Nonlinear optical response of trans-polyacetylene to the strong static electric field

The nonlinear optical response to the strong static electric field is investigated by the quantum Monte Carlo (QMC) method in the Pariser-Parr-Pople (PPP) model for trans-polyacetylene. A charge density wave (CDW) like and a charged soliton pair like charge density fluctuation induced by the electric filed are shown to provide the mechanism of the nonlinear optical response. The nonlinear optics is very sensitive to the PPP parameters and it is drastically changed by quantum fluctuations of electrons and the lattice.