Survival of the Dirac points in rippled graphene

TL;DR

This paper investigates how rippling in graphene affects its electronic properties, showing that Dirac points persist with long-lived quasiparticles despite significant renormalization effects.

Contribution

It introduces a generalized Momentum Average approximation for honeycomb lattices to analyze rippled graphene at all coupling strengths.

Findings

Dirac points can shift position due to rippling

Fermi velocity can be significantly renormalized

Long-lived quasiparticles survive near Dirac points even at strong coupling

Abstract

We study the effects of the rippling of the graphene sheet on the quasiparticle dispersion. This is achieved using a generalization to the honeycomb lattice of the Momentum Average approximation, which is accurate for all coupling strengths and at all energies. We show that even though the position of the Dirac points may move and the Fermi speed can be renormalized significantly, quasiparticles with very long lifetimes survive near the Dirac points even for very strong couplings.