Novel electronic structures and magnetic properties in twisted two-dimensional graphene/Janus 2H–VSeTe heterostructures

Abstract

Moiré patterns of two-dimensional (2D) van der Waals (vdW) heterostructures can induce novel electronic structures and physical properties. However, the effects of moiré pattern on magnetic properties of 2D materials are not clear yet. Herein, the electronic structures and magnetic properties of 2D graphene/Janus 2H–VSeTe (Gr/VSeTe) heterostructures with moiré patterns are investigated by density functional theory. It is found that twist angles ( θ ) can induce a band gap at Dirac cone of graphene. With further considering spin-orbit coupling and V magnetic moments of VSeTe monolayer along + z axis, valley polarization of graphene at K and K′ points appears and is found to be sensitive to the twist angle. Additionally, flat band occurs at θ = 5.2° and 10.9° due to the quasi-periodic potential induced by moiré patterns. A high spin polarization also appears in Gr/VSeTe heterostructures with certain twist angles of θ = 0°, 7.6°, 10.9° and 13.9°. Due to the changed occupation of interfacial Te- p orbitals, the magnetic anisotropy and Dzyaloshinskii-Moriya interaction of Gr/VSeTe heterostructures can be changed by twist angles. Therefore, twist angle provides a new degree of freedom for inducing the novel electronic structures and magnetic properties in the 2D magnetic vdW heterostructures. • Moiré pattern has a significant impact on the physical properties of Gr/VSeTe heterostructures. • Valley splitting is found to be sensitive to the twist angles in Gr/VSeTe heterostructures. • Flat band can be induced by twist angles at θ = 5.2° and 10.9° in Gr/VSeTe heterostructures. • Magnetic anisotropy and Dzyaloshinskii-Moriya interaction can also be tuned by twist angles.