title: Kinks in the σ band of graphene induced by electron-phonon coupling.
abstract: Angle-resolved photoemission spectroscopy reveals pronounced kinks in the dispersion of the σ band of graphene. Such kinks are usually caused by the combination of a strong electron-boson interaction and the cutoff in the Fermi-Dirac distribution. They are therefore not expected for the σ band of graphene that has a binding energy of more than ≈3.5 eV. We argue that the observed kinks are indeed caused by the electron-phonon interaction, but the role of the Fermi-Dirac distribution cutoff is assumed by a cutoff in the density of σ states. The existence of the effect suggests a very weak coupling of holes in the σ band not only to the π electrons of graphene but also to the substrate electronic states. This is confirmed by the presence of such kinks for graphene on several different substrates that all show a strong coupling constant of λ≈1.
authors: Department of Physics, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway.
authors: Federico
authors: F
authors: Mazzola
authors: Justin W
authors: JW
authors: Wells
authors: Rositza
authors: R
authors: Yakimova
authors: Søren
authors: S
authors: Ulstrup
authors: Jill A
authors: JA
authors: Miwa
authors: Richard
authors: R
authors: Balog
authors: Marco
authors: M
authors: Bianchi
authors: Mats
authors: M
authors: Leandersson
authors: Johan
authors: J
authors: Adell
authors: Philip
authors: P
authors: Hofmann
authors: T
authors: T
authors: Balasubramanian