Lattice Relaxation of Photo-Excited States in Conjugated Polymers

Polyacetylene is a prototypical conjugated polymer which exhibits lattice dimerization and which supports solitons (kinks in the dimerization pattern). We have carried out a theoretical study of the lattice relaxation of some low-lying excited states in polyacetylene. Degenerate perturbation, strong coupling and density matrix renormalization group methods are employed for the calculations. Based on the results of those calculations, we discuss the relaxation of the major low-lying photoexcited states into solitons in their various spin and charge states.