Phonon Self-Energy Corrections to Nonzero Wave-Vector Phonon Modes in Single-Layer Graphene
Name
Araujo-2012-Phonon Self-Energy Corrections to Nonzero Wave-Vector.pdf
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Author(s)
Araujo, Paulo Antonio Trinidade
Mafra, Daniela Lopes
Sato, K.
Saito, R.
Kong, Jing
Dresselhaus, Mildred
Date Issued
July 2012
Journal
Physical Review Letters
Publisher
American Physical Society
Citation
Araujo, P. et al. “Phonon Self-Energy Corrections to Nonzero Wave-Vector Phonon Modes in Single-Layer Graphene.” Physical Review Letters 109.4 (2012). © 2012 American Physical Society
Version
Final published version
Abstract
Phonon self-energy corrections have mostly been studied theoretically and experimentally for phonon modes with zone-center (q=0) wave vectors. Here, gate-modulated Raman scattering is used to study phonons of a single layer of graphene originating from a double-resonant Raman process with q≠0. The observed phonon renormalization effects are different from what is observed for the zone-center q=0 case. To explain our experimental findings, we explored the phonon self-energy for the phonons with nonzero wave vectors (q≠0) in single-layer graphene in which the frequencies and decay widths are expected to behave oppositely to the behavior observed in the corresponding zone-center q=0 processes. Within this framework, we resolve the identification of the phonon modes contributing to the G[superscript ⋆] Raman feature at 2450 cm[superscript -1] to include the iTO+LA combination modes with q≠0 and also the 2iTO overtone modes with q=0, showing both to be associated with wave vectors near the high symmetry point K in the Brillouin zone.
MIT Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Massachusetts Institute of Technology. Department of Physics
Massachusetts Institute of Technology. Research Laboratory of Electronics
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DOI of Published Version
https://doi.org/10.1103/PhysRevLett.109.046801
