Abstract：Since the discovery of graphene, the family of two-dimensional (2D) materials has grown to encompass a broad range of electronic properties. However, until recently 2D crystals with intrinsic magnetism were still lacking. Such crystals would enable new ways to study 2D magnetism by harnessing the unique features of atomically-thin materials, such as electrical control for magnetoelectronics and van der Waals (vdW) engineering for novel interface phenomena. In this talk, I will describe our recent magneto-optical spectroscopy experiments on vdW magnets, chromium(III) iodide CrI3. I will discuss the layered antiferromagnetic properties of atomically-thin CrI­3 [1,2], electrical control of 2D magnetism [3], giant tunneling magnetoresistance through spin filtering effect in vdW magnetic tunnel junctions [4], and the emerging spin phenomena in vdW magnetic heterostructures [5].

Reference

[1] Bevin Huang, et. al. “Layer-dependent Ferromagnetism in a van der Waals Crystal down to the Monolayer Limit”, Nature 546, 270-273 (2017);

[2] Kyle L. Seyler, et. al. “Ligand-field helical luminescence in a 2D ferromagnetic insulator”, Nature Physics 14, 277 (2018);

[3] Bevin Huang, et. al. “Electrical Control of 2D Magnetism in Bilayer CrI3”, Nature Nanotechnology, 13, 544 (2018);

[4] Tiancheng Song, et. al. “Giant Tunneling Magnetoresistance in Spin-Filter van der Waals Heterostructures”, Science, 360, 1214 (2018);

[5] Ding Zhong, et. al. “Van der Waals engineering of ferromagnetic semiconductor heterostructures for spin and valleytronics”, Science Advances, 3, e1603113 (2017);