Journal of Computational Electronics

, Volume 12, Issue 2, pp 63–75 | Cite as

Transport through quantum spin Hall insulator/metal junctions in graphene ribbons

  • Elsa Prada
  • Georgo Metalidis


Quantum spin Hall insulator/metal interfaces are formed in graphene ribbons with intrinsic spin-orbit coupling by selectively doping two regions creating a potential step. For a clean graphene ribbon, the transmission of the topological edge states through a n-n or p-p junction is perfect irrespective of the ribbon termination, width, and potential step parameters due to the orthogonality of incoming and outgoing edge channels. This is shown numerically for an arbitrary crystallographic orientation of the ribbon and proven analytically for zigzag and metallic armchair boundary conditions. In disordered ribbons, the orthogonality between left- and right-movers is in general destroyed and backscattering sets in. However, transmission approaches one by increasing the ribbon’s width, even in the presence of strong edge roughness.


Graphene ribbons Quantum spin Hall effect pn Junctions Quantum transport 



E.P. acknowledges the support of the CSIC JAE-Doc program and the Spanish Ministry of Science and Innovation through Grant No. FIS2009-08744.


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Copyright information

© Springer Science+Business Media New York 2012

Authors and Affiliations

  1. 1.Instituto de Ciencia de Materiales de MadridCSICMadridSpain
  2. 2.Institut für Theoretische Festkörperphysik and DFG-Center for Functional NanostructuresKarlsruhe Institute of Technology (KIT)KarlsruheGermany

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