Substrate induced electronic phase transitions of CrI 3 based van der Waals heterostructures

We perform first principle density functional theory calculations to predict the substrate induced electronic phase transitions of CrI3 based 2-D heterostructures. We adsorb graphene and MoS2 on novel 2-D ferromagnetic semiconductor—CrI3 and investigate the electronic and magnetic properties of these heterostructures with and without spin orbit coupling (SOC). We find that when strained MoS2 is adsorbed on CrI3, the spin dependent band gap which is a characteristic of CrI3, ceases to remain. The bandgap of the heterostructure reduces drastically (∼ 70%) and the heterostructure shows an indirect, spin-independent bandgap of ∼ 0.5 eV. The heterostructure remains magnetic (with and without SOC) with the magnetic moment localized primarily on CrI3. Adsorption of graphene on CrI3 induces an electronic phase transition of the subsequent heterostructure to a ferromagnetic metal in both the spin configurations with magnetic moment localized on CrI3. The SOC induced interaction opens a bandgap of ∼ 30 meV in the Dirac cone of graphene, which allows us to visualize Chern insulating states without reducing van der Waals gap.