Electron polarization function and plasmons in metallic armchair graphene nanoribbons

Autor: Shylau, A. A., Badalyan, S. M., Peeters, F. M., Jauho, A. P.
Rok vydání: 2015
Předmět:
Zdroj: Phys. Rev. B 91, 205444, 29 May 2015
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevB.91.205444
Popis: We calculate the polarization function of Dirac fermions in metallic armchair graphene nanoribbons for an arbitrary temperature and doping. We find that at finite temperatures due to the phase space redistribution among inter-band and intra-band electronic transitions in the conduction and valence bands, the full polarization function becomes independent of the temperature and the position of the chemical potential. As a result, for a given width of nanoribbons there exists a single plasmon mode, with the energy dispersion determined by the graphene's fine structure constant. In Coulomb-coupled nanoribbons, this plasmon splits into the basic in-phase and out-of-phase plasmon modes, with the splitting energy determined additionally by the inter-ribbon spacing.
Comment: 7 pages, 4 figures; in press in Phys. Rev. B
Databáze: arXiv