Bulk MnBi2Te4 (MBT) is an intrinsic antiferromagnetic topological insulator. However, its low N\'eel temperature of ∼25K severely restricts its practical applications. Here, we propose a van der Waals heterostructure composed of monolayer MBT (ML-MBT) and monolayer MnBr3, an intrinsic Chern insulator possessing a high Curie temperature (TC∼200K). By employing density functional theory calculations and Monte Carlo simulations, we demonstrate that interfacing ML-MBT with MnBr3 significantly enhances the TC of ML-MBT by a factor of four to five. Electronic correlations characterized by the Hubbard parameter U2 for Mn-d orbitals in MnBr3 play a crucial role in governing magnetic coupling within the system. At a moderate correlation strength of U2=3.0eV, slight structural distortions in MnBr3 break intralayer symmetry, enabling robust interlayer ferromagnetic coupling and yielding a single, unified magnetic transition. Increasing U2 reduces these structural distortions, weakens interlayer coupling, and induces two distinct magnetic transitions, indicating interlayer magnetic decoupling. Thus, the MBT/MnBr3 heterostructure offers a novel approach for controlling magnetic order and enhancing the performance of spintronic devices.
@article{arxiv.2506.13448,
title = {Electronic Correlations Control Interlayer Coupling and Magnetic Transition in MnBi$_2$Te$_4$/MnBr$_3$ Heterostructure},
author = {Yuanhao Zhu and Xixi Yuan and Ying Zhao and Jin Zhang and Zijing Ding and Huixia Fu},
journal= {arXiv preprint arXiv:2506.13448},
year = {2025}
}