INFLUENCE OF SURFACE-ROUGHNESS ON THE CONDUCTIVITY OF METALLIC AND SEMICONDUCTING QUASI-2-DIMENSIONAL STRUCTURES

At low temperature, the conductivity sigma of metallic films or of semiconducting quantum wells is limited by surface-roughness scattering. The expression for sigma includes an autocorrelation function (ACF) associated with the roughness. We report a theoretical study of the dependence of sigma on the shape, and the correlation length xi of the ACF. It is concluded that sigma depends strongly on the choice of the ACF for xi >> k(F)-1, where k(F) is the Fermi wave vector. For metallic films, the mean variation of sigma with thickness d cannot be approximated by the usual power law, sigma is-proportional-to d(s); similar effects are obtained for semiconducting quantum wells.