Subharmonic gap structures and Josephson effect in MgB2/Nb micro-constrictions

Filippo Giubileo, Marco Aprili, Fabrizio Bobba +3

Superconducting micro-constrictions between Nb tips and high quality MgB${}_2$ pellets have been realized by means of a point-contact inset, driven by a micrometric screw. Measurem…