Berlin 2018 – scientific programme
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O: Fachverband Oberflächenphysik
O 11: Focus Session: Molecular Nanostructures on surfaces - New Concepts towards Complex Architectures I
O 11.6: Talk
Monday, March 12, 2018, 16:45–17:00, MA 004
DFT study of super-atom states in graphene nanoribbons — •Bernhard Kretz1 and Aran Garcia-Lekue1,2 — 1Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, E-20018 San Sebastian, Spain — 2IKERBASQUE, Basque Foundation for Science, E-48013 Bilbao, Spain
In the two dimensional plane of graphene image states exist in the vacuum region above and below the graphene layer.[1] Such states do not follow the atomic lattice modulation and behave as nearly-free electrons (NFE). When graphene is rolled into nanotubes or fullerenes, these states overlap giving rise to the emergence of 1D NFE bands or 0D Super-Atom Molecular Orbitals (SAMOs).[2,3] In this work, we analyze a similar scenario in a reduced dimension, when the extended image states are related to the 1D edge of graphene. Using density functional theory (DFT), we investigate the emergence of 1D-NFE states in graphene nanoribbons, and we propose a way to confine them by modulating the width of the ribbons periodically, thus effectively creating 0D-SAMOs. Interestingly, the existence of a related SAMO state in the central empty region of a carbon-based macromolecule has been recently reported.[4]
[1] V. M. Silkin, et al., Phys. Rev. B, 80, 121408(R), 2009
[2] S. Hu et al., Nano Lett. 10, 4830 (2010)
[3] M. Feng et al., Science, 320, 359-362, 2008
[4] J. Heuille et al. (submitted)