Broken sublattice symmetry induced gap opening of spin-polarized Dirac cone in MnF3

Abstract

Two-dimensional (2D) transition-metal trihalides have received extensive attention in the field of novel spintronic devices and heterostructure coupling is an effective method for achieving multifunctional integration and regulation. In this work, using first-principles calculations, we systematically study the electronic structure and magnetic properties of the 2D MnF₃/graphene heterostructures. MnF₃ monolayer exhibits Dirac half-metal properties, with electron states featuring Dirac cones in its single spin channel. With different stacking configurations, the electronic properties of both are well preserved from the band structure, interfacial charge transfer only causes the relative movement of the electronic states. Additionally, due to the broken sublattice symmetry of MnF₃ in heterostructure, a gap opening of 24.9 meV appears around the spin-polarized Dirac cone in MnF₃. Moreover, the formation of heterostructure significantly enhances the in-plane magnetic anisotropy of the MnF₃ monolayer. By reducing the interlayer distance, the spin-polarized Dirac cone has a larger gap opening of 555.5 meV, which induces the transition of MnF₃ from Dirac half-metal to magnetic semiconductor, and the Curie temperature (T_C) increases obviously. Furthermore, a spin logic device based on MnF₃/graphene heterostructures is proposed, which can complete the resistive state switching from the "1″ state to the "0″ state by application of pressure. These results provide a reference for the application of MnF₃/graphene heterostructure in spintronic devices.