Use of 2-dimensional arrays to determine the uniformity of Josephson junctions

The linewidths of phase-locked, oscillating arrays of high temperature superconducting Josephson junctions have been used to estimate such statistical information for several junction processes using a fitting process to simulate results. Statistical data from arrays consisting of several hundred to many thousand junctions operating, and at least partially phase locked, at 77K are being used to characterize and improve junction processes. Spreads on critical currents for three different processes; step edge, edge SNS and electron-beam defined nanobridges, have ranged from +or-3% to 15% (l sigma ) and on normal state resistances from +or-2% to 11%.< >