title: Current-induced runaway vibrations in dehydrogenated graphene nanoribbons.
abstract: We employ a semi-classical Langevin approach to study current-induced atomic dynamics in a partially dehydrogenated armchair graphene nanoribbon. All parameters are obtained from density functional theory. The dehydrogenated carbon dimers behave as effective impurities, whose motion decouples from the rest of carbon atoms. The electrical current can couple the dimer motion in a coherent fashion. The coupling, which is mediated by nonconservative and pseudo-magnetic current-induced forces, change the atomic dynamics, and thereby show their signature in this simple system. We study the atomic dynamics and current-induced vibrational instabilities using a simplified eigen-mode analysis. Our study illustrates how armchair nanoribbons can serve as a possible testbed for probing the current-induced forces.
authors.affiliation: Center for Nanostructured Graphene (CNG), Department of Micro- and Nanotechnology, Technical University of Denmark, Ørsteds Plads, Bldg. 345E, DK-2800 Kongens Lyngby, Denmark.
authors.forename: Rasmus Bjerregaard
authors.initials: RB
authors.lastname: Christensen
authors.affiliation: School of Physics, Huazhong University of Science and Technology, 430074 Wuhan, P. R. China.
authors.forename: Jing-Tao
authors.initials: JT
authors.lastname: Lü
authors.affiliation: Niels-Bohr Institute and Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Hedegård
authors.affiliation: Center for Nanostructured Graphene (CNG), Department of Micro- and Nanotechnology, Technical University of Denmark, Ørsteds Plads, Bldg. 345E, DK-2800 Kongens Lyngby, Denmark.
authors.forename: Mads
authors.initials: M
authors.lastname: Brandbyge
keywords: current-induced forces; density functional theory (NEGF-DFT); graphene; molecular electronics