Conductance spectra of metallic nanotube bundles

TL;DR

This study uses first principles calculations to analyze how the electronic conductance of metallic carbon nanotube bundles varies with tube arrangement and symmetry, revealing universal suppression or orientation-dependent behavior.

Contribution

It provides a detailed symmetry-based understanding of conductance and energy dependence on tube orientation in (n,n) nanotube bundles, highlighting differences based on n's divisibility by 3.

Findings

Universal conductance suppression for non-multiple of 3 n

Orientation-sensitive conductance for multiple of 3 n

Transport properties explained by symmetry considerations

Abstract

We report a first principles analysis of electronic transport characteristics for (n,n) carbon nanotube bundles. When n is not a multiple of 3, inter-tube coupling causes universal conductance suppression near Fermi level regardless of the rotational arrangement of individual tubes. However, when n is a multiple of 3, the bundles exhibit a diversified conductance dependence on the orientation details of the constituent tubes. The total energy of the bundle is also sensitive to the orientation arrangement only when n is a multiple of 3. All the transport properties and band structures can be well understood from the symmetry consideration of whether the rotational symmetry of the individual tubes is commensurate with that of the bundle.