Muons for spintronics: Photo-induced conduction electron polarization in n-type GaAs observed by the muonium method

Abstract The spin-dependent exchange scattering between the muonium (Mu) electron and polarized conduction electrons excited by circularly polarized 831 nm laser light was observed in n-type GaAs with 3.6×10 16  cm −3 Si doping at low temperature by measuring a change in the polarization of Mu against the conduction electron polarization (CEP) direction. Correct signal response was confirmed with respect to the laser power. These results are encouraging for the Mu technique to be applied to probe CEP in various spintronics material systems.