Generic Approach to Intrinsic Magnetic Second-Order Topological Insulators via Inverted <i>p</i>–<i>d</i> Orbitals

The integration of intrinsically magnetic and topologically nontrivial two-dimensional materials holds tantalizing prospects for exotic quantum anomalous Hall insulators and magnetic second-order topological insulators (SOTIs). Compared with their well-studied nonmagnetic counterparts, the pursuit of intrinsic magnetic SOTIs remains limited. In this work, we address this gap by focusing on <i>p</i>-<i>d</i> orbitals inversion, a fundamental but often overlooked phenomena in the construction of topological materials. We begin by developing a theoretical framework to elucidate <i>p</i>-<i>d</i> orbital inversion through a combined density-functional theory calculation and Wannier downfolding. Subsequently we showcase the generality of this concept in realizing ferromagnetism SOTIs by identifying two real materials with distinct lattices: 1<i>T</i>-VS₂ monolayer in a hexagonal lattice and CrAs monolayer in a square lattice. We further compare it with other mechanisms requiring spin-orbit coupling and explore the similarities to topological Kondo insulators. Our findings establish a generic pathway toward intrinsic magnetic SOTIs.