Many-Body Effect in Spin Dephasing in n-Type GaAs Quantum Wells

By constructing and numerically solving the kinetic Bloch equations we perform a many-body study of the spin dephasing due to the D'yakonov--Perel’ effect in n-type GaAs (100) quantum wells for high temperatures. In our study, we include the spin-conserving scattering such as the electron--phonon, the electron--nonmagnetic impurity as well as the electron--electron Coulomb scattering into consideration. The dephasing obtained from our theory contains both the single-particle and the many-body contributions with the latter originating from the inhomogeneous broadening introduced by the DP term J. Supercond.: Incorp. Novel Magn. 14(2001)245; Eur. Phys. J. B 18(2000)373. Our result agrees very well with the experimental data Phys. Rev. B 62(2000)13034 of Malinowski et al. We further show that in the case we study, the spin dephasing is dominated by the many-body effect.