Electronic transport across linear defects in graphene

We investigate the low-energy electronic transport across grain boundaries in graphene ribbons and infinite flakes. Using the recursive Green’s function method, we calculate the electronic transmission across different types of grain boundaries in graphene ribbons. We show results for the charge density distribution and the current flow along the ribbon. We study linear defects at various angles with the ribbon direction, as well as overlaps of two monolayer ribbon domains forming a bilayer region. For a class of extended defect lines with periodicity 3, an analytic approach is developed to study transport in infinite flakes. This class of extended grain boundaries is particularly interesting, since the K and K0 Dirac points are superposed. NMRP acknowledges support from EC under Graphene Flagship (Contract No. CNECT-ICT-604391) and the hospitality of the Instituto de Física of the UFRJ, where this work was completed. JNBR acknowledges Singapore National Research Foundation for its support through the Fellowship Program NRFNRFF2012-01. CJP and ALCP acknowledge So Paulo Research Foundation (FAPESP), grant 2012/19060-0. Part of the numerical simulations were performed at the computational facilities from CENAPAD-SP, at Campinas State University.