CORNER DISSIPATION IN QUANTUM HALL SYSTEMS

A description of the onset of dissipation in the integer quantum Hall effect is given, where the electric field across the sample is express ed through a time dependent vector potential. This brings the essentia lly time dependent, non-stationary nature of the problem into focus. T he electric field induces transitions between the levels of the disord er broadened Landau band. Above a critical electric field the particle s are driven upwards in energy space beyond the Fermi level, which lea ds to dissipation since the accumulated energy is lost to the heat bat h after tau(in), the time between two inelastic events. Thus the dissi pated power is obtained without the use of the traditional (linear res ponse) transport formulae. As an application we investigate the dissip ation in the corner region of a Hall bar. The results are in reasonabl e accordance with recent experiments exploiting the fountain pressure effect.