Kink and conductance of an organic molecular wire

The effect of a kink on the conductance of a nanoscale polymer molecular wire is theoretically investigated on the basis of the Su-Schrieffer-Heeger (SSH) model combined with the Green's function formalism. It is found that, due to the appearance of kink, the molecular conductance decreases rapidly with the molecular length and reaches near zero when the molecular length is over a critical value. The reason is attributed to the localized effect of kink on the electronic state at the Fermi energy. The effect of electron-lattice coupling strength on the conductance is also discussed.