What are the implications of 2D magnets for nonlinear magneto-optical (NLMO) effects? This research explores the interplay of polarization and magnetism in two-dimensional (2D) van der Waals magnets, with a focus on their remarkable tunability and its influence on NLMO effects. Through first-principles calculations, giant NLMO effects were discovered in CrI3-based 2D magnets. These effects include a dramatic shift in the polarization direction of second-harmonics generation (SHG) and the on/off switching of intensity under magnetization reversal, along with a 100% SHG circular dichroism effect. Analytical derivation showed how to achieve these giant NLMO effects and gave insight into developing general strategies in 2D magnets. The authors suggest these effects could be used for ultra-thin multifunctional optical devices as well as detecting subtle magnetic orderings. These results provide a series of intriguing NLMO phenomena, which will pave the way for basic research and also for device application of ultra-thin NLMO materials.
Published in npj Computational Materials, this study aligns with the journal's emphasis on computational methods applied to materials science. By exploring giant nonlinear magneto-optical effects in 2D magnets, the authors contribute to the understanding of these materials' optical properties and potential applications in advanced technologies.