Coulomb-blockade transport in quasi-one dimensional polymer nanofibers

TL;DR

This study investigates low-temperature electron transport in quasi-one-dimensional polymer nanofibers, revealing Coulomb blockade effects and a transition to Luttinger liquid behavior at higher temperatures.

Contribution

It provides experimental evidence of Coulomb blockade and Luttinger liquid crossover in doped polymer nanofibers, highlighting their potential as nanoscale electronic components.

Findings

Threshold voltage observed below 30-40 K

Current scales as (V/Vt - 1)^zeta with zeta ~ 2

Differential conductance oscillations increase below 10 K

Abstract

We report the low temperature current-voltage (I-V) characteristics studies in quasi-one dimensional conducting polymer nanofibers. We find a threshold voltage Vt below which little current flows at temperatures below 30-40 K. For V > Vt current scales as (V/Vt - 1)^zeta, where zeta ~ 1.8-2.1 at high biases. Differential conductance oscillations are found whose magnitude increases as temperature decreases below 10 K. We attribute the observed low temperature I-V behavior to Coulomb blockade effects with a crossover to Luttinger liquid-like behavior at high temperature. We demonstrate that at low temperatures such a doped conjugated polymer fiber can be considered as an array of small conducting regions separated by nanoscale barriers, where the Coulomb blockade tunneling is the dominant transport mechanism.