Electrical spin injection and accumulation in CoFe/MgO/Ge contacts at   room temperature
  We first report the all-electrical spin injection and detection in CoFe/MgO/moderately doped n-Ge contact at room temperature (RT), employing threeterminal Hanle measurements. A sizable spin signal of ~170 k{\Omega} {\mu}m^2 has been observed at RT, and the analysis using a single-step tunneling model gives a spin lifetime of ~120 ps and a spin diffusion length of ~683 nm in Ge. The observed spin signal shows asymmetric bias and temperature dependences which are strongly related to the asymmetry of the tunneling process. 
Kun-Rok Jeon, Byoung-Chul Min, Young-Hun Jo, Hun-Sung Lee, Il-Jae   Shin, Chang-Yup Park, Seung-Young Park and Sung-Chul Shin
cond-mat.mes-hall