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

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

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(s)
Electronic Properties of Materials
External organisation(s)
Technische Universität Dresden, Institute for Electronics, Microelectronics, and Nanotechnology (CNRS UMR 8520), University of the Basque Country, Universitat Politècnica de Catalunya, European Synchrotron Radiation Facility ESRF
Journal
Physical Review B
Volume
80
No. of pages
5
ISSN
1098-0121
DOI
https://doi.org/10.1103/PhysRevB.80.085423
Publication date
2009
Peer reviewed
Yes
Austrian Fields of Science 2012
103015 Condensed matter
Portal url
https://ucrisportal.univie.ac.at/en/publications/e5cba47d-66ab-43cc-9491-a50809a1111d