Interaction mediated asymmetries of the quantized Hall effect

TL;DR

This paper investigates how electron interactions and sample mobility influence the asymmetries in the integer quantum Hall effect, highlighting the role of incompressible strips and screening theory in high mobility samples.

Contribution

It provides experimental and theoretical analysis of asymmetries in the quantum Hall effect related to Coulomb interactions and screening effects in high mobility samples.

Findings

High mobility samples show shifted intersection points at even filling factors.

The asymmetry aligns with screening theory predictions considering Coulomb interactions.

The  spin-split plateau remains symmetric, explained by the effective g-model.

Abstract

Experimental and theoretical investigations on the integer quantized Hall effect in gate defined narrow Hall bars are presented. At low electron mobility the classical (high temperature) Hall resistance line RH(B) cuts through the center of all Hall plateaus. In contrast, for our high mobility samples the intersection point, at even filling factors \nu = 2; 4 ..., is clearly shifted towards larger magnetic fields B. This asymmetry is in good agreement with predictions of the screening theory, i. e. taking Coulomb interaction into account. The observed effect is directly related to the formation of incompressible strips in the Hall bar. The spin-split plateau at \nu= 1 is found to be almost symmetric regardless of the mobility. We explain this within the so-called effective g-model.