Optical and magnetic properties of heterostructures of magnetic 2D materials

The combination of magnetic 2D materials with distinct magnetic order in heterostructures can lead to layered materials with new magnetic properties. In this work, we study heterobilayers composed of VOCl and FeOCl monolayers, two insulating oxides with distinct magnetic order. VOCl monolayers are ferromagnetic and FeOCl monolayers are antiferromagnetic. We compute the magnetic anisotropy of the heterobilayers using density functional theory calculations including the Hubbard correction. In addition we propose a spin model to describe the first principles calculations. We have found that interlayer coupling is weak and hence the magnetic order of each monolayers is preserved in the heterobilayer. Thus, the heterobilayer combines antiferromagnetic and ferromagnetic orders. Interlayer exchange should lead both to exchange bias and to the emergence of hybrid collective modes that combine FM and AF magnons. The energy band of the heterobilayer show a type II band alignment, and feature spin-splitting of the states of the AF layer due to the breaking of the inversion symmetry.