Dzhioev R I, Kavokin K V, Korenev V L, Lazarev M V, Poletaev N K, Zakharchenya B P, Stinaff E A, Gammon D, Bracker A S, Ware M E
A. F. Ioffe Physical Technical Institute, St. Petersburg, 194021, Russia.
Phys Rev Lett. 2004 Nov 19;93(21):216402. doi: 10.1103/PhysRevLett.93.216402. Epub 2004 Nov 15.
We report a large and unexpected suppression of the free electron spin-relaxation in lightly doped n-GaAs bulk crystals. The spin-relaxation rate shows a weak mobility dependence and saturates at a level 30 times less than that predicted by the Dyakonov-Perel theory. The dynamics of the spin-orbit field differs substantially from the usual scheme: although all the experimental data can be self-consistently interpreted as a precessional spin-relaxation induced by a random spin-orbit field, the correlation time of this random field, surprisingly, is much shorter than, and is independent of, the momentum relaxation time determined from transport measurements.
