Signatures of bandlike tunneling in granular nanowires

We explore the problem of tunneling through disorderd nanowires, comprised of a random distribution of metallic grains, by means of a many-body model that captures the essential physics of the system. The random configuration of grains gives rise to a smooth bandlike set of states that mediates current flow through the nanowires. Analytical and numerical calculations show the characteristic signature of this unusual bandlike transport to be a quadratic variation of the current as a function of the applied voltage (i.e., I∼V2), a variation that is clearly observed in experimental studies of Pt/C composite nanowires.