Electronic screening and correlated superconductivity in carbon nanotubes

TL;DR

This paper presents a theoretical analysis explaining superconductivity in ultra-small and multi-walled carbon nanotubes through electronic mechanisms, emphasizing the role of screening and correlated electron interactions in achieving observed transition temperatures.

Contribution

It introduces a Luttinger liquid-based approach and Hubbard-like model to explain superconductivity in carbon nanotubes, aligning theoretical predictions with experimental transition temperatures.

Findings

Superconductivity in small and multi-walled nanotubes can be explained by electronic mechanisms.

Enhanced superconducting correlations result from strong Coulomb screening.

Calculated transition temperatures match experimental values.

Abstract

A theoretical analysis of the superconductivity observed recently in Carbon nanotubes is proposed. We argue that ultra-small (diameter $ \sim 0.4 nm$) single wall carbon nanotubes (with transition temperature $T_c\sim 15 ^{o}K$) and entirely end-bonded multi-walled ones ($T_c\sim 12 ^{o}K$) can superconduct by an electronic mechanism, basically the same in both cases. By a Luttinger liquid -like approach, one finds enhanced superconducting correlations due to the strong screening of the long-range part of the Coulomb repulsion. Based on this finding, we perform a detailed analysis on the resulting Hubbard-like model, and calculate transition temperatures of the same order of magnitude as the measured ones.