Phonons in one-dimensional Peierls-Hubbard systems

Abstract
Reflectivity measurements from the ultraviolet (UV) down to the far infrared (fir) of one-dimensional mixed-valence Pt-halogen chains are discussed. Particular attention is devoted to the fir spectral range: the relevant one for the study of the phononic properties. We give evidence for the presence of such defects (polarons) along the chain axis, which are manifest in the phonon spectra through the defect modes. A lattice-vibrational calculation is further considered for the discussion of the whole phonon spectra.