Spin-Induced Optical Anisotropy on van der Waals Antiferromagnet

Two-dimensional (2D) magnetic systems have received growing interest revealing new physics of magnetism in the nanoscale limit. As an important family of van der Waals magnetic materials, metal phosphorus chalcogenides have attracted intense attention due to the intrinsic antiferromagnetism and the electronic bandgap in the visible range. Recently, we observe a strong anisotropy on optical absorption in 2D antiferromagnet, nickel phosphorus trisulfides (NiPS₃), which is induced by its spin structure in the antiferromagnetic phase. The temperature and polarization dependent study indicates the strong correlation between electronic and magnetic structure. A control experiment has been conducted on the other compounds in this family, which further supports our conclusion. Our studies reveal the unique electronic and magnetic properties of NiPS₃, paving the way for potential functionalities and applications of 2D magnetic materials.