Rabi Oscillations in Realistic Superlattice with Finite Bloch Bands

We investigate the dynamical processes taking place in nanodevices by high-frequency dc-ac fields. We found that Rabi oscillations between minibands are clearly identified under theoretical resonant conditions derived by an ideal two bands superlattice model, the resonant conditions have broadened, and the amount of broadening is about four times of the Rabi oscillation frequency. We also want to elucidate the role of different mechanisms that could lead to loss of quantum coherence. Our results show how the dephasing effects of disorder of interface roughness and doping fluctuation that destroy after some periods coherent oscillations, such as Rabi oscillations, can be reduced dramatically if we apply a bias static electric field to the superlattice system. Doping fluctuation's dephasing effect is much stronger than that of interface roughness in coherent process of realistic superlattices.