Two-dimensional and π plasmon spectra in pristine and doped graphene

Scientific paper - Original scientific paper

• Author: Vito Despoja
• Author: Dino Novko
• Author: Krešimir Dekanić
• Author: Marijan Šunjić
• Author: Leonardo Marušić
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

The spectra of electronic excitations in graphene are calculated using first principles time-dependent density functional theory formalism, and used to obtain π and π+σ plasmon dispersion curves. The spectra and dispersion are in excellent agreement with recent experimental results, and they are used to investigate the anisotropy and splitting of a π plasmon, which has also been experimentally verified. The high accuracy of this calculation enabled the discovery of some different features in the spectra, especially the ΓM-ΓK anisotropy of the two-dimensional (2D) plasmon dispersion curve, which qualitatively agrees with recent experimental results. Our ab initio 2D plasmon dispersion curves are compared with the ones obtained in some recently proposed 2D models. They show strong disagreement with the dispersion curve obtained using a simple one-band 2D theory, as well as some discrepancies with respect to the commonly used Das Sarma et al.'s dispersion curve, even in the isotropic region. Excellent agreement of the calculated spectrum in pristine graphene with the electron energy loss spectroscopy spectrum measured for lower momentum transfers is demonstrated.

• Keywords (english): doped graphene; pristine graphene; π plasmon spectra; surface; excitations; phase; films; ions; gas
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical review B: Condensed matter and materials physics
• Numbering: vol. 87, no. 7, 075447
• p-ISSN: 1098-0121
• e-ISSN: 1550-235X
• DOI: https://doi.org/10.1103/PhysRevB.87.075447
• URN:NBN: urn:nbn:hr:217:035890
• Publication: 2013
• Document URL: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.87.075447
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright (2013) by the American Physical Society. Received 7 September 2012; revised manuscript received 4 December 2012; published 27 February 2013.
• Created on: 2019-11-24 12:49:55