Effect of Singwi-Tosi-Land-Sjolander local field correction on spin relaxation in n-type GaAs quantum wells at low temperature

We study the effect of the Singwi-Tosi-Land-Sjolander local field correction on spin relaxation/dephasing in n-type GaAs quantum wells at low temperature by constructing and numerically solving the kinetic spin Bloch equations. We calculate the local field factor G(q) in quantum wells by numerically solving three equations which link the local field factor, the structure factor, and the dielectric function, self-consistently. Such a correction reduces both the electron-electron Coulomb scattering and the Coulomb Hartree-Fock term. We compare the spin relaxation times with and without this correction under different conditions such as temperature, electron density, well width and spin polarization. We find that this correction leads to a decrease/increase of the spin relaxation time in the strong/weak scattering limit. At high spin polarization, it reduces the Hartree-Fock term and consequently tends to decrease the spin relaxation time. The modification of the spin relaxation time by the local field correction is more or less moderate either due to the coexistence of scattering other than the Coulomb scattering at low spin polarization and/or due to the competing effects from the Coulomb scattering and the Coulomb Hartree-Fock term at high polarization. (C) 2008 Elsevier B.V. All rights reserved.