We perform a dynamical simulation of photogenerated excitations in trans-polyacetylene by using the Su-Schrieffer-Heeger extended Hubbard model. We find that two possible excited states may be photogenerated depending on the energy gained by the system. If the system energy is higher than a critical value, soliton-antisoliton pairs are photogenerated and are free to separate, leaving behind a central breather mode. If the system energy is lower than the critical value, the soliton-antisoliton pairs will bind and form a different central oscillation: an exciton-breather. The critical energy is slightly above the soliton pair-creation energy. We discuss our results and compare with experiment.

• Received 9 April 1986

DOI:https://doi.org/10.1103/PhysRevB.34.5540