Spin excitation and manipulation with 2D magnet/semiconductor heterostructure

The advent of two-dimensional (2D) magnetic crystals has enabled both the study of fundamental magnetic interactions in reduced dimensions and novel spin manipulation approaches for spintronics. When combined with other 2D materials, their interlayer interactions can open up new optical and electrical pathways for controlling and reading out the spin states. In particular, a monolayer semiconducting transition metal dichalcogenide (TMD) has coupled valley and spin degrees of freedom, where the valley- and spin-polarized carriers can be selectively excited through a valley-dependent optical selection rule. In this talk, I will present our recent works on the spin excitations and manipulation driven by the interlayer interactions in the heterostructures of 2D magnets and semiconducting TMD layers, mainly focusing on magneto-optical measurements in antiferromagnetic heterostructures including CrI₃ and CrSBr. With interlayer charge transfer, we showed that coherent spin waves in 2D magnet can be launched via ultrafast exciton excitation in the TMD. Furthermore, the spin-dependent charge transfer and tunneling effects across the interface provide on-demand control of the spin and valley indexes, which can effectively tune the light emission properties.