Evidence for the Presence of Spin Accumulation in Localized States at   Ferromagnet-Silicon Interfaces
  We experimentally show evidence for the presence of spin accumulation in localized states at ferromagnet-silicon interfaces, detected by electrical Hanle effect measurements in CoFe/$n^{+}$-Si/$n$-Si lateral devices. By controlling the measurement temperature, we can clearly observe marked changes in the spin-accumulation signals at low temperatures, at which the electron transport across the interface changes from the direct tunneling to the two-step one via the localized states. We discuss in detail the difference in the spin accumulation between in the Si channel and in the localized states. 
Y. Ando, S. Yamada, K. Kasahara, K. Masaki, K. Sawano, M. Miyao, and   K. Hamaya
cond-mat.mtrl-sci cond-mat.mes-hall