Jump to main content
Jump to site search

Issue 6, 2018
Previous Article Next Article

Supercurrent and multiple Andreev reflections in micrometer-long ballistic graphene Josephson junctions

Author affiliations

Abstract

Ballistic Josephson junctions are predicted to support a number of exotic physics processess, providing an ideal system to inject the supercurrent in the quantum Hall regime. Herein, we demonstrate electrical transport measurements on ballistic superconductor–graphene–superconductor junctions by contacting graphene to niobium with a junction length up to 1.5 μm. Hexagonal boron nitride encapsulation and one-dimensional edge contacts guarantee high-quality graphene Josephson junctions with a mean free path of several micrometers and record-low contact resistance. Transports in normal states including the observation of Fabry–Pérot oscillations and Sharvin resistance conclusively witness the ballistic propagation in the junctions. The critical current density JC is over one order of magnitude larger than that of the previously reported junctions. Away from the charge neutrality point, the ICRN product (IC is the critical current and RN the normal state resistance of junction) is nearly a constant, independent of carrier density n, which agrees well with the theory for ballistic Josephson junctions. Multiple Andreev reflections up to the third order are observed for the first time by measuring the differential resistance in the micrometer-long ballistic graphene Josephson junctions.

Graphical abstract: Supercurrent and multiple Andreev reflections in micrometer-long ballistic graphene Josephson junctions

Back to tab navigation

Supplementary files

Publication details

The article was received on 10 Aug 2017, accepted on 09 Jan 2018 and first published on 09 Jan 2018


Article type: Paper
DOI: 10.1039/C7NR05904C
Citation: Nanoscale, 2018,10, 3020-3025
  •   Request permissions

    Supercurrent and multiple Andreev reflections in micrometer-long ballistic graphene Josephson junctions

    M. Zhu, M. Ben Shalom, A. Mishchsenko, V. Fal'ko, K. Novoselov and A. Geim, Nanoscale, 2018, 10, 3020
    DOI: 10.1039/C7NR05904C

Search articles by author

Spotlight

Advertisements