GIANT BACKSCATTERING RESONANCES IN EDGE-STATE TRANSPORT THROUGH QUANTUM DOTS

We consider the origin of striking resonances, observed in the low-tem perature magneto-resistance of submicron-sized quantum dots. The magne tic-field positions of the resonances are correlated to the depopulati on of Landau levels in the dots, while their amplitude can correspond to a near-complete reflection of the applied current. In order to dete rmine the origin of these features, we formulate a model for edge-stat e scattering in quantum dots which properly accounts for the magnetic- field-dependent evolution of their self-consistent potential profile. The resonances are thus ascribed to a sudden increase in back scatteri ng, mediated by edge states trapped inside the dot. A similar treatmen t which ignores the high-held evolution of the dot profile is unable t o reproduce the resonances, which we therefore conclude provide an imp ortant demonstration of the role of self-consistent effects in mesosco pic systems.