Multiferroic coupling between magnetism, in-plane structural order, and out-of-plane polarization in heterogeneous bilayer of transition-metal dichalcogenides

Abstract

We suggest a cleverly selected pair of heterogeneous bilayers of transition-metal dichalcogenides (TMDCs) can resulted in a balanced interlayer charge transfer, which induces a delicate coupling between the out-of-plane electric polarization and the in-plane structural and magnetic degrees of freedom. We performed first-principles density functional theory calculations for the model system of Li-intercalated bilayer of VS2 and ZrO2. Two stabile phases was identified in a narrow energy window: the nonmagnetic state with a large out-of-plane polarization and the ferromagnetic state with a small reversed polarization. For the former state, the donated electrons from Li intercalant occupy mostly VS2, inducing 1T phase in the ZrO2. For the latter, the electron can be shared by both VS2 and ZrO2 layer, preserving the magnetism and stabilizing the 2H phase of ZrO2.