Regensburg 2019 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 14: Graphene

TT 14.6: Talk

Monday, April 1, 2019, 16:15–16:30, H22

Interatomic forces in current-carrying graphene nanojunctions — •Susanne Leitherer, Nick R. Papior, and Mads Brandbyge — Department of Micro- and Nanotechnology, Technical University of Denmark

The interplay between the applied field, current and the atomic structure in ballistic nanoscale conductors carrying a substantial current, as seen in experiments [1,2], is still not well understood. In this contribution, we study the non-equilibrium charge transport through nanojunctions with graphene electrodes, employing first principles electronic structure and transport calculations based on density functional theory combined with non-equilibrium Greens functions (DFT-NEGF) [3]. We calculate the forces on the atoms which are induced by a finite bias voltage. The junctions are gated to increase their conductance and to allow switching between electron and hole-dominated transport [4]. We discuss the role of the potential drop in the junction, and show how the forces can be rationalized in terms of bond-currents, charge redistribution and overlap populations.
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N. Papior, N. Lorente, T. Frederiksen, A. Garcia and M. Brandbyge, Comput. Phys. Commun. 212, 8 (2017)
N. Papior, T. Gunst, D. Stradi and M. Brandbyge, Phys. Chem. Chem. Phys. 18, 1025 (2016)