Manipulating two-dimensional magnetic states via electric field and pressure.

Topological spin configurations have been an intriguing topic due to the exotic transport properties and promising applications in spintronic devices. The discovery of two-dimensional (2D) magnetic materials such as CrI provides new platforms for manipulating magnetic structures. Here, by first-principles calculations and Monte Carlo methods, we investigated the exchange interaction and magnetic states of 2D van der Waals ferromagnetic/ferroelectric heterostructure CrI/InSe. By switching the polarization in the ferroelectric InSe layer under an electric field and changing the interlayer distance between CrI and InSe under pressure, four spin configurations, ferromagnetic states, topological domain wall skyrmions, topological bimerons, and stripe domains can be realized. These striking tunable magnetic states can be understood from the Dzyaloshinskii-Moriya interaction and single-ion anisotropy parameters being modified by switching the polarization and changing the interlayer distance. Our results of controllable topological/non-topological spin states broaden the spin phenomena and potential of spintronic applications in van der Waals heterostructures.