Phonon surface mapping of graphite: Disentangling quasi-degenerate phonon dispersions

Autor(en)

Alexander Grüneis, J Serrano, A Bosak, M Lazzeri, S.L. Molodtsov, Ludger Wirtz, Claudio Attaccalite, M Krisch, Angel Rubio, F Mauri, Thomas Pichler

Abstrakt

The two-dimensional mapping of the phonon dispersions around the K point of graphite by inelastic x-ray scattering is provided. The present work resolves the longstanding issue related to the correct assignment of transverse and longitudinal phonon branches at K. We observe an almost degeneracy of the three TO-, LA-, and LO-derived phonon branches and a strong phonon trigonal warping. Correlation effects renormalize the Kohn anomaly of the TO mode, which exhibits a trigonal warping effect opposite to that of the electronic band structure. We determined the electron-phonon coupling constant to be 166 (eV/Å)2 in excellent agreement to GW calculations. These results are fundamental for understanding angle-resolved photoemission, double-resonance Raman and transport measurements of graphene-based systems.

Organisation(en)

Elektronische Materialeigenschaften

Externe Organisation(en)

Universitat Politècnica de Catalunya, European Synchrotron Radiation Facility ESRF, Université Paris VI - Pierre-et-Marie-Curie, Technische Universität Dresden, Institute for Electronics, Microelectronics, and Nanotechnology (CNRS UMR 8520), University of the Basque Country

Journal

Physical Review B

Band

80

Anzahl der Seiten

5

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.80.085423

Publikationsdatum

2009

Peer-reviewed

Ja

ÖFOS 2012

103015 Kondensierte Materie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/e5cba47d-66ab-43cc-9491-a50809a1111d