A. Laub et al., THE INFLUENCE OF THE CRITICAL-CURRENT SPREAD ON THE FREQUENCY LOCKINGOF JOSEPHSON-JUNCTIONS IN 2-DIMENSIONAL ARRAYS, Journal of applied physics, 83(10), 1998, pp. 5302-5306
Two-dimensional arrays of overdamped Josephson junctions under microwa
ve irradiation have been examined experimentally. We show that the sha
pe of the Shapiro steps in the current-voltage curve of the array is c
losely related to the critical current spread of the junctions and tha
t its dynamic resistance is closely related to the number of frequency
locked junctions which are visualized by low-temperature scanning ele
ctron microscopy. (C) 1998 American Institute of Physics.