Prediction of large spin-valley polarization in the Janus 2H-WSSe monolayer on VN magnetic substrate

Two-dimensional heterostructures based on transition metal dichalcogenides (TMDs) exhibit broad application prospects in valleytronics due to the space-reversal symmetry breaking and strong spin-orbit coupling. In this work, the electronic structure, magnetic anisotropy and valley polarization of 2H-WSSe/VN van der Waals heterostructure under various interlayer spacings, magnetic angle and in-plane strain are investigated in detail by first-principles calculations. The stacked configuration of Se-C2-1 with most stable structure shows the largest valley polarization of 386.5meV. By adjusting the interlayer spacing of heterostructure, the largest valley polarization of 702.7meV appears in Se-C2-1 stacked configuration with interlayer spacing of 2.24 angstrom. The magnetic angle theta exhibits significant effects on valley polarization and magnetic anisotropy of 2H-WSSe/VN heterostructures. The stability and valley polarization of 2H-WSSe/VN heterostructure decrease after the in-plane biaxial strain is applied. The large and tunable valley polarization as well as magnetic anisotropy in the 2H-WSSe/VN heterostructures make it potential applications in valleytronic devices.