Chirality-induced Dynamic Kohn Anomalies in Graphene

Abstract

We develop a theory for the renormalization of the phonon energy dispersion in graphene due to the combined effects of both Coulomb and electron-phonon (e-ph) interactions. We obtain the renormalized phonon energy spectrum by an exact analytic derivation of the phonon self-energy, finding three distinct Kohn anomalies (KAs) at the phonon wavevector $q=\omega /v,2k_F\pm \omega /v$ for LO phonons and one at $q=\omega /v$ for TO phonons. The presence of these new KAs in graphene, in contrast to the usual KA $q=2k_F$ in ordinary metals, originates from the dynamical screening of e-ph interaction (with a concomitant breakdown of the Born-Oppenheimer approximation) and the peculiar chirality of the graphene e-ph coupling.

Accepted by PRL; updated version to appear in Physical Review Letters

References in corpus (4)

• Dielectric function, screening, and plasmons in 2D graphene
• Electric Field Effect Tuning of Electron-Phonon Coupling in Graphene
• Non-adiabatic Kohn-anomaly in a doped graphene monolayer
• Phonon-induced many-body renormalization of graphene electronic properties

Cited by in corpus (3)

• Electron-Phonon Interactions for Optical Phonon Modes in Few-Layer Graphene
• Interplay between 3d and 4f magnetism in CeCoPO
• Unconventional quasiparticle lifetime in undoped graphene