Title :
Properties of multilevel ramp edge junctions and SQUIDs with laser-ablated SrTiO/sub 3/ barriers
Author :
Laibowitz, R.B. ; Sun, J.Z. ; Foglietti, V. ; Koch, R.H. ; Altman, R.A. ; Gallagher, W.J.
Author_Institution :
IBM Thomas J. Watson Res. Center, Yorktown Heights, NY, USA
fDate :
6/1/1995 12:00:00 AM
Abstract :
We have fabricated junctions and DC SQUIDs using laser ablation for both the YBCO electrodes and the thin SrTiO/sub 3/ (STO) barrier regions in a variety of device configurations. These SQUIDs operate reliably at 77 K and preliminary results on a limited number of devices show that they store reasonably well for periods in excess of one year, and exhibit only small changes with repeated cycles (/spl sim/10) between room temperature and 77 K. Noise measurements made using bias reversing on a SQUID (92 pH) at 77 K give a white noise of about 15 /spl mu//spl Phi//sub 0///spl radic/Hz and a 1/f upturn at about 0.2 Hz.<>
Keywords :
1/f noise; Josephson effect; SQUIDs; barium compounds; critical current density (superconductivity); high-temperature superconductors; pulsed laser deposition; strontium compounds; superconducting device noise; superconducting device reliability; superconducting device testing; white noise; yttrium compounds; 1/f upturn; 77 K; DC SQUIDs; I-V curves; SrTiO/sub 3/; SrTiO/sub 3/ barriers; YBa/sub 2/Cu/sub 3/O/sub 7/-SrTiO/sub 3/; YBaCuO electrodes; bias reversing; critical current density; laser ablation; multilevel ramp edge junctions; noise power spectrum; reliable operation; repeated cycling; white noise; Electrodes; Fabrication; Laser ablation; Optical pulses; Pulsed laser deposition; SQUIDs; Substrates; Superconducting films; Temperature; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
