685185