Large-amplitude coherent phonons and inverse Stone-Wales transitions in graphitic systems with defects interacting with ultrashort laser pulses

Felipe Valencia, Aldo H. Romero, Harald Olaf Jeschke, Martin E. Garcia

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

The mechanical response of a defective graphene layer to an ultrafast laser pulse is investigated through nonadiabatic molecular dynamics simulations. The defects are pentagon-heptagon pairs introduced by a single Stone-Wales transformation in the simulation cell. We found that when the fraction of excited electrons ξ is below 6%, the layer exhibits strong transversal displacements in the neighborhood of the defect. The amplitude of these movements increases with the amount of energy absorbed until the threshold of ξ=6% is reached. Under this condition the layer undergoes a subpicosecond inverse Stone-Wales transition, healing the defect. The absorbed energy per atom required to induce this mechanism is approximately 1.3 eV, a value that is below the laser damage thresholds for the pristine layers. The transition is lead by the electronic entropy and follows a path with strong out-of-plane contributions; it differs from the predicted path for thermally activated transitions, as calculated using standard transition state approaches. The same phenomenon is observed in defective zig-zag and armchair nanotubes. In contrast, for a defective C60 fullerene the mechanism is hindered by the presence of edge-sharing pentagons.

Original languageEnglish
Article number075409
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume74
Issue number7
DOIs
Publication statusPublished - 2006
Externally publishedYes

Fingerprint

Wales
Phonons
Ultrashort pulses
phonons
rocks
Defects
defects
pulses
lasers
Ultrafast lasers
Laser damage
Graphite
Fullerenes
Graphene
Nanotubes
laser damage
Molecular dynamics
Laser pulses
healing
Entropy

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

@article{9188156f42584edcb5f118d75ef95e1d,
title = "Large-amplitude coherent phonons and inverse Stone-Wales transitions in graphitic systems with defects interacting with ultrashort laser pulses",
abstract = "The mechanical response of a defective graphene layer to an ultrafast laser pulse is investigated through nonadiabatic molecular dynamics simulations. The defects are pentagon-heptagon pairs introduced by a single Stone-Wales transformation in the simulation cell. We found that when the fraction of excited electrons ξ is below 6{\%}, the layer exhibits strong transversal displacements in the neighborhood of the defect. The amplitude of these movements increases with the amount of energy absorbed until the threshold of ξ=6{\%} is reached. Under this condition the layer undergoes a subpicosecond inverse Stone-Wales transition, healing the defect. The absorbed energy per atom required to induce this mechanism is approximately 1.3 eV, a value that is below the laser damage thresholds for the pristine layers. The transition is lead by the electronic entropy and follows a path with strong out-of-plane contributions; it differs from the predicted path for thermally activated transitions, as calculated using standard transition state approaches. The same phenomenon is observed in defective zig-zag and armchair nanotubes. In contrast, for a defective C60 fullerene the mechanism is hindered by the presence of edge-sharing pentagons.",
author = "Felipe Valencia and Romero, {Aldo H.} and Jeschke, {Harald Olaf} and Garcia, {Martin E.}",
year = "2006",
doi = "10.1103/PhysRevB.74.075409",
language = "English",
volume = "74",
journal = "Physical Review B-Condensed Matter",
issn = "1098-0121",
publisher = "American Physical Society",
number = "7",

}

TY - JOUR

T1 - Large-amplitude coherent phonons and inverse Stone-Wales transitions in graphitic systems with defects interacting with ultrashort laser pulses

AU - Valencia, Felipe

AU - Romero, Aldo H.

AU - Jeschke, Harald Olaf

AU - Garcia, Martin E.

PY - 2006

Y1 - 2006

N2 - The mechanical response of a defective graphene layer to an ultrafast laser pulse is investigated through nonadiabatic molecular dynamics simulations. The defects are pentagon-heptagon pairs introduced by a single Stone-Wales transformation in the simulation cell. We found that when the fraction of excited electrons ξ is below 6%, the layer exhibits strong transversal displacements in the neighborhood of the defect. The amplitude of these movements increases with the amount of energy absorbed until the threshold of ξ=6% is reached. Under this condition the layer undergoes a subpicosecond inverse Stone-Wales transition, healing the defect. The absorbed energy per atom required to induce this mechanism is approximately 1.3 eV, a value that is below the laser damage thresholds for the pristine layers. The transition is lead by the electronic entropy and follows a path with strong out-of-plane contributions; it differs from the predicted path for thermally activated transitions, as calculated using standard transition state approaches. The same phenomenon is observed in defective zig-zag and armchair nanotubes. In contrast, for a defective C60 fullerene the mechanism is hindered by the presence of edge-sharing pentagons.

AB - The mechanical response of a defective graphene layer to an ultrafast laser pulse is investigated through nonadiabatic molecular dynamics simulations. The defects are pentagon-heptagon pairs introduced by a single Stone-Wales transformation in the simulation cell. We found that when the fraction of excited electrons ξ is below 6%, the layer exhibits strong transversal displacements in the neighborhood of the defect. The amplitude of these movements increases with the amount of energy absorbed until the threshold of ξ=6% is reached. Under this condition the layer undergoes a subpicosecond inverse Stone-Wales transition, healing the defect. The absorbed energy per atom required to induce this mechanism is approximately 1.3 eV, a value that is below the laser damage thresholds for the pristine layers. The transition is lead by the electronic entropy and follows a path with strong out-of-plane contributions; it differs from the predicted path for thermally activated transitions, as calculated using standard transition state approaches. The same phenomenon is observed in defective zig-zag and armchair nanotubes. In contrast, for a defective C60 fullerene the mechanism is hindered by the presence of edge-sharing pentagons.

UR - http://www.scopus.com/inward/record.url?scp=33747071776&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33747071776&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.74.075409

DO - 10.1103/PhysRevB.74.075409

M3 - Article

AN - SCOPUS:33747071776

VL - 74

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 1098-0121

IS - 7

M1 - 075409

ER -