  We report on the first demonstration of generating a spin current and spin
transport in a highly doped Si channel at room temperature (RT) using a
four-terminal lateral device with a spin injector and a detector consisting of
an Fe/MgO tunnel barrier. Spin current was generated using a nonlocal
technique, and spin injection signals and Hanle-type spin precession were
successfully detected at 300 K, thus proving spin injection with the
elimination of spurious signals. The spin diffusion length and its lifetime at
RT were estimated to be 0.6 \"im and 1.3 ns by the Hanle-type spin precession,
respectively.
