Influence of dimensionality on superconductivity in carbon nanotubes

TL;DR

This paper explores how the dimensionality and screening effects influence the transition from Luttinger liquid behavior to superconductivity in carbon nanotubes, emphasizing the role of environmental factors and electronic interactions.

Contribution

It demonstrates that screening and doping induce superconductivity in ultra-small and multi-walled carbon nanotubes, highlighting the importance of environmental dimensionality.

Findings

Superconductivity observed in ultra-small and multi-walled CNs.

Screening of Coulomb repulsion facilitates the SC phase.

Doping and environmental screening are crucial for SC emergence.

Abstract

We investigate the electronic instabilities in carbon nanotubes (CNs), looking for the break-down of the one dimensional Luttinger liquid regime due to the strong screening of the long-range part of the Coulomb repulsion. We show that such a breakdown is realized both in ultra-small single wall CNs and multi wall CNs, while a purely electronic mechanism could explain the superconductivity (SC) observed recently in ultra-small (diameter $ \sim 0.4 nm$) single wall CNs ($T_c\sim 15 ^{o}K$) and entirely end-bonded multi-walled ones ($T_c\sim 12 ^{o}K$). We show that both the doping and the screening of long-range part of the electron-electron repulsion, needed to allow the SC phase, are related to the intrinsically 3D nature of the environment where the CNs operate.