Event
Highly unusual magnon and exciton dynamics in two-dimensional quantum magnets is reported based on terahertz and optical spectroscopies performed on representative materials such as CrI3, NiI2, and NiPS3. By studying (anti)ferromagnetic resonance modes in the terahertz region, including their temperature and field dependences, we detected large magnetic anisotropies typical of two-dimensional quantum magnets. In contrast, a dramatic formation of Zhang-Rice excitons has been discovered in the near-infrared and visible regions in several materials. Such novel excitons are generated by a strong hybridization between the metal d- and the ligand p-orbitals. Our results also reveal an intricate connection between these excitons and the underlying magnetic order.