Effect of Magnetic Tuning and Induced Charge Transfer Isotropy in a CrI3-Based 2D Trilayer Heterostructure

We predict the induction/suppression of Chern insulating states in graphene and semiconductor to metal phase transition in MoS2under the influence of magnetic tuning of CrI3from a ferromagnetic (FM) case to an antiferromagnetic (AFM) one. We examine the spin-dependent electronic structure of the trilayer constructed with a 2D magnetic insulator (CrI3) sandwiched between graphene and MoS2using first principle calculations. We observe that the induced σzlattice strain breaks the symmetry of graphene's Dirac cone (which shows a bandgap of ∼0.47 eV), and the interlayer charge transfer results in a metallic trilayer. In the ferromagnetic case, for the spin-down channel, the Dirac cone split lies in the bandgap of CrI3, inducing Chern insulating states of graphene. As we switch to an antiferromagnetic case, graphene loses its Chern insulating states and hybridizes with the substrate in both of the spin channels. When spin-orbit coupling interactions are considered, the Dirac cone split of graphene is preserved which now lies in the bandgap of CrI3, enhancing its Chern insulating properties. Hexagonal MoS2however shows a semiconductor to metal transition in both the FM and the AFM cases which we believe has not been reported previously. Under the effect of spin-orbit coupling, the valence bands of MoS2shift above the Fermi level, retaining the semiconductor to metal transition. The effects examined in this work could lead to the design of CrI3-based 2D MOS-like devices with potential applications in ultrathin supercapacitors and quantum transistors.