Current-induced asymmetries of incompressible strips in narrow quantum Hall systems

Abstract

First, we present recent experimental results confirming previously predicted strong asymmetries of the current distribution in narrow Hall bars under conditions of the integer quantum Hall effect (IQHE). Then, using a previously developed self-consistent screening and transport theory of the IQHE, we investigate how these asymmetries, which are due to a nonlinear feedback effect of the imposed current on the electron distribution in the sample, depend on relevant parameters, such as strength of the imposed current, magnetic field, temperature and collision broadening of the Landau-quantized energy bands. We find that many aspects of the experimental results can be understood within this approach, whereas other aspects require explicit consideration of additional mechanisms, which may lead to the breakdown of the IQHE.