Spatially resolved monitoring of the evolution of the breakdown of the quantum Hall effect: Direct observation of inter-Landau-level tunneling
Max-Planck-Institute für Festkörperforschung
Heisenbergstr. 1, D-70569 Stuttgart, Germany
Accepted: 17 January 1999
We have measured the evolution of breakdown of the quantum Hall effect along a macroscopic constriction on a GaAs/AlGaAs 2DEG heterostructure. From the evolution of the dissipative resistivity along the drift direction, we conclude that electrons are excited to the upper Landau level at a constant rate which exponentially depends on the Hall voltage. The results are explained on the basis of impurity mediated tunneling of electrons between the Landau levels.
PACS: 73.50.Fq – High-field and nonlinear effects / 73.40.Hm – Quantum Hall effect (integer and fractional) / 72.10.Fk – Scattering by point defects, dislocations, surfaces, and other imperfections (including Kondo effect)
© EDP Sciences, 1999