Phase-sensitive evidence for the sign-reversal s+- symmetry of the order parameter in an iron-pnictide superconductor using Nb/Ba1-xNaxFe2As2 Josephson junctions

A. A. Kalenyuk, A. Pagliero, E. A. Borodianskyi +2

Josephson current between two superconductors provides a phase sensitive tool for probing their pairing symmetries. Here we fabricate and study experimentally high-quality Josephso…