Spin accumulation created electrically in an n-type germanium channel   using Schottky tunnel contacts
  Using high-quality Fe$_{3}$Si/$n^{+}$-Ge Schottky-tunnel-barrier contacts, we study spin accumulation in an $n$-type germanium ($n$-Ge) channel. In the three- or two-terminal voltage measurements with low bias current conditions at 50 K, Hanle-effect signals are clearly detected only at a forward-biased contact. These are reliable evidence for electrical detection of the spin accumulation created in the $n$-Ge channel. The estimated spin lifetime in $n$-Ge at 50 K is one order of magnitude shorter than those in $n$-Si reported recently. The magnitude of the spin signals cannot be explained by the commonly used spin diffusion model. We discuss a possible origin of the difference between experimental data and theoretical values. 
K. Kasahara, Y. Baba, K. Yamane, Y. Ando, S. Yamada, Y. Hoshi, K.   Sawano, M. Miyao, and K. Hamaya
cond-mat.mtrl-sci cond-mat.mes-hall