Optical Investigation of 2-Dimensional Antiferromagnetic Materials

Magnetism in low dimensional systems is an interesting topic for the fundamental physics, and atomically thin 2-dimensional (2D) van der Waals magnetic materials are promising candidates for novel spintronic devices. Antiferromagnetic 2D materials are particularly interesting both for fundamental physics and also for antiferromagnetism-based spintronic devices. On the other hand, it is difficult to probe the magnetism in these materials because traditional research tools such as neutron scattering cannot be employed due to the very small sample volume. Optical spectroscopy is becoming increasingly important for the study of antiferromagnetic 2-dimensional materials. Raman spectroscopy, for example, has been established as an invaluable tool to probe the magnetic transition in antiferromagnetic van der Waals materials as it has been found that the magnetic ordering sometimes correlates with the changes in the Raman spectrum, and low-energy magnons can be detected through low-frequency Raman scattering measurements. Furthermore, a novel coherent excitonic state in NiPS3 stabilized by the antiferromagnetic ordering has been discovered. In this talk, I will review recent advances in the study of 2-dimensional antiferromagnetic materials using optical spectroscopy.