Dynamic and charge doping effects on the phonon dispersion of graphene

Valentin Popov, P. Lambin

Research output: Contribution to journalArticle

Abstract

The phonon dispersion of graphene is calculated using a perturbative approach within a density-functional-based nonorthogonal tight-binding model. In the adiabatic approximation, the LO and the TO phonon branches are found to have a finite slope at the Γ and K points of the Brillouin zone, respectively. This linear behavior is due to strong electron-phonon coupling for electron wave vector close to the K point and is a signature of the Kohn anomaly. The explicit account of the dynamic effects results in a strong modification of these phonon branches as well as in a significant broadening of their linewidth in the vicinity of the Γ and K points. In particular, the finite slope of the phonon branches turns to zero. The charge doping of graphene changes the LO and TO branches in the vicinity of the two points and essentially removes the Kohn anomaly with the increase in the doping level. The obtained results are in a good agreement with available experimental data.
Original languageEnglish
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume82
Issue number4
DOIs
Publication statusPublished - 8 Jul 2010

Fingerprint

Graphite
Graphene
graphene
Doping (additives)
anomalies
slopes
Electrons
Brillouin zones
Linewidth
electrons
signatures
approximation

Cite this

@article{ceb8f78d664c4d8d959d393f5db9a5c7,
title = "Dynamic and charge doping effects on the phonon dispersion of graphene",
abstract = "The phonon dispersion of graphene is calculated using a perturbative approach within a density-functional-based nonorthogonal tight-binding model. In the adiabatic approximation, the LO and the TO phonon branches are found to have a finite slope at the Γ and K points of the Brillouin zone, respectively. This linear behavior is due to strong electron-phonon coupling for electron wave vector close to the K point and is a signature of the Kohn anomaly. The explicit account of the dynamic effects results in a strong modification of these phonon branches as well as in a significant broadening of their linewidth in the vicinity of the Γ and K points. In particular, the finite slope of the phonon branches turns to zero. The charge doping of graphene changes the LO and TO branches in the vicinity of the two points and essentially removes the Kohn anomaly with the increase in the doping level. The obtained results are in a good agreement with available experimental data.",
author = "Valentin Popov and P. Lambin",
year = "2010",
month = "7",
day = "8",
doi = "10.1103/PhysRevB.82.045406",
language = "English",
volume = "82",
journal = "Physical Review B - Condensed Matter and Materials Physics",
issn = "2469-9950",
publisher = "American Institute of Physics Publising LLC",
number = "4",

}

Dynamic and charge doping effects on the phonon dispersion of graphene. / Popov, Valentin; Lambin, P.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 82, No. 4, 08.07.2010.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Dynamic and charge doping effects on the phonon dispersion of graphene

AU - Popov, Valentin

AU - Lambin, P.

PY - 2010/7/8

Y1 - 2010/7/8

N2 - The phonon dispersion of graphene is calculated using a perturbative approach within a density-functional-based nonorthogonal tight-binding model. In the adiabatic approximation, the LO and the TO phonon branches are found to have a finite slope at the Γ and K points of the Brillouin zone, respectively. This linear behavior is due to strong electron-phonon coupling for electron wave vector close to the K point and is a signature of the Kohn anomaly. The explicit account of the dynamic effects results in a strong modification of these phonon branches as well as in a significant broadening of their linewidth in the vicinity of the Γ and K points. In particular, the finite slope of the phonon branches turns to zero. The charge doping of graphene changes the LO and TO branches in the vicinity of the two points and essentially removes the Kohn anomaly with the increase in the doping level. The obtained results are in a good agreement with available experimental data.

AB - The phonon dispersion of graphene is calculated using a perturbative approach within a density-functional-based nonorthogonal tight-binding model. In the adiabatic approximation, the LO and the TO phonon branches are found to have a finite slope at the Γ and K points of the Brillouin zone, respectively. This linear behavior is due to strong electron-phonon coupling for electron wave vector close to the K point and is a signature of the Kohn anomaly. The explicit account of the dynamic effects results in a strong modification of these phonon branches as well as in a significant broadening of their linewidth in the vicinity of the Γ and K points. In particular, the finite slope of the phonon branches turns to zero. The charge doping of graphene changes the LO and TO branches in the vicinity of the two points and essentially removes the Kohn anomaly with the increase in the doping level. The obtained results are in a good agreement with available experimental data.

UR - http://www.scopus.com/inward/record.url?scp=77956680977&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.82.045406

DO - 10.1103/PhysRevB.82.045406

M3 - Article

VL - 82

JO - Physical Review B - Condensed Matter and Materials Physics

JF - Physical Review B - Condensed Matter and Materials Physics

SN - 2469-9950

IS - 4

ER -