Coulomb-Engineered Magnetism in CrI₃ Monolayers

The electronic band structure and the magnetic properties of two-dimensional magnets are decisively controlled by the Coulomb interaction between carriers within the layered material. At the same time we can externally modify this interaction by means of dielectric substrates or dielectric coating. This allows for an external manipulation of internal static and dynamic magnetic properties.

Here we use a combination of the Magnetic-Force theorem and state-of-the-art ab-initio down-folding techniques to theoretically study how dielectric substrates affect the microscopic magnetic exchange interactions in monolayer CrI₃. We find that short-range exchange interactions can be drastically tuned by the environmental material, which strongly affects the magnetic transition temperature as well as the magnon excitation spectra. Based on these findings we suggest novel magnetic devices from externally spatially controlled magnetic properties.