Spin relaxation in cubic III-V semiconductors via interaction with polar optical phonons

Spin-relaxation rates have been calculated for the Elliott-Yafet (EY) and D'yakonov-Perel (DP) mechanisms involving the interaction with polar-optical phonons. The inelastic nature of the collisions have been fully taken into account and expressions for the energy-dependent time constants have been found for arbitrary degeneracy and for both strong and weak spin-population differences. The ladder technique, commonly used for solving the Boltzmann equation, has been employed in the case of the DP mechanism. We investigate the energy and temperature dependence of both mechanisms and compare their spin-relaxation rates. We find that the EY mechanism is considerably weaker than the DP mechanism in the temperature range where polar-optical-phonon scattering is expected to be significant. The DP spin-relaxation time is found to exhibit a nonmonotonic temperature dependence and the origin of this is discussed.