Experiment study on special anisotropy of spin mixing conductance

Spin pumping, a promising technique for generating pure spin current via ferromagnetic resonance (FMR), can pump nonequilibrium magnetization through the interface between normal metal (NM) and ferromagnetic metal or ferromagnetic insulator. The efficiency of spin current injection is determined by spin mixing conductance (SMC). In this work, we systematically investigate the values of the SMC in NM(Pt, Pd, W, Mo)/YIG systems. By using cavity FMR, we found that the SMC has in-plane isotropy but out-of-plane anisotropy. The values of SMC show maximum when magnetization is along film normal. We also used electrical detection of invers spin hall voltage to double check the anisotropy of SMC. We attribute such anisotropy to the interfacial spin orbit coupling.