Kohn anomaly and interplay of electron-electron and electron-phonon interactions in epitaxial graphene

Date
Authors
Zhou, S. Y.
Siegel, D. A.
Fedorov, A. V.
Lanzara, A.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Description
The interplay of electron-phonon (el-ph) and electron-electron (el-el) interactions in epitaxial graphene is studied by directly probing its electronic structure. We found a strong coupling of electrons to the soft part of the A1g phonon evident by a kink at 150+/-15 meV, while the coupling of electrons to another expected phonon E2g at 195 meV can only be barely detected. The possible role of the el-el interaction to account for the enhanced coupling of electrons to the A1g phonon, and the contribution of el-ph interaction to the linear imaginary part of the self energy at high binding energy are also discussed. Our results reveal the dominant role of the A1g phonon in the el-ph interaction in graphene, and highlight the important interplay of el-el and el-ph interactions in the self energy of graphene.
Comment: accepted to Phys. Rev. B
Keywords
Condensed Matter - Materials Science, Condensed Matter - Strongly Correlated Electrons
Citation
Collections