Spatially resolved measurements near the breakdown of the quantum hall effect

Abstract

We have measured the generation and relaxation of hot electrons along their drift direction near the breakdown of the quantum Hall effect. The dissipative resistivity of the two-dimensional electron system (2DES) is measured as a function of the distance from the electron injection. By injecting hot electrons into a Hall bar at subcritical currents, the relaxation process was analyzed. The inelastic relaxation length was found strongly correlated with the elastic mean free path. Thus, we conclude that the relaxation is triggered by Coulomb scattering.The injection of electrons at supercritical current levels allowed to monitor the evolution of the breakdown along the drift direction. After a linear increase of the resistivity with the drifting distance, a rather steep increase of disspation occurs. The linear increase is attributed to tunneling between Landau levels, whereas the steep increase is likely due to an avalanche-like multiplication of hot electrons.KeywordsQuantum Hall EffectWire ArrayResistivity ProfileRelaxation LengthDrift DirectionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.