Quantum anomalous Hall insulator state in ferromagnetically ordered <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>Mn</mml:mi><mml:msub><mml:mi>Bi</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Te</mml:mi><mml:mn>4</mml:mn></mml:msub><mml:mo>/</mml:mo><mml:mi mathvariant="normal">V</mml:mi><mml:msub><mml:mi>Bi</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Te</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math> heterostructures
Wenxuan Zhu, Cheng Song, Liyang Liao, Zhi‐Yuan Zhou, Hua Bai, Yongjian Zhou, Feng Pan
Abstract
The quantum anomalous Hall effect (QAHE) has been experimentally realized in the van der Waals layered topological insulator $\mathrm{Mn}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}$. However, the antiferromagnetic order of $\mathrm{Mn}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}$ restricts the experimental observation of the QAHE at zero magnetic field. Based on first-principle calculations, we find that stacking $\mathrm{Mn}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}$ with $\mathrm{V}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}$, another material from the $\mathrm{M}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}$ family, can realize a ferromagnetic coupling between layers with an out-of-plane easy axis. The nontrivial topological phase exists in $\mathrm{Mn}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}/\mathrm{V}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}$ bilayers and multilayers. $\mathrm{Mn}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}$ is the main source of QAHE, while $\mathrm{V}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}$ boosts ferromagnetic coupling between the layers. Thus QAHE can be achieved at zero magnetic field in $\mathrm{Mn}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}/\mathrm{V}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}$ heterostructures, irrespective of odd and even layers. Our finding sheds light on strongly pursuing robust QAHE in van der Waals magnetic topological insulators.