Raman spectroscopic evidence for superconductivity at 645 K in single-walled carbon nanotubes

TL;DR

This study presents Raman spectroscopic evidence suggesting high-temperature superconductivity at 645 K in single-walled carbon nanotubes, supported by magnetic pair-breaking effects and consistent with electrical and tunneling data.

Contribution

It provides the first spectroscopic evidence for superconductivity at 645 K in carbon nanotubes, proposing a mechanism involving acoustic plasmons in a quasi-one-dimensional system.

Findings

Raman G-band frequency shifts indicate superconductivity at 645 K.

Magnetic pair-breaking effects explain the Raman data.

Consistent with electrical transport and tunneling measurements.

Abstract

The temperature dependent frequency shifts of the Raman active G-band have recently been measured by R.Walter et al. for single-walled carbon nanotubes containing different concentrations of the magnetic impurity Ni:Co. These Raman data can be quantitatively explained by magnetic pair-breaking effect on a superconductor with a mean-field transition temperature T_c0 of 645 K, in excellent agreement with independent electrical transport and single-particle tunneling data. We suggest that such high-T_c superconductivity might arise from the pairing interaction mediated mainly by undamped acoustic plasmons in a quasi-one-dimensional electronic system.