We study vibrational states localized at the edges of graphene nanoribbons. Such surface oscillations can be considered as a phonon analog of Tamm states in the electronic theory. We consider both armchair and zigzag graphene stripes and demonstrate that surface modes correspond to phonons localized at the edges of the graphene nanoribbon, and they can be classified as in-plane and out-of-plane...

Ned Block (2002) claims that there is “an epistemic tension” between two fairly widely held commitments: to phenomenal realism and to naturalism. Phenomenal realism is the view that (a) we are phenomenally consciousness, and that (b) there is no a priori or armchair sufficient condition for phenomenal consciousness that can be stated (noncircularly) in nonphenomenal terms (p.392). Block points ...

The structure of single walled armchair and zig-zag carbon nanotubes having 70 atoms and two carbons replaced by boron or nitrogen is obtained at minium energy using HF/6-31G* molecular orbital theory. The calculations show that the ground state of the zig-zag tubes is a triplet state while for the armchair tubes it is a singlet. In the zig-zag tubes the density of states at the Fermi level is ...

Submitted for the MAR10 Meeting of The American Physical Society Half-metallic Armchair Graphene Nanoribbon FUMIYUKI ISHII, KEISUKE SAWADA, MINEO SAITO, Kanazawa University — Among a variety of applications of graphenes, spintronics applications are considered to be hopeful. For an example, spin transport has been experimentally observed by using graphene layers [1]. There are two types of shap...

We show that the photoluminescence intensity of single-walled carbon nanotubes is much stronger in tubes with large chiral angles--armchair tubes--because exciton resonances make the luminescence of zigzag tubes intrinsically weak. This exciton-exciton resonance depends on the electronic structure of the tubes and is found more often in nanotubes of the +1 family. Armchair tubes do not necessar...

In this paper we propose an analytical method to calculate the band structures of graphene-like nanoribbons of the armchair type with arbitrary line defects or uniaxial strains. The model is based on the tight-binding model and the standing wave assumption for the armchair nanoribbons. It gives accurate band results for large supercell systems. Within this method, we analyze different local sta...

First-principles computations were carried out to predict the stability and magnetic and electronic properties of MoS2 nanoribbons with either zigzag- or armchair-terminated edges. Zigzag nanoribbons show the ferromagnetic and metallic behavior, irrespective of the ribbon width and thickness. Armchair nanoribbons are nonmagnetic and semiconducting, and the band gaps converge to a constant value...

We report an atomically resolved scanning tunneling microscopy investigation of the edges of graphene grains synthesized on Cu foils by chemical vapor deposition. Most of the edges are macroscopically parallel to the zigzag directions of graphene lattice. These edges have microscopic roughness that is found to also follow zigzag directions at atomic scale, displaying many ∼120° turns. A promine...

We present a microscopic theory for interacting graphene armchair nanoribbon quantum dots. Long-range interaction processes are responsible for Coulomb blockade and spin-charge separation. Short-range ones, arising from the underlying honeycomb lattice of graphene smear the spin-charge separation and induce exchange correlations between bulk electrons —delocalized on the ribbon— and single elec...