Spin-Orbit-Enhanced Robustness of Supercurrent in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>Graphene</mml:mi><mml:mo>/</mml:mo><mml:msub><mml:mrow><mml:mi>WS</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math> Josephson Junctions
Taro Wakamura, Nian-Jheng Wu, A. D. Chepelianskii, S. Guéron, Mauro Och, M. Ferrier, Takashi Taniguchi, Kenji Watanabe, Cecilia Mattevi, H. Bouchiat
Abstract
We demonstrate the enhanced robustness of the supercurrent through graphene-based Josephson junctions in which strong spin-orbit interactions (SOIs) are induced. We compare the persistence of a supercurrent at high out-of-plane magnetic fields between Josephson junctions with graphene on hexagonal boron-nitride and graphene on WS_{2}, where strong SOIs are induced via the proximity effect. We find that in the shortest junctions both systems display signatures of induced superconductivity, characterized by a suppressed differential resistance at a low current, in magnetic fields up to 1 T. In longer junctions, however, only graphene on WS_{2} exhibits induced superconductivity features in such high magnetic fields, and they even persist up to 7 T. We argue that these robust superconducting signatures arise from quasiballistic edge states stabilized by the strong SOIs induced in graphene by WS_{2}.