High quality superconductor-barrier interfaces are critical for Josephson tunnel junctions. The authors show that such interfaces can be achieved in Mg B2 /insulator/Pb trilayer junctions using Mg B2 films grown by hybrid physical-chemical vapor deposition and with barriers formed at elevated temperatures. The junctions show clear Josephson tunneling characteristics with high Jc (∼3 kA cm2), high Ic RN products (∼1.9 meV), and the expected Ic (B) pattern. The observed π gap is small (2.0 meV) and the gap is large (7.4 meV), in agreement with theoretical predictions and indicating that the superconducting property of Mg B2 is not degraded at the Mg B2 -insulator interface.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)