  A quantitative investigation of spin-pumping-induced spin-transport in n-GaAs
was conducted at room temperature (RT). GaAs has a non-negligible spin orbit
interaction, so that electromotive force due to the inverse spin Hall effect
(ISHE) of GaAs contributed to the electromotive force detected with a platinum
(Pt) spin detector. The electromotive force detected by the Pt spin detector
had opposite polarity to that measured with a Ni80Fe20/GaAs bilayer due to the
opposite direction of spin current flow, which demonstrates successful spin
transport in the n-GaAs channel. A two-dimensional spin-diffusion model that
considers the ISHE in the n-GaAs channel reveals an accurate spin diffusion
length of t_s = 1.09 um in n-GaAs (NSi = 4x10^16 cm-3) at RT, which is
approximately half that estimated by the conventional model.
