Tunneling spectroscopy of graphene nanodevices coupled to large-gap superconductors

Joel I-Jan Wang; Landry Bretheau; Daniel Rodan-Legrain; Riccardo Pisoni; Kenji Watanabe; Takashi Taniguchi; Pablo Jarillo-Herrero

doi:10.1103/PhysRevB.98.121411

Tunneling spectroscopy of graphene nanodevices coupled to large-gap superconductors

Joel I-Jan Wang, Landry Bretheau, Daniel Rodan-Legrain, Riccardo Pisoni, Kenji Watanabe, Takashi Taniguchi, Pablo Jarillo-Herrero

DOI 10.1103/PhysRevB.98.121411 · Physical Review B

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

We performed tunneling spectroscopy measurements of graphene coupled to niobium/niobium-nitride superconducting electrodes. Due to the proximity effect, the graphene density of states depends on the phase difference between the superconductors and exhibits a hard induced gap at zero phase, consistent with a continuum of Andreev bound states. At energies larger than the superconducting gap, we observed phase-dependent energy levels displaying the Coulomb blockade effect, which are interpreted as arising from spurious quantum dots, presumably embedded in the heterostructures and coupled to the proximitized graphene.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
NbN Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	9	Pressure not reported	unknown
Nb Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	7	Pressure not reported	unknown
Ti Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	0.4	Pressure not reported	unknown