Ytterbium-driven strong enhancement of electron-phonon coupling in graphene

TL;DR

This study demonstrates that Ytterbium adatoms significantly enhance electron-phonon coupling in graphene, reaching the highest coupling constant observed, which could be key for inducing superconductivity.

Contribution

The paper reveals that Yb adatoms cause a tenfold increase in electron-phonon coupling in graphene, a novel finding with implications for superconductivity.

Findings

Electron-phonon coupling constant increased by up to 10 times.

Yb adatoms cause charge transfer and hybridization with graphene π bands.

The measured coupling constant is the highest for graphene to date.

Abstract

We present high-resolution angle-resolved photoemission spectroscopy study in conjunction with first principles calculations to investigate how the interaction of electrons with phonons in graphene is modified by the presence of Yb. We find that the transferred charges from Yb to the graphene layer hybridize with the graphene $\pi$ bands, leading to a strong enhancement of the electron-phonon interaction. Specifically, the electron-phonon coupling constant is increased by as much as a factor of 10 upon the introduction of Yb with respect to as grown graphene ($\leq$0.05). The observed coupling constant constitutes the highest value ever measured for graphene and suggests that the hybridization between graphene and the adatoms might be a critical parameter in realizing superconducting graphene.