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 σ and the average bandwidth in the chaotic regime scales with a universal number $\beta$, both in good agreement with theoretical predictions. Measured values of other universal numbers are reported.

• Received 13 May 1982

DOI:https://doi.org/10.1103/PhysRevLett.49.1888