Coulomb gaps in one-dimensional spin-polarized electron systems

Soliton fractional charge of disordered graphene nanoribbon

We investigate the properties of the gap-edge states of half-filled interacting disordered zigzag graphene nanoribbons, and find that the midgap states can display a quantized fractional charge of 1/2. These gap-edge states can be represented by topological kinks with their site probability distribution divided between the left and right zigzag edges with different chiralities. In addition, there are numerous spin-split gap-edge states, similar to those in a Mott-Anderson insulator.

Bias dependent crossover from variable range hopping to power law characteristics in the resistivity of polymer nanowires

The electronic transport properties of ultra-low doped conducting polymer nanowires exhibit characteristics of a pinned one-dimensional Wigner crystal (1D WC) due to the long range electron-electron interaction at low temperature (<30 K). These wires also show characteristics of three-dimensional variable range hopping (3D VRH) at higher temperature. Here we report a resistivity study of these nanowires as a function of the bias around and above 30 K, to show that a crossover takes place from 3D VRH to power law behavior as the bias voltage or current is increased from a low to a relatively high value. The experimental results for this temperature range show several similarities to the theoretically predicted properties of disordered Lüttinger liquid, though at lower temperature the characteristics of the 1D WC are obtained for these nanowires.

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) proportional, Talpha with alpha approximately 2.2-7.2 and I(V) proportional, Vbeta with beta approximately 2-5.7. Both G(T) andI(V) show the features characteristic of 1D systems such as a Luttinger liquid or Wigner crystal. The relationship between our results and theories for tunneling in 1D systems is discussed.