Spin relaxation of electrons in p-doped GaAs quantum wells under applied voltage

The spin-relaxation times of the electrons excited in p-doped quantum wells are calculated with the spin-flip mechanism being the exchange interaction between the excited electrons and the Fermi sea of holes. The spin mixing of the valence-hole states is included in the calculation. On one hand, this mixing enhances the spin-flip scattering due to an increase of the hole density of states. On the other hand, the exchange loses strength, resulting in spin-relaxation times similar to the ones calculated when neglecting valence spin mixing. The effects of an applied gate voltage to the system are also investigated, since it varies the exchange strength, by breaking the mirror symmetry of the potential, and changes the hole concentration in the well. (C) 1997 American Institute of Physics.