Speaker: Dirk Hennig

Abstract: We consider the propagation of electromagnetic waves through a dielectric superlattice constituted of nonlinear Kerr-type material, where the thickness of the nonlinear layer is much smaller than the layer interspacing. It is demonstrated that an increase in the amplitude of incident waves has the effect of switching from a passing to a nonpassing regime so that in the latter case the wave is completely reflected. Transmission of information in such a periodically modulated  nonlinear transmission line is then possible by simple amplitude modulation. Furthermore, we use a nonlinear Kronig-Penney model to describe electron transmission in a one-dimensional quasicrystal. Inside a layer of the corresponding superlattice model strong electron-phonon interaction induce polaronic effects giving rise to nonlinear potential terms. We show that nonlinearity, arising from strong many-body effects in the electronic propagation leads not only to multistability in the transmission but has also profound impact on the overall transparency of the quasicrystals.

NLDD05, Nonlinear excitations: theory and experiments, Sevilla, March 3-4, 2005.