Quantum Anomalous Hall Effects Controlled by Chiral Domain Walls

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 temperature and large topological band gaps are proposed for realizing these phenomena. Our work thus reveals the possibility of chiral DW controllable QAH effects.

Oscillation of Dzyaloshinskii–Moriya interaction driven by weak electric fields

“…[7] Electrical control of magnetism seems to have great potential for various spintronic applications. Dzyaloshinskii-Moriya interaction (DMI), as one of the key ingredients for magnetic skyrmions and chiral domain walls (DWs), [8][9][10][11][12][13] arises from the presence of spin-orbit coupling (SOC) and inversion symmetry breaking system. Recent studies suggest that the Rashba effect, which is sensitive to the interfacial potential, can contribute to the DMI at the ferromagnet/oxide interface, thereby providing the possibility of external E-field control over DMI.…”