EFFECT OF A FLUCTUATING ELECTRIC FIELD ON ELECTRON SPIN DEPHASING TIME IN III–V SEMICONDUCTORS

We investigate the electron spin dephasing in low n-doped GaAs semiconductorbulks driven by a correlated fluctuating electric field. The electrondynamics is simulated by a Monte Carlo procedure which keeps intoaccount all the possible scattering phenomena of the hot electrons in themedium and includes the evolution of spin polarization. Spin relaxationtimes are computed through the D’yakonov–Perel process, which is theonly relevant relaxation mechanism in zinc-blende semiconductors. Thedecay of initial spin polarization of conduction electrons is calculated fordifferent values of field strength, noise intensity and noise correlation time.For values of noise correlation time comparable to the spin lifetime of thesystem, we find that spin relaxation times are significantly affected by theexternal noise. The effect increases with the noise amplitude. Moreover,for each value of the noise amplitude, a nonmonotonic behaviour of spinrelaxation time as a function of the noise correlation time is found.