Kohn Anomalies in Graphene Nanoribbons

Abstract

The quantum corrections to the energies of the $\Gamma$ point optical phonon modes (Kohn anomalies) in graphene nanoribbons are investigated. We show theoretically that the longitudinal optical modes undergo a Kohn anomaly effect, while the transverse optical modes do not. In relation to Raman spectroscopy, we show that the longitudinal modes are not Raman active near the zigzag edge, while the transverse optical modes are not Raman active near the armchair edge. These results are useful for identifying the orientation of the edge of graphene nanoribbons by G band Raman spectroscopy, as is demonstrated experimentally. The differences in the Kohn anomalies for nanoribbons and for metallic single wall nanotubes are pointed out, and our results are explained in terms of pseudospin effects.

11 pages, 6 figures

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Cited by in corpus (18)

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• Quantifying defects in graphene via Raman spectroscopy at different excitation energies
• Graphene nanoribbons from unzipped carbon nanotubes: atomic structures, Raman spectroscopy and electrical properties
• Theory of optical transitions in graphene nanoribbons
• Optical selection rules of zigzag graphene nanoribbons
• Determination of Edge Purity in Bilayer Graphene Using micro-Raman Spectroscopy
• Identifying the Orientation of Edge of Graphene Using G Band Raman Spectra
• Emergence of a ZO Kohn anomaly in quasi-freestanding epitaxial graphene
• Bottom-up fabrication of atomically precise graphene nanoribbons
• Kohn Anomaly in Raman Spectroscopy of Single Wall Carbon Nanotubes
• Electron Wave Function in Armchair Graphene Nanoribbons
• Graphene nanoribbons on vicinal SiC surfaces by molecular beam epitaxy
• Berry's Phase for Standing Wave Near Graphene Edge
• Spectroscopic investigations of phonons in epitaxial graphene
• Polarization Dependence of Raman Spectra in Strained Graphene
• Kohn anomaly of optical zone boundary phonons in uniaxial strained graphene: role of the electronic band structure
• Raman study on G mode of graphene for determination of edge orientation
• Renormalization of the optical band gap through an effective Thirring interaction for massive Dirac-like electrons