Size-dependent quantised breakdown of the dissipationless quantum Hall effect in narrow channels

Abstract

A model involving quasi-elastic inter-Landau-level scattering is proposed to explain the three main features of recent experiments by Bliek and co-workers on the dissipative transverse magnetoresistance of the two-dimensional electron gas in GaAs/(AlGa)As heterostructures in which there is a narrow constriction in the conducting channel. These features are the high breakdown current densities observed, the magnetic field values of the 'quantum' steps in the magnetoresistance and the quantised values of the magnetoresistance.