Quenching of the Quantum Hall Effect in PbTe Wide Parabolic Quantum Wells

We show that for the case of a many valley host semiconductor an edge channel (EC) related non-local behaviour can persist also in the 3D-regime where the quantum Hall effect (QHE) is already quenched. We demonstrate that the QHE is replaced by conductance fluctuations due to EC backscattering in the contact arms, which leads to a fluctuating current redistribution between a dissipative bulk electron system and a less-dissipative EC-system. Both electron systems are located in different valleys of the band structure. The linear increase of Rxx with the magnetic field is explained by EC-backscattering in the Hall bar