Driven damped pendulum — phase portrait and Poincaré section
θ = 0.000 ω = 0.000
The Josephson junction maps exactly to a driven damped pendulum: d²θ/dt² + (1/q)dθ/dt + sin θ = A cos(Ωt). For certain drive amplitudes A, the system enters chaos. Left panel: phase portrait (θ vs dθ/dt). Right panel: Poincaré section — a strange attractor emerges in the chaotic regime.