The spectrum and the eigenstates of a finite two-dimensional tight-binding electronic system, with Dirichlet boundary conditions, in a magnetic field and with an external linear potential are studied. The eigenstates show an equipotential character, and may cross the plaquette in the direction perpendicular to the electric field. When leads are added 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 idea is confirmed by a numerical calculation within the four-terminal Landauer-Büttiker approach.

• Received 17 December 1996

DOI:https://doi.org/10.1103/PhysRevB.55.R13389