Spin lifetimes and strain-controlled spin precession of drifting electrons in GaAs

We study the transport of spin-polarized electrons in n-GaAs using spatially resolved continuous-wave Faraday rotation. From the measured steady-state distribution, we determine spin relaxation times under drift conditions and, in the presence of strain, the induced spin splitting from the observed spin precession. Controlled variation of strain along [110] allows us to deduce the deformation potential causing this effect, while strain along [100] has no effect. The electric-field dependence of the spin lifetime is explained quantitatively in terms of an increase of the electron temperature.