2009/04/18 by Qing‐Feng Sun, Qing-feng Sun, X. C. Xie +1 · 3 citations
Materials Science · Physics and Astronomy · #Andreev reflection #Condensed matter physics #Conductance #Filling factor #Geometry #Graphene #Graphene nanoribbons #Graphene research and applications #Magnetic field #Materials science #Nanotechnology #Physics #Plateau (mathematics) #Quantum and electron transport phenomena #Quantum mechanics #Quantum tunnelling #Ribbon #Superconductivity #Surface and Thin Film Phenomena #Zigzag #cond-mat.mes-hall
paper · pdf · doi:10.1088/0953-8984/21/34/344204
published as J. Phys. Condens. Matter 21, 344204 (2009) · 15 pages, 9 figures
arxiv created 2009/04/18 · openalex publication_date 2009/07/27 · arxiv updated 2015/05/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the electron transport through a graphene nanoribbon-superconductor junction. Both zigzag and armchair edge graphene nanoribbons are considered, and the effects of the magnetic field and disorder on the transport property are investigated. By using the tight-binding model and the non-equilibrium Green's function method, the expressions of the current, conductance, normal tunneling coefficient and Andreev reflection coefficient are obtained. For a clean system and at zero magnetic field, the linear conductance increases approximately in a linear fashion with the on-site energy. In the presence of a magnetic field and a moderate disorder, the linear conductance exhibits plateau structures for both armchair and zigzag edges. The plateau values increase with the width of the graphene ribbon. With a wide sample width, a saturated plateau value of |ν|e(2)/h emerges at the filling factor ν. For a small filling factor, the conductance can reach the saturated value at a small width, but for a high filling factor it requires to have a quite wide sample width to reach the saturated value. In particular, the Andreev reflection coefficient is always at 0.5 after reaching the saturated value, independent of any system parameters. In addition, we also consider the finite bias case, in which the Andreev reflection coefficient and normal tunneling coefficient are studied.