Conductance in disordered nanowires: Forward and backscattering

Abstract

We present an extensive work on the conductance as well as the transmission and reflection probabilities of disordered nanowires. We use a tight-binding Hamiltonian with diagonal disorder to describe the quantum wire, and a two-terminal Landauer-type formula for its conductance. For short wires, in the quasiballistic regime, we study the behavior of these quantities as a function of the degree of disorder and the Fermi energy of the electron, following their evolution when a channel disappears, finding an effective closing of the last opened channel (for strong disorder) before the actual closing energy. We analyze the influence of the length and width of the wire, noticing different transmission and reflection behavior depending on the incident channel. We have compared these results with the isotropic model predictions and found that these are satisfied only partially. © 1996 The American Physical Society.