Electrical creation of spin accumulation in -type germanium

We report the electrical creation of a spin accumulation in p -type Ge using an epitaxial Fe/MgO contact. The induced spin polarization was successfully detected by the Hanle effect up to 100 K, and the absence of a Schottky barrier was confirmed by measuring current–voltage characteristics. This implies that the induced spin accumulation exists in the bulk region of Ge, rather than in localized interface states. Nevertheless, we find a large magnitude of the spin accumulation, which cannot be explained with the existing diffusion model for spin injection and accumulation.