Velocity Renormalization and Carrier Lifetime in Graphene from Electron-Phonon Interaction

TL;DR

This study uses first-principles calculations to analyze how electron-phonon interactions affect velocity renormalization and carrier lifetime in graphene, revealing a doping-dependent velocity reduction and consistency with photoemission data.

Contribution

It provides a detailed first-principles analysis of electron self-energy in graphene, highlighting the impact of phonons on electronic properties and band velocity.

Findings

Electron self-energy shows linear energy dependence due to graphene's bandstructure.

Dirac fermion velocity is reduced by 4-8% depending on doping.

Results align with experimental photoemission linewidth observations.

Abstract

We present a first-principles investigation of the phonon-induced electron self-energy in graphene. The energy dependence of the self-energy reflects the peculiar linear bandstructure of graphene and deviates substantially from the usual metallic behavior. The effective band velocity of the Dirac fermions is found to be reduced by 4-8%, depending on doping, by the interaction with lattice vibrations. Our results are consistent with the observed linear dependence of the electronic linewidth on the binding energy in photoemission spectra.