Method for computing the electronic structure of thin crystalline films with disordered surface atoms

We present a Green's function method for computing the electronic structure of a crystalline film in which the surface atoms are disordered. The disorder is taken into account by considering an ensemble of random displacement configurations. We use a uninodal approximation to construct a general formalism for the method and obtain a determinant equation and expression for the density of states, permitting a numerical solution to the spectral problem. We discuss which features of the surface electronic structure are due to displacement disorder in the surface region of the crystal, and in what systems such disorder can be realized.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 81–88, August, 1988.We thank G. V. Vol'f for some useful discussions.