Changing character of electronic transitions in graphene: From single-particle excitations to plasmons
| Autor: | Marijan Šunjić, Dino Novko, Vito Despoja |
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| Přispěvatelé: | Donostia International Physics Center |
| Rok vydání: | 2015 |
| Předmět: |
EELS
FOS: Physical sciences Electron law.invention Pi plasmon graphene law Quantum mechanics Dispersion relation Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Plasmon Physics Condensed Matter - Materials Science Range (particle radiation) Condensed Matter - Mesoscale and Nanoscale Physics Condensed matter physics Graphene Sigma Materials Science (cond-mat.mtrl-sci) Condensed Matter Physics NATURAL SCIENCES. Physics Electronic Optical and Magnetic Materials PRIRODNE ZNANOSTI. Fizika Atomic electron transition Quasiparticle |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname Physical review B: Condensed matter and materials physics Volume 91 Issue 19 |
| ISSN: | 1098-0121 1550-235X |
| DOI: | 10.1103/PhysRevB.91.195407 |
| Popis: | Under the terms of the Creative Commons Attribution License 3.0 (CC-BY). 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≠0) limits. The conclusions, based on microscopic numerical results, are confirmed in an approximate analytical approach. The authors are grateful to Donostia International Physics Center (DIPC) and Pedro M. Echenique for hospitality and financial support during various stages of this work. |
| Databáze: | OpenAIRE |
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