Topological insulators based on HgTe

TL;DR

This review discusses experimental advances in 2D and 3D topological insulators based on HgTe, highlighting key findings such as nonlocal transport, high surface mobility, and the characterization of Dirac fermions.

Contribution

It compiles recent experimental results on HgTe-based topological insulators, emphasizing new observations and parameter determinations that advance understanding of their topological properties.

Findings

Observation of nonlocal ballistic and diffusion transport in 2D TIs

Record-high mobility of surface Dirac fermions in 3D TIs

Determination of TI parameters and phase of Shubnikov-de Haas oscillations

Abstract

The most interesting experimental results obtained in studies of 2D and 3D topological insulators (TIs) based on HgTe quantum wells and films are reviewed. In the case of 2D TIs, these include the observation of nonlocal ballistic and diffusion transport, the magnetic breakdown of 2D TIs, and an anomalous temperature dependence of edge-channel resistance. In 3D TIs, a record-setting high mobility of surface two-dimensional Dirac fermions (DFs) has been attained. This enabled determining all the main TI parameters (the bulk gap and the density of DFs on both of its surfaces) and provided information on the phase of the Shubnikov - de Haas oscillations of DFs, which indicates the rigid topological coupling between the fermion spin and momentum. Prospects for further research are discussed in the conclusion.