UV-active plasmons in alkali and alkaline-earth intercalated graphene

Scientific paper - Original scientific paper

• Author: Vito Despoja; MBZ: 255255
• Author: Leonardo Marušić; MBZ: 154115
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

The interband π and π + σ plasmons in pristine graphene and the Dirac plasmon in doped graphene are not applicable, since they are broad or weak, and weakly couple to an external longitudinal or electromagnetic probe. Therefore, the ab initio density functional theory is used to demonstrate that the chemical doping of the graphene by the alkali or alkaline-earth atoms dramatically changes the poor graphene excitation spectrum in the ultraviolet frequency range (4–10 eV). Four prominent modes are detected. Two of them are the intralayer plasmons with square-root dispersion, characteristic of the two-dimensional modes. The remaining two are the interlayer plasmons, very strong in the long-wavelength limit but damped for larger wave vectors. The optical absorption calculations show that the interlayer plasmons are both optically active, which makes these materials suitable for small-organic-molecule sensing. This is particularly intriguing because the optically active two-dimensional plasmons have not been detected in other materials.

• Keywords (english): graphene; plasmons; electronic structure
• 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
• Numbering: vol. 97, no. 20, 205426
• p-ISSN: 2469-9950
• e-ISSN: 2469-9969
• DOI: https://doi.org/10.1103/PhysRevB.97.205426
• URN:NBN: urn:nbn:hr:217:388405
• Publication: 2018
• Document URL: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.97.205426
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2018 American Physical Society. Received 2 March 2018; revised manuscript received 25 April 2018; published 16 May 2018.
• Created on: 2020-03-01 17:02:39