NONLINEAR EXCITATIONS DYNAMICS IN MOLECULAR SWITCHES

The charge transfer on a single polyacetylene chain is studied with im purities and added molecules working as switches. The chain is modeled by a Su-Schrieffer-Heeger (SSH) type Hamiltonian extended to include the effects of an external field and the parameters of the switching: molecules. Tile equations of motion of the system are numerically inte grated and the time evolution of the charge on the chain is analyzed. The charge transfer through the sites that work like a switch is consi dered. Two basic types of molecular switches are studied: pair of dono r-acceptor molecules embedded in tile polymer chain and bonded to the chain. The main differences between these two models of switches are d etermined. The influence of the parameters of the molecules (site ener gy and bond strengh) on the charge transfer as well as the changes the y must undergo to characterize the molecular switch is determined. The role of the length of separation between the sites where the donor an d acceptor molecules bond is clarified.