Optical Manipulation of Magnetic Phase in Bilayer CrI3

Materials that exhibit controllable antiferromagnetic-to-ferromagnetic (AFM–FM) phase transitions are of interest for next-generation data storage technologies. In this work, we investigate the potential for all-optical AFM–FM switching in bilayer CrI3 using a time-dependent Heisenberg spin model parameterized by Density Functional Theory (DFT). Our simulations demonstrate controlled magnetic phase switching from AFM to FM under sub-bandgap excitation, as well as relaxation from the AFM state to the FM ground state following above-bandgap excitation that generates a thermal spike above the Curie temperature. Moreover, both AFM and FM phases are robust against thermal noise, enabling the possibility of nonvolatile data storage. These results highlight a promising pathway toward high-speed, low-power, two-dimensional magnetic memory devices.