1. Raman Linewidth Contributions from Four-Phonon and Electron-Phonon Interactions in Graphene
- Author
-
Zherui HAN, Xiaolong Yang, Xiulin Ruan, Tianli Feng, Li Shi, Wu Li, and Sean Sullivan
- Subjects
Condensed Matter - Materials Science ,Condensed Matter::Materials Science ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter::Superconductivity ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Physics::Optics ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,General Physics and Astronomy ,Condensed Matter::Strongly Correlated Electrons ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect - Abstract
The Raman peak position and linewidth provide insight into phonon anharmonicity and electron-phonon interactions in materials. For monolayer graphene, prior first-principles calculations have yielded decreasing linewidth with increasing temperature, which is opposite to measurement results. Here, we explicitly consider four-phonon anharmonicity, phonon renormalization, and electron-phonon coupling, and find all to be important to successfully explain both the G peak frequency shift and linewidths in our suspended graphene sample over a wide temperature range. Four-phonon scattering contributes a prominent linewidth that increases with temperature, while temperature dependence from electron-phonon interactions is found to be reversed above a doping threshold (ℏω_{G}/2, with ω_{G} being the frequency of the G phonon).
- Published
- 2022