Substrate effect on the electronic band structure and topological properties in a monolayer V₂O₃ magnetic topological...

Monolayer V₂O₃, a two-dimensional magnetic topological insulator with intrinsic ferromagnetic order and a nontrivial band gap, offers a promising platform for realizing quantum anomalous Hall (QAH) states. Using first-principles density functional theory calculations, we systematically investigate the impact of substrate selection on its electronic and topological properties, focusing on substrate engineering and aiming to understand how different substrates modify the electronic structure and topological phases of V₂O₃ monolayers. By modeling heterostructures with van der Waals (vdW) substrates, we demonstrate that non-magnetic substrates such as h-BN preserve the QAH phase with a Chern number C = 1, maintaining gapless chiral edge states. In contrast, ferromagnetic substrates introduce additional magnetic exchange fields and interfacial charge transfer, which significantly perturb the electronic structure of V₂O₃ and shift the Fermi level, thereby destroying the QAH state. These findings establish substrate engineering as a pivotal strategy for experimental realization of dissipationless edge transport in V₂O₃-based vdW heterostructures, advancing their potential applications as low-power topological electronics.