We calculate the local current density in pristine armchair graphene nanoribbons (AGNRs) with varying width, NC, employing a density-functional-theory-based ab initio transport formalism. We observe very pronounced current patterns (streamlines) with threefold periodicity in NC. They arise as a consequence of quantum confinement in the transverse flow direction. Neighboring streamlines are separated by stripes of almost vanishing flow. As a consequence, the response of the current to functionalizing adsorbates is very sensitive to their placement: adsorbates located within the current filaments lead to strong backscattering, while adsorbates placed in other regions have almost no impact at all.
@article{arxiv.1405.3205,
title = {Ab initio quantum transport through armchair graphene nanoribbons: Streamlines in the current density},
author = {Jan Wilhelm and Michael Walz and Ferdinand Evers},
journal= {arXiv preprint arXiv:1405.3205},
year = {2014}
}