Room-temperature electron spin relaxation in bulk InAs

Polarization-resolved, subpicosecond pump–probe measurements at a wavelength of 3.43 μm are used to determine the electron spin relaxation time $T_1$ in bulk InAs at room temperature. The measured $T_1$ of $\text{19±4\hspace{0.05em}}\mathrm{ps}$ is in excellent agreement with the theoretical value of 21 ps, which is obtained from a nonperturbative calculation based on the D’yakonov–Perel’ mechanism of precessional spin relaxation [M. I. D’yakonov and V. I. Perel’, Sov. Phys. JETP 38, 177 (1974)].