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

TL;DR

This paper investigates how edge channel-related non-local behavior persists in wide parabolic quantum wells of PbTe even after the quantum Hall effect is quenched, revealing conductance fluctuations due to edge channel backscattering.

Contribution

It demonstrates that in multi-valley semiconductors, edge channel effects can continue beyond the quantum Hall regime, leading to conductance fluctuations caused by backscattering.

Findings

Quantum Hall effect is quenched in wide PbTe quantum wells.

Edge channel-related non-local behavior persists in the 3D regime.

Conductance fluctuations arise from edge channel backscattering.

Abstract

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