INFLUENCE OF POTENTIAL BARRIERS, DISORDER AND DISSIPATION ON THE QUANTUM HALL-EFFECT

We investigate the influence of coherent and incoherent scattering on magnetotransport in the quantum Hall regime. Our studies are based on the Landauer transport theory allowing to treat general sample geometr ies and distributions of scatterers. Dissipation is implemented by cou pling the sample to auxiliary dephasing: electron reservoirs. The pres ented numerical results for elastic scattering due to disorder and pot ential barriers confirm the importance;ce of edge-state transport in t he QH regime. The stability of the quantum Hall plateaus with respect to short-range disorder is shown to be strongly affected by the charge -neutrality condition. The Hall plateaus turn out to be surprisingly r obust against dissipation in the commonly used four-or six-terminal co nfigurations. Tile stabilization of the current distribution in dissip ative systems is exploited: to describe the QH situation using a finit e weakly dissipative quantum wire.