Coherent transport and electron interference in cuprate superconductor/graphene junctions
Abstract
Proximity-induced superconductivity is particularly interesting in graphene. Among other reasons, because that effect can be externally controlled by tuning the Fermi energy (and vector) via electrical gating. For example, using high-temperature superconducting YBa2Cu3O7/graphene planar junctions, we recently demonstrated gate-controlled superconducting electron interferences that allow modulating the Andreev reflection at the superconductor/graphene interface via Klein tunneling of electron/hole pairs. Here we will discuss new experiments in the same type of junctions, in which a different type of interferences -this time controlled by the bias voltage- are observed which are due to geometrical resonances and coherent propagation of electron/hole pairs across a graphene channel. This is substantiated by the relationship of the oscillations period and the graphene channel length (up to hundreds on nm), as well as by numerical simulations of the device conductance -which reproduce both the observed resonances and the background conductance.
Work supported by the ERC Grant 647100, ANR Grants ANR-15-CE24-0008-01 and ANR-17-CE30-0018-04,and COST Action CA16218 ``NanoCoHybri''.- Publication:
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APS March Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..MARF09014P