Probing the Band Topology of Mercury Telluride through Weak Localization and Antilocalization

TL;DR

This paper investigates how weak localization and antilocalization phenomena in HgTe/CdTe quantum wells reveal information about their band topology, showing a transition from WL to WAL linked to the Berry phase and energy-dependent effects.

Contribution

It demonstrates the energy-dependent transition between WL and WAL in HgTe/CdTe quantum wells and links these effects to the underlying band topology and Berry phase signatures.

Findings

Transition from WL to WAL with increasing Fermi energy in inverted band systems

Presence of a Berry phase signature in magnetoconductance profiles

Energy-dependent WAL behavior in quantum wells with inverted band topology

Abstract

We analyze the effect of weak localization (WL) and weak antilocalization (WAL) in the electronic transport through HgTe/CdTe quantum wells. We show that for increasing Fermi energy the magnetoconductance of a diffusive system with inverted band ordering features a transition from WL to WAL and back, if spin-orbit interactions from bulk and structure inversion asymmetry can be neglected. This, and an additional splitting in the magnetoconductance profile, is a signature of the Berry phase arising for inverted band ordering and not present in heterostructures with conventional ordering. In presence of spin-orbit interaction both band topologies exhibit WAL, which is distinctly energy dependent solely for quantum wells with inverted band ordering. This can be explained by an energy-dependent decomposition of the Hamiltonian into two blocks.