Fig. 1: Magnon resonances and temperature modulation.
From: Resonant thermal energy transfer to magnons in a ferromagnetic nanolayer
a Fast Fourier transform spectra showing the fundamental magnon mode for several values of magnetic field, B (left panel) and the field dependence of its frequency, f (right panel) for the 5-nm-thick Fe0.81Ga0.19 energy-harvesting layer. Symbols show f(B) obtained by fast Fourier transformation of Kerr rotation signals measured in a single pulse pump–probe experiment. Solid lines are calculated dependences for ΔT = 0 K (upper curve) and ΔT = 200 K (lower curve). The dashed horizontal lines show the frequencies of the harmonics in the temperature modulation spectrum induced by the 10 GHz optical excitation. The vertical arrows indicate the expected resonances for the fundamental magnon mode at these harmonics. b Scheme of the experiment. c Calculated temporal evolution of the Fe0.81Ga0.19 lattice temperature induced by the 10 GHz optical excitation of the Fe0.81Ga0.19/GaAs heterostructure at the pump excitation power W = 95 mW (upper panel) and its Fourier spectrum (lower panel).
