Sandwich-type MgB2/MgO/MgB2 Josephson junctions with Au or MgB2 interconnection were fabricated using hybrid physical-chemical vapor deposited MgB2 thin films and RF-magnetron-sputtered MgO barrier. The junctions show properties similar to those in high-JcNb junctions with Jc up to 275kA/cm 2 at 4 K, which remains nonzero up to 40 K. Critical current modulations by applied magnetic field and constant voltage steps under microwave radiation were observed. Combined with the larger energy gaps in MgB 2 than in Nb, the junctions presented here allow simple MgB 2 digital circuits to work over 20 K or with a clock speed above 1 THz.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)