Vk. Kaplunenko et al., 600 GHZ RESONANT MODE IN A PARALLEL ARRAY OF JOSEPHSON TUNNEL-JUNCTIONS CONNECTED BY SUPERCONDUCTING MICROSTRIP LINES, Journal of applied physics, 76(5), 1994, pp. 3172-3176
The high frequency properties of the one-dimensional transmission line
consisting of a parallel array of resistively shunted Josephson tunne
l junctions have been studied in the limit of relatively low damping w
here this nonlinear system exhibits new and interesting phenomena. Her
e we report on experimental and numerical investigations of a resonant
step observed at a voltage corresponding to 600 GHz in the dc current
-voltage characteristic of a parallel array of 20 identical small NbAl
2O3Nb Josephson junctions interconnected by short sections of supercon
ducting microstrip line. The junctions are mutually phase locked due t
o collective interaction with the line sections excited close to the h
alf wavelength resonance. The phase locking range can be adjusted by m
eans of an external dc magnetic field and the step size varies periodi
cally with the magnetic field. The largest step corresponds to a super
conducting phase difference of pi between neighboring junctions.