We report on some unusual behavior of the measured current-voltage characteristics (CVC) in artificially prepared two-dimensional unshunted array of overdamped Nb- AlOx -Nb Josephson junctions. The obtained nonlinear CVC are found to exhibit a pronounced (and practically temperature independent) crossover at some current Icr = (1/2 ΒC-1) I C from a resistance R dominated state with VR =R I 2 - IC2 below Icr to a capacitance C dominated state with VC = /4eC I-IC above Icr. The origin of the observed behavior is discussed within a single-plaquette approximation assuming the conventional resistively shunted junction model with a finite capacitance and the Ambegaokar-Baratoff relation for the critical current of the single junction. © 2010 American Institute of Physics.
Sergeenkov, S., Rivera, V. A. G., Marega, E., & Araujo-Moreira, F. M. (2010). Universal resistance capacitance crossover in current-voltage characteristics for unshunted array of overdamped Nb- AlO<inf>x</inf>-Nb Josephson junctions. Journal of Applied Physics. https://doi.org/10.1063/1.3407566