ABSTRACT
In the last few years, there have been numerous investigations of near-threshold resonant tunneling through molecular-beam-epitaxy (MBE)-grown planar quantum-dot nanostructures. The manifestation of disorder-induced potential leads to weakly localized conducting channels through seemingly impenetrable barriers, which give rise to resonant-transport characteristics. This chapter shows that interface and surface roughness are sufficient to account for the resonant-transport features observed in the experimental devices. Initially, we simulate the device in the virtual-crystal approximation to determine whether the perfect device potential alone is sufficient to account for the resonant-tunneling features found in the experimental device characteristics. The purpose of the present investigation is to analyze the transport characteristics of an MBE-grown lateral single-gated quantum-dot device and assess the degree to which structural disorder affects its transport properties. The disorder-induced near-threshold resonant behavior we have investigated has been repeatedly observed in planar modulation-doped nanostructures.
