Title :
Characteristics of bi-crystal grain boundary junctions with different tilt angles for digital circuit applications
Author :
Gun Yong Sung ; Jeong Dae Suh ; Kwang Yong Kang ; Jun-Sik Hwang ; Soon-Gil Yoon ; Moon Chul Lee ; Soon Gul Lee
Author_Institution :
Electron. & Telecommun. Res. Inst., Daejeon, South Korea
fDate :
6/1/1999 12:00:00 AM
Abstract :
We have characterized bi-crystal grain boundary junctions with various tilt angles, i.e., 24/spl deg/, 30/spl deg/, 36.8/spl deg/, and 45/spl deg/ for digital applications. A simple rapid single-flux-quantum (RSFQ) logic circuit has been fabricated using a single layer high-T/sub c/ superconducting YBa/sub 2/Cu/sub 3/O/sub 7-x/ (YBCO) thin film structure with 4 bi-crystal grain boundary Josephson junctions. The circuit includes one readout superconducting quantum interference devices (SQUID) and one storage SQUID. We have focussed upon the readout SQUID properties, including J/sub c/, R/sub n/A, and I/sub c/R/sub n/, as a function of the tilt angles of the grain boundary junctions. The 24/spl deg/-tilt grain boundary junctions were the best candidates for the simple digital circuits among the bi-crystal grain boundary junctions of the tilt angle from 24/spl deg/ through 45/spl deg/. The response of the readout SQUID was demonstrated by an input signal through the storage SQUID at 82 K.
Keywords :
Josephson effect; SQUIDs; barium compounds; bicrystals; grain boundaries; high-temperature superconductors; superconducting logic circuits; superconducting thin films; yttrium compounds; 82 K; RSFQ logic circuit; SQUID; YBCO thin film; YBa/sub 2/Cu/sub 3/O/sub 7/; bicrystal grain boundary Josephson junction; digital circuit; high-T/sub c/ superconductor; tilt angle; Grain boundaries; Josephson junctions; Logic circuits; SQUIDs; Superconducting devices; Superconducting epitaxial layers; Superconducting logic circuits; Superconducting thin films; Thin film circuits; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
