Ferromagnetic resonance spectroscopy of parametric magnons excited by a four-wave process

摘要: Using a magnetic resonance force microscope, we have performed ferromagnetic spectroscopy of the parametric magnons created by four-wave process. This is achieved measuring differential response to small amplitude modulation superimposed large constant excitation power that drives dynamics uniform mode in saturation regime. By sweeping applied field, observe an abrupt readjustment total number each time coincides with mode. gives rise ultranarrow peaks whose linewidth lower than $5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ field.