Abstract
<p>We have used time-resolved spectroscopy to measure the relaxation of spin polarizations in the narrow gap semiconductor material <i>n</i>-InAs as a function of temperature, doping, and pump wavelength. The results are consistent with the D'Yakonov-Perel mechanism for temperatures between 77 and 300 K. However, the data suggest that electron-electron scattering should be taken into account in determining the dependence of the spin lifetime on the carrier concentration in the range 5.2×10<sup>16–</sup>8.8×10<sup>17</sup> cm<sup>–3</sup>. For a sample with doping of 1.22×10<sup>17</sup> cm<sup>–3</sup> the spin lifetime was 24 ps at room temperature. By applying a magnetic field in the sample plane we also observed coherent precession of the spins in the time domain, with a <i>g>/i> factor <i>g</i><sup>*</sup>=–13, also at room temperature.</p>