ABSTRACT
We have investigated the non-linear current transport near the Quantum Hall Effect (QHE) breakdown at a variety of AIII-BV semiconductor interfaces (GaAs/GaAlAs and InGaAs/InAlAs heterojunction, InSb grain boundaries). Although the material parameters as band gap and effective electron mass are rather different in the systems investigated, the switching from non-dissipative QH conduction to dissipative current transport has very striking similarities. In particular, a hysteresis of the longitudinal resistance Rxx dependence on the filling factor near the flanks of the QH plateaux was observed in a distinct current range. The sudden changes in Rxx were accompanied by sudden drops of the Hall resistance below quantized values in all systems. Time resolved measurements reveal the bistable character of the dissipative and non-dissipative states. We attribute this effect to hot electrons generated in current- carrying filaments. These filaments develop below a critical electron density of about 3x1015m-2 due to impurity potential fluctuations and/or by geometrical patterning of narrow current channels.
