Propagation of carriers in a one-dimensional quasicrystal

Abstract

We have addressed the problem of dynamical localization in a one-dimensional system with a periodic potential incommensurate with the crystal lattice under the action of a dc electric field. For the chosen potential there exists a mobility edge, that is, a critical value of the ratio between the strength of potential to the half bandwidth \ensuremath{\eta}=${\mathrm{\ensuremath{\epsilon}}}_{0}$/2V, which classifies the nature of the wave functions. We show that the effect of the field is to shift the mobility edge towards the delocalized region. We show that the field influence on localization is much stronger than that due to the disorder. It is also shown that when a resonance condition is reached the wave packet oscillates with a characteristic frequency in the terahertz range for superlattices, such an effect can be used to generate electromagnetic radiation of this frequency range.