Quantum anomalous Hall effects controlled by chiral domain walls

TL;DR

This paper demonstrates how magnetic chiral domain walls can control and reconfigure the quantum anomalous Hall effect, enabling tunable topological states in two-dimensional magnetic materials.

Contribution

It introduces a method to manipulate the quantum anomalous Hall effect via chiral domain walls driven by DMI, magnetic fields, thermal fluctuations, and spin currents.

Findings

Chiral domain walls can divide a material into zones with opposite Hall conductance.

External magnetic fields and thermal fluctuations can reconfigure the QAH effect.

Spin currents can move chiral domain walls, tuning the position of chiral edge states.

Abstract

We report the interplay between two different topological phases in condensed matter physics, the magnetic chiral domain wall (DW), and the quantum anomalous Hall (QAH) effect. We show that the chiral DW driven by Dzyaloshinskii-Moriya interaction (DMI) can divide the uniform domain into several zones where the neighboring zone possesses opposite quantized Hall conductance. The separated domain with a chiral edge state (CES) can be continuously modified by external magnetic field-induced domain expansion and thermal fluctuation, which gives rise to the reconfigurable QAH effect. More interestingly, we show that the position of CES can be tuned by spin current-driven chiral DW motion. Several two-dimensional magnets with high Curie temperatures and large topological band gaps are proposed for realizing these phenomena. Our work thus reveals the possibility of chiral DW controllable QAH effects.