Strong phonon-plasmon coupled modes in the graphene/silicon carbide heterosystem
Koch RJ, Seyller T, Schaefer JA (2010)
Publication Type: Journal article
Publication year: 2010
Journal
Book Volume: 82
Journal Issue: 20
DOI: 10.1103/PhysRevB.82.201413
Abstract
We report on strong coupling of the charge-carrier plasmon \textgreekwPL in graphene with the surface-optical phonon \textgreekwSO of the underlying SiC(0001) substrate with low-electron concentration (n=1.2$\times$1015 cm$-$3) in the long-wavelength limit (qII->0). Energy-dependent energy-loss spectra give clear evidence of two coupled phonon-plasmon modes \textgreekw$±$ separated by a gap between \textgreekwSO(qII->0) and \textgreekwTO(qII->0), the transverse-optical-phonon mode, in particular, for higher primary electron energies (E0$≥$20 eV). A simplified model based on dielectric theory is able to simulate our energy-loss spectra as well as the dispersion of the two coupled phonon-plasmon modes \textgreekw$±$. In contrast, Liu and Willis Phys. Rev. B 81 081406 (2010) postulate in their recent publication no gap and a discontinuous dispersion curve with a one-peak structure from their energy-loss data.
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APA:
Koch, R.J., Seyller, T., & Schaefer, J.A. (2010). Strong phonon-plasmon coupled modes in the graphene/silicon carbide heterosystem. Physical Review B, 82(20). https://doi.org/10.1103/PhysRevB.82.201413
MLA:
Koch, R. J., Thomas Seyller, and J. A. Schaefer. "Strong phonon-plasmon coupled modes in the graphene/silicon carbide heterosystem." Physical Review B 82.20 (2010).
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