Two-Dimensional Analysis of the Double-Resonant 2D Raman Mode in Bilayer Graphene
Abstract
By computing the double-resonant Raman scattering cross section completely from first principles and including the electron-electron interaction at the G W level, we unravel the dominant contributions for the double-resonant 2D mode in bilayer graphene. We show that, in contrast to previous works, the so-called inner processes are dominant and that the 2D-mode line shape is described by three dominant resonances around the K point. We show that the splitting of the transversal optical (TO) phonon branch in the Γ -K direction, as large as 12 cm-1 in the G W approximation, is of great importance for a thorough description of the 2D-mode line shape. Finally, we present a method to extract the TO phonon splitting and the splitting of the electronic bands from experimental data.
- Publication:
-
Physical Review Letters
- Pub Date:
- October 2014
- DOI:
- 10.1103/PhysRevLett.113.187401
- arXiv:
- arXiv:1410.1316
- Bibcode:
- 2014PhRvL.113r7401H
- Keywords:
-
- 78.67.Wj;
- 63.22.Rc;
- 78.30.-j;
- 81.05.ue;
- Infrared and Raman spectra;
- Condensed Matter - Mesoscale and Nanoscale Physics
- E-Print:
- 5 pages Main + 6 pages Supplementary Material. Accepted for publication in Physical Review Letters