Title :
Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7//MgO/Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/ edge Josephson junctions
Author :
Robertazzi, R.P. ; Koch, R.H. ; Laibowitz, R.B. ; Gallagher, W.J.
Author_Institution :
IBM Thomas J. Watson Res. Center, Yorktown Heights, NY, USA
fDate :
3/1/1993 12:00:00 AM
Abstract :
Josephson edge junctions have been fabricated using thin sputtered films of MgO (8-32 AA) to produce a weak connection between high-T/sub c/ electrodes. The current-voltage characteristics of these junctions can be well modeled by the resistively shunted junction (RSJ) equation, and they possess excellent Josephson properties, exhibiting strong magnetic field modulation and microwave response at 10 and 100 GHz up to 85 K. The best high temperature (T>70 K) operation has been obtained with devices which have critical current densities in excess of 10/sup 5/ A/cm/sup 2/ at 4.2 K, and junction critical current resistance products I/sub c/R/sub n/ equivalent to 0.10 mV at 83 K. Experiments indicate that improvements in device quality are expected as the base electrode junction surface is improved. Preliminary results indicate that the cyclability of these junctions is good.<>
Keywords :
Josephson effect; barium compounds; critical current density (superconductivity); high-temperature superconductors; magnesium compounds; superconducting junction devices; yttrium compounds; 10 GHz; 100 GHz; 85 K; HTSC; YBa/sub 2/Cu/sub 3/O/sub 7/-MgO-YBa/sub 2/Cu/sub 3/O/sub 7/ junctions; critical current densities; critical current resistance products; current-voltage characteristics; cyclability; edge Josephson junctions; microwave response; resistive shunted junction equation; strong magnetic field modulation; weak connection; weak links; Current-voltage characteristics; Electrodes; Equations; Magnetic fields; Magnetic films; Magnetic modulators; Magnetic properties; Microwave devices; Surface resistance; Temperature;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
