We investigate the coupled magnetization dynamics in heterostructures of a single crystal of the chiral magnet $\mathrm{ Cu_2OSeO_3}$ (CSO) and a polycrystalline ferromagnet $\mathrm{ NiFe}$ (Py) thin film using broadband ferromagnetic resonance (FMR) at cryogenic temperatures. We observe the excitation of a hybrid mode (HM) below the helimagnetic transition temperature of CSO. This HM is attributed to the spin dynamics at the CSO/Py interface. We study the HM by measuring its resonance frequencies for in plane rotations of the external magnetic field. We find that the HM exhibits dominantly four-fold anisotropy, in contrast to the FMR of CSO and Py.
Categories: cond-mat.mes-hall