Interaction induced edge states in HgTe/CdTe Quantum Well under magnetic field

TL;DR

This study investigates how Hubbard-type interactions and bulk inversion asymmetry influence edge states in doped HgTe/CdTe quantum wells under magnetic fields, revealing interaction-enhanced effects that explain experimental edge conductance.

Contribution

It demonstrates that interactions significantly enhance bulk inversion asymmetry, leading to edge-like states in doped HgTe/CdTe quantum wells under magnetic fields, a novel insight into topological insulator behavior.

Findings

Interaction enhances bulk inversion asymmetry near band inversion destruction.

Enhanced BIA creates edge-like electronic states.

Explains experimental edge conductance in doped HgTe/CdTe quantum wells.

Abstract

In this paper, we study doped HgTe/CdTe quantum well with Hubbard-type interaction under perpendicular magnetic field using a lattice Bernevig-Hughes-Zhang (BHZ) model with a bulk inversion asymmetry (BIA) term. We show that the BIA term is strongly enhanced by interaction around the region when the band inversion of the topological insulator is destroyed by a magnetic field. The enhanced BIA term creates edge-like electronic states which can explain the experimentally discovered edge conductance in doped HgTe/CdTe quantum well at similar magnetic field regime.