Coherent Electron-Lattice Vibrations in<i>Trans</i>-Nanopolyacetylene Probed by Raman Scattering

Abstract

Unexpectedly high Raman scattering activity of carbon-carbon bond length vibrations was found in polyacetylene nanoparticles. For exciting photon energy in the transparency range of nanopolyacetylene we observed extremely high Raman scattering cross section and high intensity ratio of anti-Stokes to Stokes bands. Furthermore, the Raman activity in trans-nanopolyacetylene is characterized by intensive overtones and combinations. We present a qualitative nonlinear model of coherent weakly damped electron-lattice vibrations in ordered trans-polyacetylene chains.