Tunable Klein-like tunneling of high-temperature superconducting pairs into graphene

Abstract

Superconductivity can be induced in a normal material via the leakage of superconducting pairs of charge carriers from an adjacent superconductor. This so-called proximity effect is markedly influenced by graphene unique electronic structure, both in fundamental and technologically relevant ways. These include an unconventional form of the leakage mechanism the Andreev reflection and the potential of supercurrent modulation through electrical gating. Despite the interest of high-temperature superconductors in that context, realizations have been exclusively based on low-temperature ones. Here we demonstrate gate-tunable, high-temperature superconducting proximity effect in graphene. Notably, gating effects result from the perfect transmission of superconducting pairs across an energy barrier -a form of Klein tunneling, up to now observed only for non-superconducting carriers- and quantum interferences controlled by graphene doping. Interestingly, we find that this type of interferences become dominant without the need of ultra-clean graphene, in stark contrast to the case of low-temperature superconductors. These results pave the way to a new class of tunable, high-temperature Josephson devices based on large-scale graphene.

References in corpus (12)

• Chiral tunneling and the Klein paradox in graphene
• Andreev reflection and Klein tunneling in graphene
• Bipolar supercurrent in graphene
• Quantum interference and Klein tunneling in graphene heterojunctions
• Specular Andreev reflection in graphene
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• Josephson Current and Multiple Andreev Reflections in Graphene SNS Junctions
• Tunneling conductance of graphene NIS junctions
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• p-wave triggered superconductivity in single layer graphene on an electron-doped oxide superconductor
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Cited by in corpus (6)

• Andreev Reflection and Klein Tunneling in High-Temperature Superconductor/Graphene Junctions
• Superconducting proximity effect in $d$-wave cuprate/ graphene heterostructures
• Effects of discrete topology on quantum transport across a graphene $n-p-n$ junction: A quantum gravity analogue
• Disorder-dependent superconducting pairing symmetry in doped graphene
• Local characterization and engineering of proximitized correlated states in graphene-NbSe${}_2$ vertical heterostructures
• Coupling of Klein-Andreev Resonant States in Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+x}$-graphene-Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+x}$ Devices