Changing character of electronic transitions in graphene: From single-particle excitations to plasmons

Scientific paper - Original scientific paper

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

Abstract (english)

In this paper we clarify the nature of π and π + σ electron excitations in pristine graphene. We clearly demonstrate the continuous transition from single particle to collective character of such excitations and how screening modifies their dispersion relations. We prove that π and π + σ plasmons do exist in graphene, though occurring only for a particular range of wave vectors and with finite damping rate. Particular attention is paid to comparing the theoretical results with available EELS measurements in optical (Q ≈ 0) and other (Q not equal 0) limits. The conclusions, based on microscopic numerical results, are confirmed in an approximate analytical approach.

• Keywords (english): Pi plasmon; graphene; EELS
• 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. 91, no. 19, 195407
• p-ISSN: 1098-0121
• e-ISSN: 1550-235X
• DOI: https://doi.org/10.1103/PhysRevB.91.195407
• URN:NBN: urn:nbn:hr:217:007139
• Publication: 2015
• Document URL: http://link.aps.org/doi/10.1103/PhysRevB.91.195407
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright (2015) by the American Physical Society. Received 15 April 2015; revised manuscript received 25 April 2015; published 11 May 2015.
• Created on: 2020-01-11 19:06:58