Proximity Effects in Superconductor--Graphene Junctions

ORAL

Abstract

Superconducting proximity effects are of particular interest in graphene: because of its band structure, an unconventional (specular) Andreev reflection is expected [1]. In this context, high-Tc superconductor-graphene junctions are especially attractive. In these, the size of the superconducting energy-gap may exceed the graphene doping inhomogeneities around the Dirac point, which should favor the observation of the specular Andreev reflection. Yet, the fabrication of high-Tc superconductor-graphene junctions is challenging: the usual growth and lithography processes in both materials are incompatible. We report here on a fabrication method that allow us to fabricate planar cuprate superconductor-graphene junctions, which we characterize via conductance spectroscopy. We analyze the features in the conductance spectra as a function of graphene doping, and discuss them in the framework of the Andreev reflection. [1] C. W. J. Beenakker. Phys. Rev. Lett. 97, 067007 (2006)

*work supported by Labex Nanosaclay

Authors

  • Fabian A. Cuellar

    • Unite Mixte de Physique and Universite Paris-Sud, Palaiseau, France
  • David Perconte

    • Unite Mixte de Physique and Universite Paris-Sud, Palaiseau, France
  • Marie-Blandine Martin

    • Unite Mixte de Physique and Universite Paris-Sud, Palaiseau, France
  • Bruno Dlubak

    • Unite Mixte de Physique and Universite Paris-Sud, Palaiseau, France
  • Maelis Piquemail

    • Unite Mixte de Physique and Universite Paris-Sud, Palaiseau, France
  • Rozenn Bernard

    • Unite Mixte de Physique and Universite Paris-Sud, Palaiseau, France
  • Juan Trastoy

    • Unite Mixte de Physique and Universite Paris-Sud, Palaiseau, France
  • Constance Moreau-Luchaire

    • Unite Mixte de Physique and Universite Paris-Sud, Palaiseau, France
  • Pierre Seneor

    • Unite Mixte de Physique and Universite Paris-Sud, Palaiseau, France
  • Javier E. Villegas

    • Unite Mixte de Physique and Universite Paris-Sud, Palaiseau, France
  • Piran Kidambi

    • Department of Engineering, University of Cambridge, Cambridge, United Kingdom
  • Stephan Hofmann

    • Department of Engineering, University of Cambridge, Cambridge, United Kingdom
  • John Robertson

    • Department of Engineering, University of Cambridge, Cambridge, United Kingdom