Large-scale impurity potential in the quantum Hall effect for the HgTe quantum well with inverted band structure

TL;DR

This study investigates how long-range impurity potentials influence electron localization and delocalization in the quantum Hall effect within a HgTe quantum well with inverted band structure, using resistivity measurements across various temperatures and magnetic fields.

Contribution

It provides detailed analysis of the impact of remote ionized impurities on localization phenomena in the quantum Hall regime for HgTe quantum wells with inverted spectrum.

Findings

Long-range impurity potential significantly affects localization in the QH regime.

Temperature influences the width of QH plateau-plateau transitions.

Localization length divergence is governed by remote impurity potential.

Abstract

We report on the longitudinal and Hall resistivities of a HgTe quantum well with inverted energy spectrum (dQW = 20.3 nm) measured in the quantum Hall (QH) regime at magnetic fields up to 9 T and temperatures 2-50 K. The temperature dependence of the QH plateau-plateau transition (PPT) widths and of variable range hopping (VRH) conduction on the Hall plateaus are analyzed. The data are presented in a genuine scale form both for PPT regions and for VRH regime. Estimations for the degree of the carrier localization length divergence reveal a decisive role of the long-range random potential (the potential of remote ionized impurities) in the localization - delocalization processes in the QH regime for the system under study.