Interplay between edge states and simple bulk defects in graphene nanoribbons
arXiv:1205.5146 · doi:10.1140/epjb/e2013-30488-6
Abstract
We study the interplay between the edge states and a single impurity in a zigzag graphene nanoribbon. We use tight-binding exact diagonalization techniques, as well as density functional theory calculations to obtain the eigenvalue spectrum, the eigenfunctions, as well the dependence of the local density of states (LDOS) on energy and position. We note that roughly half of the unperturbed eigenstates in the spectrum of the finite-size ribbon hybridize with the impurity state, and the corresponding eigenvalues are shifted with respect to their unperturbed values. The maximum shift and hybridization occur for a state whose energy is inverse proportional to the impurity potential; this energy is that of the impurity peak in the DOS spectrum. We find that the interference between the impurity and the edge gives rise to peculiar modifications of the LDOS of the nanoribbon, in particular to oscillations of the edge LDOS. These effects depend on the size of the system, and decay with the distance between the edge and the impurity.
10 pages, 15 figures, revtex4
References in corpus (15)
- The electronic properties of graphene
- Half-Metallic Graphene Nanoribbons
- Edge-functionalized and substitutional doped graphene nanoribbons: electronic and spin properties
- Electron scattering on microscopic corrugations in graphene
- The Zak phase and the existence of edge states in graphene
- Friedel oscillations, impurity scattering and temperature dependence of resistivity in graphene
- Electron states of mono- and bilayer graphene on SiC probed by STM
- Quasiparticle Chirality in Epitaxial Graphene Probed at the Nanometer Scale
- Edge Effects in Finite Elongated Graphene Nanoribbons
- Effect of a single impurity on the local density of states in monolayer and bilayer graphene
- Impurity effects in a two--dimensional system with Dirac spectrum
- Electron waves in chemically substituted graphene
- Average Density of States in Disordered Graphene systems
- A comparative study of density functional and density functional tight binding calculations of defects in graphene
- Scanning Tunneling Microscopy and Spectroscopy of Graphene on Insulating Substrates