This paper investigates giant nonlinear magneto-optical (NLMO) effects in CrI₃-based 2D magnets using first-principles calculations. The study reveals a dramatic change in second-harmonics generation (SHG) polarization direction and intensity under magnetization reversal, along with a 100% SHG circular dichroism effect. These findings suggest potential applications in ultra-thin multifunctional optical devices and subtle magnetic ordering detection. The authors analytically derive conditions for giant NLMO effects and propose general strategies for realizing them in 2D magnets.

Dezhao Wu, Meng Ye, Haowei Chen, Yong Xu, Wenhui Duan