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

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.

Topological quantum phase transition in magnetic topological insulator upon magnetization rotation

“…Fitting of the data to the form dσ xy /d(cos θ) = AT −κ yields the exponent κ = 0.61± 0.01. The exponent is consistent with those reported in the experiments of the QH plateauplateau transitions, which ranges from 0.4 to 0.7 [32]. The agreement of κ values strongly supports that the phase transition between the QAH and trivial-insulator phases belongs to the same category as the QH plateau-plateau transitions.…”