Plasmonics in graphene at infrared frequencies

Scientific paper - Original scientific paper

• Author: Marinko Jablan
• Author: Hrvoje Buljan
• Author: Marin Soljačić
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

We point out that plasmons in doped graphene simultaneously enable low-losses and significant wave localization for frequencies below that of the optical phonon branch hbar omega_{;Oph};\approx 0.2 eV. Large plasmon losses occur in the interband regime (via excitation of electron-hole pairs), which can be pushed towards higher frequencies for higher doping values. For sufficiently large dopings, there is a bandwidth of frequencies from omega_{;Oph}; up to the interband threshold, where a plasmon decay channel via emission of an optical phonon together with an electron-hole pair is nonegligible. The calculation of losses is performed within the framework of a random-phase approximation and number conserving relaxation-time approximation. The measured DC relaxation-time serves as an input parameter characterizing collisions with impurities, whereas the contribution from optical phonons is estimated from the influence of the electron-phonon coupling on the optical conductivity. Optical properties of plasmons in graphene are in many relevant aspects similar to optical properties of surface plasmons propagating on dielectric-metal interface, which have been drawing a lot of interest lately because of their importance for nanophotonics. Therefore, the fact that plasmons in graphene could have low losses for certain frequencies makes them potentially interesting for nanophotonic applications.

• Keywords (english): plasmons; losses; graphene; infrared
• 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. 80, no. 24, 245435
• p-ISSN: 1098-0121
• e-ISSN: 1550-235X
• DOI: https://doi.org/10.1103/PhysRevB.80.245435
• URN:NBN: urn:nbn:hr:217:223703
• Publication: 2009
• Project: Number: 119-0000000-1015; Title (croatian): Nelinearne pojave i valna dinamika u fotoničkim sustavima; Leader: Hrvoje Buljan; Jurisdiction: Croatia; Funding stream: ZP
• Document URL: http://link.aps.org/doi/10.1103/PhysRevB.80.245435
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright (2009) by the American Physical Society. Received 30 September 2009; published 23 December 2009.
• Created on: 2019-10-31 19:05:37