Nonvolatile manipulating magnetic and topological properties in sliding h-BN capped MnBi₂Te₄

Interlayer antiferromagnetic coupling, small magnetic anisotropy, and low air stability of the intrinsic magnetic topological insulator MnBi₂Te₄ have been critical bottlenecks to the future application of the quantum anomalous Hall effect at zero magnetic field. In this study, we propose a scheme to utilize capped sliding vdW materials to effectively modulate magnetic and topological properties of MnBi₂Te₄. Our results demonstrate that the h-BN/MnBi₂Te₄/h-BN heterostructure, constructed by sliding ferroelectric h-BN bilayer and MnBi₂Te₄, not only realizes a transition from interlayer antiferromagnetic to ferromagnetic coupling, but also significantly enhances the out-of-plane magnetism and air stability of MnBi₂Te₄. Moreover, the above magnetic properties can be further improved by tuning the interlayer distance between h-BN and MnBi₂Te₄. Additionally, the obtained band structures and topological properties clearly support that h-BN/MnBi₂Te₄/h-BN heterostructure can harbor quantum anomalous Hall effect with a Chern number of C = 1. This work provides a new and nonvolatile modulation approach to achieve high-temperature and high-precision QAHE at zero magnetic field.