Incoherent Spin Pumping From Yig Single Crystals

Ferromagnetic resonance (FMR) in yttrium iron garnet (YIG)/Pt with a suitable YIG thickness in the submillimeter range show pure spin current contributions from the uniform FMR (UFMR) mode and various spin-wave resonance (SWR) modes, each with a different absorption intensity, inverse spin Hall voltage, and temperature dependence. The higher order mode of SWR with nonzero moment transferring along the thickness direction induces a maximum dc voltage among all modes. The spin current driven by UFMR and SWR has a linear T and power-law T dependence, respectively. In addition, the mixing conductance is derived for both modes, indicative of power-law T dependences. There is an absence of evidence for coherent spin pumping in YIG/Pt.