Enhancing Perpendicular Magnetic Anisotropy in Garnet Ferrimagnet by Interfacing with Few-Layer WTe₂

Engineering magnetic anisotropy in a ferro- or ferrimagnetic (FM) thin film is crucial in a spintronic device. One way to modify the magnetic anisotropy is through the surface of the FM thin film. Here, we report the emergence of a perpendicular magnetic anisotropy (PMA) induced by interfacial interactions in a heterostructure comprised of a garnet ferrimagnet, Y₃Fe₅O₁₂ (YIG), and a low-symmetry, high spin-orbit coupling (SOC) transition metal dichalcogenide, WTe₂. At the same time, we also observed an enhancement in Gilbert damping in the WTe₂-covered YIG area. Both the magnitude of interface-induced PMA and the Gilbert damping enhancement have no observable WTe₂ thickness dependence down to a single quadruple layer, indicating that the interfacial interaction plays a critical role. The ability of WTe₂ to enhance the PMA in FM thin film, combined with its previously reported capability to generate out-of-plane damping like spin torque, makes it desirable for magnetic memory applications.