Electron-phonon coupling in graphene antidot lattices: an indication of polaronic behavior

TL;DR

This study investigates electron-phonon interactions in graphene antidot lattices, revealing strong phonon effects that suggest polaronic behavior and impact charge transport properties.

Contribution

It introduces a model accounting for phonon-modulation of hopping integrals and quantifies electron-phonon coupling effects in graphene antidot lattices.

Findings

Strong phonon-induced renormalization of electron masses

Nonmonotonic dependence of effective mass on superlattice period

Indication of polaronic behavior in the system

Abstract

We study graphene antidot lattices -- superlattices of perforations (antidots) in a graphene sheet -- using a model that accounts for the phonon-modulation of the $\pi$-electron hopping integrals. We calculate the phonon spectra of selected antidot lattices using two different semi-empirical methods. Based on the adopted model, we quantify the nature of charge carriers in the system by computing the quasiparticle weight due to the electron-phonon interaction for an excess electron in the conduction band. We find a very strong phonon-induced renormalization, with the effective electron masses exhibiting nonmonotonic dependence on the superlattice period for a given antidot diameter. Our study provides an indication of polaronic behavior and points to the necessity of taking into account the inelastic degrees of freedom in future studies of transport in graphene antidot lattices.