The effects of electric field and strain on the VCl2/WTe2 van der Waals heterojunction

Abstract Two-dimensional (2D) van der Waals (vdWs) magnetic materials provide an ideal platform for exploring long-range magnetic ordering at the 2D limit and show promising applications in next-generation spintronics devices. In this works, VCl 2 / WTe 2 vdWs heterostructures are investigated to study the electronic structure and magnetic anisotropy, as well as their modulation via external electric field and biaxial strain in the plane based on first-principles calculations. The results show that the VCl 2 / WTe 2 heterostructure is semiconducting with a band gap of 0.82 eV, a 0.4 meV valley splitting and a system magnetic anisotropy energy (MAE) of 0.033 mJ m − 2 (2.61 meV/f.u.) after taking into account of spin–orbital coupling. The application of bi-axial strain and vertical electric field to the heterostructures changes the electronic structure. A maximum MAE of −0.5 mJ m − 2 (−39.55 meV/f.u.) and a maximum valley splitting value (4.9 meV) are found for the VCl 2 / WTe 2 heterostructures at a strain of −6%. The system MAE reaches 3.2 mJ m − 2 (253 meV/f.u.) at an electric field strength of 0.3 V Å −1 , and reaches 0.96 mJ m − 2 (75.9 meV/f.u.)at −0.3 V Å −1 . It also reaches a maximum valley splitting of 3.53 meV. Under the modulation of biaxial strains and positive and negative electric fields, the VCl 2 / WTe 2 heterostructures have significant tunable electronic structure and magnetic anisotropy, which suggests that the VCl 2 /