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Lattice vibrations in graphene nanoribbons from density functional theory
Author(s) -
Gillen Roland,
Mohr Marcel,
Maultzsch Janina,
Thomsen Christian
Publication year - 2009
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200982343
Subject(s) - zigzag , phonon , graphene nanoribbons , condensed matter physics , brillouin zone , graphene , materials science , density functional theory , lattice (music) , physics , nanotechnology , quantum mechanics , geometry , mathematics , acoustics
This work shows results of our investigation of the lattice vibrations in graphene nanoribbons with zigzag and armchair type edges, which we performed by the use of density functional theory. The boundary conditions induced by the nanoribbon edges allow for an interpretation of the phonons as fundamental modes and their respective overtones. The calculated phonons show a characteristic dependence on the nanoribbon width. In this context, we considered a possible influence of the antiferromagnetic ground state of zigzag nanoribbons with respect to the phonons. Furthermore, we demonstrate that a mapping of the calculated Γ‐point phonon frequencies of nanoribbons onto the phonon dispersion of graphene corresponds to an “unfolding” of the nanoribbons' Brillouin zone onto that of graphene and yields good agreement. We further show symmetry properties of armchair and zigzag nanoribbons and full phonon dispersions for small‐width nanoribbons.