Spin Dynamics and Exchange Interactions from a Van der Waals Antiferromagnet

This talk will present our recent progress in identifying the gigahertz antiferromagnetic resonances within the easy-axis van der Waals (vdW) magnet CrSBr and understanding how their frequencies and intermode coupling can be controlled by the combination of external magnetic fields and magnetic anisotropy [1]. We have recently advanced beyond the published results [1] to achieve direct electrical detection of the resonance dynamics in few-layer CrSBr devices via their effect on tunnel magnetoresistance, and to explore the effects of externally-applied spin-orbit torque on the mode damping. We have also demonstrated that exchange bias from CrSBr acting on the van der Waals ferromagnet Fe3GeTe2 induces a spatially non-uniform spin configuration through the thickness of the Fe3GeTe2 that is not readily achievable with conventional magnetic materials, and can provide the symmetry breaking needed to enable field-free spin-orbit-torque switching in Pt/Fe3GeTe2/CrSBr heterostructures [2]. These results will be of broad interest to the magnetism and spintronics community, for researchers interested in the fundamental physics of spin order in van der Waals materials, and for those working toward making practical devices using van der Waals antiferromagnets and ferromagnets.<br/>[1] T. M. J. Cham, S. Karimeddiny, A. H. Dismukes, X. Roy, D. C. Ralph, and Y. K. Luo, Anisotropic gigahertz frequency antiferromagnetic resonance in layered van der Waals semiconductor. Nano Letters, 22, 6716-6723 (2022)<br/>[2] T. M. J. Cham, R. Dorrian, X. S. Zhang, A. H. Dismukes, D. G. Chica, X. Roy, A. F. May, D. A. Muller, D. C. Ralph, and Y. K. Luo, Exchange bias between van der Waals materials: tilted magnetic states and field-free spin-orbit-torque switching. Advanced Materials, 2305739 (2023)