Intrinsic inhomogeneity due to nonlinearity

Abstract

Presence of strong nonlinearity in a material, either explicit, or effective (resulting from the interaction of coupled degrees of freedom), can lead to intrinsic inhomogeneity even in a periodic extended system. We briefly discuss two examples where such a breaking of the translational symmetry due to nonlinearity (i) determines the optical features (in particular the resonance Raman scattering spectra) of a quasi-one-dimensional halogen-bridged mixed-valence transition metal complex, and (ii) enhances the trapping of a charge in a model of DNA, which is likely to affect the long-range transport properties in this biomolecule.