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arXiv · 1105.2600

Josephson Current through a Planar Junction of Graphene

Yositake Takane·Ken-Ichiro Imura
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Abstract

Josephson effect in a planar graphene junction is studied by assuming that the coupling of a graphene sheet and two superconductors deposited on its top is described by a tunneling Hamiltonian. This model properly takes account of the proximity effect characteristic to a planar junction, and allows us to treat monolayer and bilayer cases in a parallel manner. Applying a quasiclassical Green's function approach to it we analyze the Josephson critical current $I_{\rm c}$ in a short-junction limit. As a characteristic feature of the planar junction we find that $I_{\rm c}$ is a concave function of temperature at the strong coupling limit while it crosses over to a convex function with decreasing the coupling strength. We also find different chemical-potential dependences of $I_{\rm c}$ in the monolayer and bilayer cases.

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Yositake Takane, Ken-Ichiro Imura. 2011-05-13. Josephson Current through a Planar Junction of Graphene. https://doi.org/10.1143/jpsj.80.043702

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