Regulating magnetic skyrmions in multiferroic monolayer MnOBr.

Two-dimensional multiferroic materials that exhibit both ferroelectricity and ferromagnetism provide a new platform for the discovery and regulation of magnetic skyrmions. In this study, we utilize first-principles calculations and Monte Carlo simulations to explore the properties and regulation of magnetic skyrmions in a novel multiferroic monolayer, MnOBr. MnOBr exhibits skyrmions without the need for an external magnetic field. Upon applying an external magnetic field, we found the disappearance of labyrinth domains and the formation of a periodic arrangement of the skyrmion lattice. By employing machine learning techniques, we depict a phase diagram of MnOBr under varying magnetic fields and biaxial strain, which provides a detailed depiction of phase transitions of spin textures in monolayer MnOBr. Furthermore, in MnOBr/CdClBr heterostructures, we demonstrate that the creation and annihilation of magnetic skyrmions can be controlled by switching the polarization direction of the Janus CdClBr. These findings show potential applications of MnOBr as a 2D magnetic skyrmion material in spintronic devices.