Atomically precise tailoring of graphene can enable unusual transport pathways and new nanometer-scale functional devices. Here we describe a recipe for the controlled production of highly regular "5-5-8" line defects in graphene by means of simultaneous electron irradiation and Joule heating by applied electric current. High-resolution transmission electron microscopy reveals individual steps of the growth process. Extending earlier theoretical work suggesting valley-discriminating capabilities of a graphene 5-5-8 line defect, we perform first-principles calculations of transport and find a strong energy dependence of valley polarization of the charge carriers across the defect. These findings inspire us to propose a compact electrostatically gated "valley valve" device, a critical component for valleytronics.
@article{arxiv.1406.0887,
title = {Controlled Growth of a Line Defect in Graphene and Implications for Gate-Tunable Valley Filtering},
author = {J. -H. Chen and G. Autès and N. Alem and F. Gargiulo and A. Gautam and M. Linck and C. Kisielowski and O. V. Yazyev and S. G. Louie and A. Zettl},
journal= {arXiv preprint arXiv:1406.0887},
year = {2014}
}