Induced Ge Spin Polarization at the Fe/Ge Interface

We report direct experimental evidence showing induced magnetic moments on Ge at the interface in an Fe/Ge system. Details of the x-ray magnetic circular dichroism and resonant magnetic scattering at the Ge L edge demonstrate the presence of spin-polarized {it s} states at the Fermi level, as well as {it d} character moments at higher energy, which are both oriented antiparallel to the moment of the Fe layer. Use of the sum rules enables extraction of the L/S ratio, which is zero for the {it s} part and $sim0.5$ for the {it d} component. These results are consistent with layer-resolved electronic structure calculations, which estimate the {it s} and {it d} components of the Ge moment are anti-parallel to the Fe {it 3d} moment and have a magnitude of $sim0.01 mu_B$.