Tunable spin-valley splitting and magnetic anisotropy of two-dimensional 2H-VS2/h-VN heterostructure

Abstract

Valleytronics is proposed to explore a new approach for information storage using valley degrees of freedom. In this work, the electronic structure, spin-valley splitting and magnetic anisotropy (MA) of two-dimensional (2D) 2H-VS2/h-VN magnetic van der Waals (vdW) heterostructure are investigated systematically by first-principles calculations. The results show that the considerable spin splitting of 364.7 meV and 543.7 meV are observed at the K and K' valleys, respectively, generating an intrinsic valley splitting of 68.9 meV in the valence band for the 2H-VS2/h-VN heterostructure, which corresponds to an effective Zeeman magnetic field of 774 T based on the k·p model. The valley splitting of 2H-VS2 is well preserved in the heterostructure and can be further adjusted by altering stacking patterns, in-plane strain and interfacial distance due to the interfacial orbital hybridization. Compared with the pristine 2H-VS2 monolayer, the 2H-VS2 of heterostructure still exhibits the in-plane MA, which mainly originates from the positive contribution of the matrix element difference between the V dxy and dx2-y2 orbitals. With the increase of strain from −2% to 3%, the orientation of easy magnetization axis is transformed from in-plane to out of plane. These results suggest that the 2H-VS2/h-VN heterostructure is a potential candidate in further valleytronics and spintronics.