Square-Gradient Scattering Mechanism in Surface-Corrugated Waveguides

In this work we study the surface scattering mechanisms from rough surfaces of a multimode quasi-1D waveguide (conducting quantum wires). The square-gradient scattering mechanism, which was missed in existing studies of the transport through surface-corrugated waveguides, is discovered. The main attention is paid to the interplay between the new mechanism and the known one, as well as its effect on the waveguide transport properties. For any value of the roughness height σ, the square-gradient terms in the expression for the wave-scattering length (electron mean-free path) are dominant, provided the correlation length Rc of the surface disorder is small enough.