BAND-STRUCTURE AND ELECTRICAL-CONDUCTIVITY OF DISORDERED LAYERED SYSTEMS

Employing the Kubo-Greenwood formula, the electrical conductivity of d isordered layered systems is formulated in terms of the (screened) Kor ringa-Kohn-Rostoker method and the coherent potential approximation. I t is shown that the elements of the electrical conductivity tensor can be described in terms of 'layer-diagonal' and 'layer-off-diagonal' co ntributions. In order to discuss effects of the underlying electronic structure on the electrical conductivity, but also to point out partic ular contributions to it, Bloch spectral functions are formulated. A s pin-polarized (relativistic) application of the present theory to non- collinear disordered magnetic multilayers allows one to discuss giant magnetoresistance (GMR) on an ab initio level in quite a general conte xt.