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 MnBi_2Te_4 have been critical bottlenecks to the future application of the quantum anomalous Hall effect (QAHE) at zero magnetic field. In this study, we propose a scheme to utilize capped sliding van der Waals materials to effectively modulate the magnetic and topological properties of MnBi_2Te_4. Our results demonstrate that the h-BN/MnBi_2Te_4/h-BN heterostructure, constructed by sliding ferroelectric h-BN bilayer and MnBi_2Te_4, not only realizes a transition from interlayer antiferromagnetic to ferromagnetic coupling but also significantly enhances the out-of-plane magnetism and air stability of MnBi_2Te_4. Moreover, the above magnetic properties can be further improved by tuning the interlayer distance between h-BN and MnBi_2Te_4. Additionally, the obtained band structures and topological properties clearly support that the h-BN/MnBi_2Te_4/h-BN heterostructure can harbor the QAHE 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.