Fig. 2: Temperature evolution of magnon–magnon coupling and dissipative coupling.

a–d Derivative FMR absorption spectra measured at f = 12 GHz. Two resonance modes are clearly identified at T = 350 K, 150 K, and 100 K but not at 200 K. These modes occurring at low and high magnetic fields are marked as mode 1 and mode 2, respectively. e–h Resonant field \({H}_{r}\) extracted from the FMR spectra plotted against the resonant frequency f at T = 350 K, 200 K, 150 K, and 100 K, respectively. Dashed rectangular boxes in f and g highlight the magnon–magnon coupling region. i–l Frequency dependence of the resonant linewidth \(\triangle H\) extracted from the FMR spectra at T = 350 K, 200 K, 150 K, and 100 K, respectively. The solid (dashed) lines show the fitting results with (without) coherent spin pumping. Error bars represent fitting uncertainty.