SPECIFIC PLATEAUS OF THE QUANTUM HALL-EFFECT INDUCED BY AN APPLIED BIAS

The spectrum and the eigenstates of a finite two-dimensional tight-bin ding electronic system, with Dirichlet boundary conditions, in a magne tic field and with an external linear potential are studied. The eigen states show an equipotential character, and may cross the plaquette in the direction perpendicular to the electric field. When leads are add ed to the plaquette, the channels carrying the current may be shortcut by equipotentials, resulting in additional plateaus situated between the usual integer-quantum-Hall-effect plateaus. This ideals confirmed by a numerical calculation within the four-terminal Landauer-Buttiker approach.