The effect of disorder within the interaction theory of integer quantized Hall effect

TL;DR

This paper investigates how different types of disorder affect the quantized Hall effect, revealing that long-range disorder primarily determines plateau widths, contrasting with traditional single-particle models.

Contribution

It introduces a comprehensive analysis of disorder effects within the interaction theory, emphasizing the role of long-range fluctuations in quantum Hall plateau formation.

Findings

Long-range disorder potential is well screened by Thomas-Fermi screening.

Plateau widths depend mainly on long-range disorder fluctuations.

Level broadening has a negligible effect on plateau widths.

Abstract

We study effects of disorder on the integer quantized Hall effect within the screening theory, systematically. The disorder potential is analyzed considering the range of the potential fluctuations. Short range part of the single impurity potential is used to define the conductivity tensor elements within the self-consistent Born approximation, whereas the long range part is treated self-consistently at the Hartree level. Using the simple, however, fundamental Thomas-Fermi screening, we find that the long range disorder potential is well screened. While, the short range part is approximately unaffected by screening and is suitable to define the mobility at vanishing magnetic fields. In light of these range dependencies we discuss the extend of the quantized Hall plateaus considering the "mobility" of the wafer and the width of the sample, by re-formulating the Ohm's law at low temperatures and high magnetic fields. We find that, the plateau widths mainly depend on the long range fluctuations of the disorder, whereas the importance of density of states broadening is less pronounced and even is predominantly suppressed. These results are in strong contrast with the conventional single particle pictures. We show that the widths of the quantized Hall plateaus increase with increasing disorder, whereas the level broadening is negligible.