▎ 摘　　要

Graphene/ferromagnet interface promises a plethora of new science and technology. The interfacial Dzyaloshinskii-Moriya interaction (iDMI) is essential for stabilizing chiral spin textures, which are important for future spintronic devices. Here, we report direct observation of iDMI in graphene/Ni-80 Fe-20/Ta heterostructures from nonreciprocity in spin-wave dispersion using Brillouin light-scattering technique. Linear scaling of iDMI with the inverse of Ni80Fe20 thicknesses suggests primarily interfacial origin of iDMI. Both iDMI and spinmixing conductance increase with the increase in defect density of graphene obtained by varying argon pressure during sputter deposition of Ni80Fe20. This suggests that the observed iDMI originates from defect-induced extrinsic spin-orbit coupling at the interface. The direct observation of iDMI at graphene/ferromagnet interface without perpendicular magnetic anisotropy opens a route in designing thin-film heterostructures based on two-dimensional materials for controlling chiral spin structure such as skyrmions and bubbles, and magnetic domain-wall-based storage and memory devices.