We employ the formalism of bond currents, expressed in terms of the nonequilibrium Green functions, to image the charge flow between two sites of the honeycomb lattice of graphene ribbons of few nanometers width. In sharp contrast to nonrelativistic electrons, current density profiles of quantum transport at energies close to the Dirac point in clean zigzag graphene nanoribbons (ZGNR) differs m...

We study by density functional and large scale tight-binding transport calculations the electronic structure, magnetism and transport properties of the recently proposed graphene ribbons with edges rolled to form nanotubes. Edges with armchair nanotubes present magnetic moments localized either in the tube or the ribbon and metallic or half-metallic character, depending on the symmetry of the j...

The recent discovery of graphene (Novoselov et al., 2004), a single atomic sheet of graphite, has ignited intense research activities to explore the electronic properties of this novel twodimensional (2D) electronic system. Charge transport in graphene differs from that in conventional 2D electronic systems as a consequence of the conical energy dispersion relation near the charge neutrality (D...

We study the conductance through two types of graphene nanostructures: nanoribbon junctions in which the width changes from wide to narrow, and curved nanoribbons. In the wide-narrow structures, substantial reflection occurs from the wide-narrow interface, in contrast to the behavior of the much studied electron gas waveguides. In the curved nanoribbons, the conductance is very sensitive to det...

The mechanical properties of graphene nanoribbons on Ni(111) surfaces with different contact sizes are investigated by means of density functional theory. For finite contact sizes, the stress behavior of graphene nanoribbons on metal electrodes is likely to be similar to that of suspended graphene, however the critical strain is not reached due to the sliding friction at the interface. The comp...

We demonstrate numerically that armchair graphene nanoribbons can support vibrational localized states in the form of surface solitons. Such localized states appear through self-localization of the vibrational energy along the edge of the graphene nanoribbon, and they decay rapidly inside the structure. We find five types of such solitary waves including in-plane and out-of-plane edge breathers...

Graphene nanoribbons (GNR) are one of the most promising candidates for the fabrication of graphene-based nanoelectronic devices such as high mobility field effect transistors (FET). Here, we report a high-yield fabrication of a high quality another type of GNR analogue, fully flattened carbon nanotubes (flattened CNTs), using solution-phase extraction of inner tubes from large-diameter multi-w...

The transmission properties of armchair graphene nanoribbon junctions between graphene electrodes are investigated by means of first-principles quantum transport calculations. First the dependence of the transmission function on the size of the nanoribbon has been studied. Two regimes are highlighted: for a small applied bias transport takes place via tunneling and the length of the ribbon is t...

We reveal that there exists a class of graphene structures (a subclass of bilayer graphene nanoribbons) which has an exceptionally strong optical response in the terahertz (THz) and far infrared (FIR) regime. The peak conductance of THz/FIR active bilayer ribbons is around 2 orders of magnitude higher than the universal conductance of sigma(0) = e(2)/4variant Planck's over 2pi observed in graph...