Spin relaxation near the metal-insulator transition: dominance of the   Dresselhaus spin-orbit coupling
  We identify the Dresselhaus spin-orbit coupling as the source of the dominant spin-relaxation mechanism in the impurity band of doped semiconductors. The Dresselhaus-type (i.e. allowed by bulk-inversion asymmetry) hopping terms are derived and incorporated into a tight-binding model of impurity sites, and they are shown to unexpectedly dominate the spin relaxation, leading to spin-relaxation times in good agreement with experimental values. This conclusion is drawn from two complementary approaches employed to extract the spin-relaxation time from the effective Hamiltonian: an analytical diffusive-evolution calculation and a numerical finite-size scaling. 
Guido A. Intronati, Pablo I. Tamborenea, Dietmar Weinmann, and Rodolfo   A. Jalabert
cond-mat.mes-hall