Quantized Anomalous Hall Insulator in a Nanopatterned Two-Dimensional Electron Gas

TL;DR

This paper demonstrates that a quantum anomalous Hall insulator can be realized in a nanopatterned 2D electron gas with specific magnetic and spin-orbit interactions, leading to quantized Hall conductivity without Landau levels.

Contribution

It introduces a novel method to achieve QAHI in 2DEG using nanoscale patterning and magnetic fields, without relying on Landau levels.

Findings

Quantized Hall conductivity of -e^2/h in the bulk gaps

Presence of chiral edge states in finite samples

Topologically nontrivial insulating states achieved without Landau levels

Abstract

We propose that a quantum anomalous Hall insulator (QAHI) can be realized in a nanopatterned two-dimensional electron gas (2DEG) with a small in-plane magnetic field and a high carrier density. The Berry curvatures originating from the in-plane magnetic field and Rashba and Dresselhaus spin-orbit coupling, in combination with a nanoscale honeycomb lattice potential modulation, lead to topologically nontrivial insulating states in the 2DEG without Landau levels. In the bulk insulating gaps, the anomalous Hall conductivity is quantized $-e^{2}/h$, corresponding to a finite Chern number -1. There exists one gapless chiral edge state on each edge of a finite size 2DEG.