• 文献标题:   Observation of the Kohn anomaly near the K point of bilayer graphene
  • 文献类型:   Article
  • 作  者:   MAFRA DL, MALARD LM, DOORN SK, HTOON H, NILSSON J, NETO AHC, PIMENTA MA
  • 作者关键词:   electronic structure, electronphonon interaction, graphene, infrared spectra, phonon dispersion relation, raman spectra, soft mode, tightbinding calculation, visible spectra
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   1098-0121
  • 通讯作者地址:   Univ Fed Minas Gerais
  • 被引频次:   23
  • DOI:   10.1103/PhysRevB.80.241414
  • 出版年:   2009

▎ 摘  要

The dispersion of electrons and phonons near the K point of bilayer graphene was investigated in a resonant Raman study using different laser excitation energies in the near-infrared and visible range. The electronic structure was analyzed within the tight-binding approximation, and the Slonczewski-Weiss-McClure parameters were obtained from the analysis of the dispersive behavior of the Raman features. A softening of the phonon branches was observed near the K point and results evidence the Kohn anomaly and the importance of considering electron-phonon and electron-electron interactions to correctly describe the phonon dispersion in graphene systems, confirming the theoretical predictions by Lazzeri.