Interface roughness scattering and electron mobility in quantum wires

We have theoretically investigated the influence of interface roughness on the scattering and mobility of electrons in very thin quantum wires, where all the electrons are in the lowest subband. In particular, the magnitude and electron concentration dependence of mobility are studied and shown to depend sensitively on the correlation length Λ and amplitude Δ of roughness. It is found that interface roughness scattering is drastically suppressed as the electron concentration increases, as in the case of impurity scattering when a realistic set of roughness parameters is chosen for edge quantum wire structures. General criteria to achieve ultra-high mobility in various quantum wire structures are also discussed.