How to induce superconductivity in epitaxial graphene via remote proximity effect through an intercalated gold layer

• Published in: 2d materials Vol. 8; no. 1; pp. 15002 - 15013
• Main Authors: Mazaleyrat, Estelle, Vlaic, Sergio, Artaud, Alexandre, Magaud, Laurence, Vincent, Thomas, Cristina Gómez-Herrero, Ana, Lisi, Simone, Singh, Priyank, Bendiab, Nedjma, Guisset, Valérie, David, Philippe, Pons, Stéphane, Roditchev, Dimitri, Chapelier, Claude, Coraux, Johann
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.01.2021
• Subjects: angle-resolved photoemission spectroscopy; Condensed Matter; graphene; intercalation; Materials Science; Physics; Raman spectroscopy; scanning tunneling microscopy; scanning tunneling spectroscopy; superconductivity; scanning tunneling spectroscopy; superconductivity; intercalation; Raman spectroscopy; scanning tunneling microscopy; graphene; angle-resolved photoemission spectroscopy
• ISSN: 2053-1583; 2053-1583
• DOI: 10.1088/2053-1583/abb71f

Graphene holds promises for exploring exotic superconductivity with Dirac-like fermions. Making graphene a superconductor at large scales is however a long-lasting challenge. A possible solution relies on epitaxially-grown graphene, using a superconducting substrate. Such substrates are scarce, and usually destroy the Dirac character of the electronic band structure. Using electron diffraction (reflection high-energy, and low-energy), scanning tunneling microscopy and spectroscopy, atomic force microscopy, angle-resolved photoemission spectroscopy, Raman spectroscopy, and density functional theory calculations, we introduce a strategy to induce superconductivity in epitaxial graphene via a remote proximity effect, from the rhenium substrate through an intercalated gold layer. Weak graphene-Au interaction, contrasting with the strong undesired graphene-Re interaction, is demonstrated by a reduced graphene corrugation, an increased distance between graphene and the underlying metal, a linear electronic dispersion and a characteristic vibrational signature, both latter features revealing also a slight p doping of graphene. We also reveal that the main shortcoming of the intercalation approach to proximity superconductivity is the creation of a high density of point defects in graphene (1014 cm−2). Finally, we demonstrate remote proximity superconductivity in graphene/Au/Re(0001), at low temperature.