Electron-phonon coupling in the C60 fullerene within the many-body GW approach

TL;DR

This paper uses the GW many-body approach to accurately calculate electron-phonon coupling in C60 fullerene, revealing significant enhancements over standard DFT and aligning well with experimental data, impacting future studies of covalent systems.

Contribution

It demonstrates that GW calculations significantly improve the accuracy of electron-phonon coupling estimates in C60 compared to standard DFT methods.

Findings

GW approach increases electron-phonon coupling strength by 48%.

Calculated coupling values agree within 4% of experimental data.

Results suggest reevaluating DFT-based electron-phonon calculations in covalent systems.

Abstract

We study the electron-phonon coupling in the C60 fullerene within the first-principles GW approach, focusing on the lowest unoccupied t1u three-fold electronic state which is relevant for the superconducting transition in electron doped fullerides. It is shown that the strength of the coupling is significantly enhanced as compared to standard density functional theory calculations with (semi)local functionals, with a 48% increase of the electron-phonon potential Vep. The calculated GW value for the contribution from the Hg modes of 93 meV comes within 4% of the most recent experimental values. The present results call for a reinvestigation of previous density functional based calculations of electron-phonon coupling in covalent systems in general.