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 semiconductor bulks driven by a correlated fluctuating electric field. The electron dynamics is simulated by a Monte Carlo procedure which keeps into account all the possible scattering phenomena of the hot electrons in the medium and includes the evolution of spin polarization. Spin relaxation times are computed through the D’yakonov–Perel process, which is the only relevant relaxation mechanism in zinc-blende semiconductors. The decay of initial spin polarization of conduction electrons is calculated for different values of field strength, noise intensity and noise correlation time. For values of noise correlation time comparable to the spin lifetime of the system, we find that spin relaxation times are significantly affected by the external noise. The effect increases with the noise amplitude. Moreover, for each value of the noise amplitude, a nonmonotonic behaviour of spin relaxation time as a function of the noise correlation time is found.