title: Tight-binding approach to penta-graphene.
abstract: We introduce an effective tight-binding model to discuss penta-graphene and present an analytical solution. This model only involves the π-orbitals of the sp(2)-hybridized carbon atoms and reproduces the two highest valence bands. By introducing energy-dependent hopping elements, originating from the elimination of the sp(3)-hybridized carbon atoms, also the two lowest conduction bands can be well approximated - but only after the inclusion of a Hubbard onsite interaction as well as of assisted hopping terms. The eigenfunctions can be approximated analytically for the effective model without energy-dependent hopping elements and the optical absorption is discussed. We find large isotropic absorption ranging from 7.5% up to 24% for transitions at the Γ-point.
authors.affiliation: Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid, Spain.
authors.forename: T
authors.initials: T
authors.lastname: Stauber
authors.affiliation: Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid, Spain.|GFMC and Instituto Pluridisciplinar, Departamento de Física Aplicada III, Universidad Complutense de Madrid, 28040 Madrid, Spain.|IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid, Spain.
authors.forename: J I
authors.initials: JI
authors.lastname: Beltrán
authors.affiliation: Institute for Theoretical Physics, University of Regensburg, D-93040 Regensburg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Schliemann