Strong Dzyaloshinskii-Moriya interaction in two-dimensional magnets via lithium absorption

Dzyaloshinskii-Moriya interaction (DMI) is of particular interest as it plays a primary role in stabilizing topological chiral magnetism such as skyrmions and has been intensively studied due to its potential applications for next-generation information storage technologies. For two-dimensional (2D) magnets, although Janus structure offers a paradigm to realize strong DMI, further studies are confined by the strict fabrication and the necessity of heavy atoms. Here, using first-principles calculations, we propose a strategy beyond this limit, where Li atoms are absorbed on the surface of a 2D magnet, resulting in a strong DMI through the Rashba effect by introducing an effective electric field generated by the perpendicular electronic polarization due to the charge transfer after the absorption. Furthermore, taking ${\mathrm{MnSe}}_{2}$ monolayer as an example, we predict the various phase transitions of skyrmions under strain manipulations and external magnetic fields. Our findings pave a road toward obtaining topological chiral magnetism.