Title :
Interface-engineered Josephson junctions optimized for high JC
Author :
Shimakage, Hisashi ; Ono, Ronald H. ; Vale, Leila R. ; Wang, Zhen
Author_Institution :
Commun. Res. Lab., Kansai Adv. Res. Centre, Kobe, Japan
fDate :
6/1/2001 12:00:00 AM
Abstract :
High-temperature superconducting interface-engineered junctions were fabricated using YBa2Cu3O7-δ on LaAlO3 (LAO) and sapphire substrates. We report on the improvements in the electrical characteristics by junction narrowing. Originally, the 2-μm-wide junctions had high critical current densities of 1.2 × 106 A/cm at 4.0 K and showed wide junction effects. Narrowing the junctions to below a micrometer reduced the wide junction effect over a large range of temperatures and the junctions had characteristic voltages of 5.16 mV at 4.0 K. The magnetic-field modulation of the critical current was also more ideal after narrowing. Furthermore, we show that interface engineered junctions on sapphire substrates have similar characteristics to those on LAO
Keywords :
barium compounds; critical current density (superconductivity); high-temperature superconductors; superconducting junction devices; yttrium compounds; 2 micron; 4.0 K; 5.16 mV; LaAlO3; YBa2Cu3O7-δ; YBa2Cu3O7; critical current densities; high-temperature superconductors; interface-engineered Josephson junctions; junction narrowing; magnetic-field modulation; wide junction effects; Annealing; Critical current; Critical current density; High temperature superconductors; Josephson junctions; Optical films; Reproducibility of results; Superconducting microwave devices; Voltage; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
