Quantum Diffusion and Localization in Disordered Electronic Systems

Abstract

The diffusion of electronic wave packets in one-dimensional systems with on-site, binary disorder is numerically investigated within the framework of a single-band tight-binding model. Fractal properties are incorporated by assuming that the distribution of distances $\ell$ between consecutive impurities obeys a power law, $P(\ell )\sim {\ell }^{-\alpha }$. For suitable ranges of $\alpha$, one finds system-wide anomalous diffusion. Asymmetric diffusion effects are introduced through the application of an external electric field, leading to results similar to those observed in the case of photogenerated electron-hole plasmas in tilted InP/InGaAs/InP quantum wells.

RevTex4, 6 pages, 6 .eps figures: published version