Time-dependent density-functional theory simulation of local currents in pristine and single-defect zigzag graphene nanoribbons

Journal Article · Thu Jul 21 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4959088· OSTI ID:22597764

He, Shenglai; Russakoff, Arthur; Li, Yonghui; Varga, Kálmán ^[1]

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1. Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)

The spatial current distribution in H-terminated zigzag graphene nanoribbons (ZGNRs) under electrical bias is investigated using time-dependent density-functional theory solved on a real-space grid. A projected complex absorbing potential is used to minimize the effect of reflection at simulation cell boundary. The calculations show that the current flows mainly along the edge atoms in the hydrogen terminated pristine ZGNRs. When a vacancy is introduced to the ZGNRs, loop currents emerge at the ribbon edge due to electrons hopping between carbon atoms of the same sublattice. The loop currents hinder the flow of the edge current, explaining the poor electric conductance observed in recent experiments.

• OSTI ID: 22597764
• Journal Information: Journal of Applied Physics, Vol. 120, Issue 3; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMS
COMPUTERIZED SIMULATION
CURRENTS
DEFECTS
DENSITY FUNCTIONAL METHOD
ELECTRONS
GRAPHENE
GRIDS
HYDROGEN
NANOSTRUCTURES
TIME DEPENDENCE
VACANCIES