The charge transport in a dirty 2-dimensional electron system biased in the
presence of a lateral potential barrier under magnetic field is theoretically
studied. The quantum tunneling across the barrier provides the quantum
interference of the edge states localized on its both sides that results in
giant oscillations of the charge current flowing perpendicular to the lateral
junction. Our theoretical analysis is in a good agreement with the experimental
observations presented in Ref.8. In particular, positions of the conductance
maxima coincide with the Landau levels while the conductance itself is
essentially suppressed even at the energies at which the resonant tunneling
occurs and hence these puzzling observations can be resolved without taking
into account the electron-electron interaction.Comment: 6 pages, 4 figure
