Giant interlayer magnetic exchange interaction and charge-spin coupling in a van der Waals magnetic interface driven by p−d coupling

The van der Waals (vdW) heterostructures are a wonderful playground for condensed matter physics, and the recently discovered two-dimensional magnetism renovates this field. In this work, we construct vdW heterostructures composed of $p$- and $d$-magnetic layers, namely carbon-terminated $\mathrm{Si}\mathrm{C}(111)/\mathrm{Cr}{\mathrm{Br}}_{3}$ and hydrogenated graphene (HG)/$\mathrm{Cr}{\mathrm{Br}}_{3}$. By first-principles calculations, strong interlayer magnetic interaction is predicted, as the interlayer exchange energy is up to hundreds of meV, which may originate from the delocalization of magnetic $p$ orbitals in SiC(111) and HG. Moreover, upon transforming the interlayer magnetic order, the electronic structures of the heterostructures vary dramatically, such as the gap can change from 471 to 4 meV. This significant charge-spin coupling can be ascribed to spin-dependent $p\ensuremath{-}d$ orbital coupling across the vdW interface. The $p\ensuremath{-}d$ coupling is turned on/off by switching interlayer magnetic order, and shifts the energy level so that it alters the band gaps. Besides, the magnetic anisotropy of heterostructures also shows dependence on interlayer magnetic order. Our findings provide inspiration to design vdW heterostructures whose electronic structures can be effectively controlled by magnetism, which have potential applications in spintronics.