Enhanced spin relaxation time due to electron-electron scattering in   semiconductors
  We present a detailed experimental and theoretical analysis of the spin dynamics of two-dimensional electron gases (2DEGs) in a series of n-doped GaAs/AlGaAs quantum wells. Picosecond-resolution polarized pump-probe reflection techniques were applied in order to study in detail the temperature-, concentration- and quantum-well-width- dependencies of the spin relaxation rate of a small photoexcited electron population. A rapid enhancement of the spin life-time with temperature up to a maximum near the Fermi temperature of the 2DEG was demonstrated experimentally. These observations are consistent with the D'yakonov-Perel' spin relaxation mechanism controlled by electron-electron collisions. The experimental results and theoretical predictions for the spin relaxation times are in good quantitative agreement. 
W.J.H. Leyland, G.H. John, R.T. Harley, M.M. Glazov, E.L. Ivchenko,   D.A. Ritchie, A.J. Shields, M. Henini