Spin-filter tunneling detection of antiferromagnetic resonance with electrically-tunable damping

Van der Waals magnets provide unique opportunities to explore magnetic phenomena and spin dynamics down to the atomically-thin limit. Additionally, when paired with other vdW materials into 2D heterostructures, they can also enable efficient spin-orbit torque driven dynamics for potential applications. Antiferromagnetic devices have the potential for much faster spin dynamics compared to ferromagnets, but measurements of resonance dynamics in intrinsic antiferromagnets have been challenging.



We will describe direct electrical detection of antiferromagnetic resonance in bilayer CrSBr samples with micron-scale areas.[1] Using a three-terminal device geometry, we measure dynamics via the tunnel magnetoresistance along the c-axis of CrSBr, sensitive to the relative orientation of the magnetic sublattices. The field dependence of the resonance frequencies differs from previous measurements of bulk CrSBr,[2] corresponding to reduced exchange in the bilayer. Our device geometry also enables electrical control of antiferromagnetic resonance using spin-orbit torque from a PtTe₂ electrode to tune the magnetic damping. We find that the spin-orbit torque is highly local - it acts only on the spin sublattice immediately adjacent to the source electrode, selectively addressing just one spin sublattice within the antiferromagnet. This localized nature allows for manipulation of individual sublattice dynamics, offering a new degree of control for layered antiferromagnets.