One-Dimensional Transport in Polymer Nanofibers

We report our transport studies in quasi-one-dimensional (1D) conductors---helical polyacetylene fibers doped with iodine---and the data analysis for other polymer single fibers and tubes. We found that at 30 K$<$T$<$300 K, the conductance and the current-voltage characteristics follow the power law $G(T) \quad \propto T^{\alpha }$ with \textit{$\alpha $ }$\sim $ 2$:$2--7$:$2 and $I(V)\propto V^{\beta }$with \textit{$\beta \sim $ } 2--5$:$7. Both $G(T)$and$I(V)$ show the features characteristic of 1D systems such as Luttinger liquid or Wigner crystal. The relationship between our results and theories for tunneling in 1D systems is discussed.