Experimental Observation of Temperature-Driven Topological Phase Transition in HgTe/CdHgTe Quantum Wells

Maksim S Zholudev,Michal Marcinkiewicz,Nikolay N Mikhailov,Aleksandr M Kadykov,Mikhail A Fadeev,Christophe Consejo,Jeremie Torres,Sergey A Dvoretskii,Sandra Ruffenach,Wojciech Knap,Vladimir I Gavrilenko,Sergey V Morozov,Frederic Teppe

doi:10.3390/condmat4010027

Abstract

We report on the comparison between temperature-dependent magneto-absorption and magnetotransport spectroscopy of HgTe/CdHgTe quantum wells in terms of the detection of the phase transition between the topological insulator and band insulator states. Our results demonstrate that temperature-dependent magnetospectroscopy is a powerful tool to discriminate trivial and topological insulator phases, yet the magnetotransport method is shown to have advantages for the clear manifestation of the phase transition with accurate quantitative values of the transition parameter (i.e., critical magnetic field Bc).

Highlights

Due to their amazing electronic properties, 2D and 3D topological insulators (TI) have been attracting increasing attention during the last decade
When E1 and H1 levels cross each other, the band structure mimics a linear dispersion of massless Dirac fermions [3] corresponding to the phase transition between the trivial band insulator (BI) state and the TI state
Ikonnikov et al [10] have reported on magnetospectroscopy of HgTe quantum wells in CondeBnys. aMnaattleyr z2i0n19g, 4th, xe magnetotransport data at high and low temperatures Wiedmann et al [5] ha3vofe7 experimentally shown that the TI phase vanishes with temperature

Summary

Introduction

Due to their amazing electronic properties, 2D and 3D topological insulators (TI) have been attracting increasing attention during the last decade. The HgTe/CdHgTe quantum well (QW) was the first system where the TI state was predicted [1] and experimentally observed [2]. When E1 and H1 levels cross each other, the band structure mimics a linear dispersion of massless Dirac fermions [3] corresponding to the phase transition between the trivial band insulator (BI) state and the TI state.

Results

Conclusion