Suppression of conductance fluctuation of disordered carbon nanotubes caused by thermal atomic vibration

Abstract

We have numerically succeeded in evaluating the conductance fluctuations of nitrogen-doped single-walled carbon nanotubes (N-SWCNTs), as a typical example of disordered quasi-one-dimensional materials, including the effect of thermal atomic vibration from the viewpoint of conductance histograms. We show that conductance histograms even of N-SWCNTs with over 100 nm length are described by a log-normal distribution function at tens of kelvins, which suggests that the N-SWCNTs shows localization at low temperature. On the other hand, conductance of the N-SWCNT are no longer described by a log-normal distribution function at hundreds of kelvins. Instead, the histograms are described by a Gaussian distribution function, which indicates that the N-SWCNTs definitely deviate from localization regime. In addition, we confirm that the conductance fluctuations of the N-SWCNTs are also suppressed as the temperature increases because of delocalization due to quantum decoherence caused by thermal atomic vibration.