Universal Scaling and Chaotic Behavior of a Josephson-Junction Analog

Abstract

Power spectra and phase-space trajectories for a sine-wave-driven Josephson-junction analog are measured, showing period-doubling bifurcations and transition to chaos. The total noise power follows closely a universal power law with a critical exponent \ensuremath{\sigma} and the average bandwidth in the chaotic regime scales with a universal number $\ensuremath{\beta}$, both in good agreement with theoretical predictions. Measured values of other universal numbers are reported.