Universal Scaling of Quantum Anomalous Hall Plateau Transition

TL;DR

This paper models the critical behavior of the quantum anomalous Hall transition, predicts universal scaling laws, and confirms some predictions with experimental data.

Contribution

It introduces a microscopic model for the QAH plateau transition and maps it to a quantum percolation network model, revealing universal scaling properties.

Findings

Intermediate zero Hall conductance plateau can occur at coercive field.

Double peaks in $ ho_{xx}$ at coercivity, single peak in $ ho_{xx}$ observed.

Universal scaling laws for transport coefficients are predicted.

Abstract

We study the critical properties of the quantum anomalous Hall (QAH) plateau transition in magnetic topological insulators. We introduce a microscopic model for the plateau transition in QAH effect at the coercive field and then map it to the network model of quantum percolation in the integer quantum Hall effect plateau transition. Generally, an intermediate plateau with zero Hall conductance could occur at the coercive field. $\sigma_{xx}$ would have double peaks at the coercivity while $\rho_{xx}$ only has single peak. Remarkably, this theoretical prediction is already borne out in experiment. Universal scaling of the transport coefficients $\rho_{xy}$ and $\rho_{xx}$ are predicted.