Thermodynamics of the quasiperiodic parameter set at the borderline of chaos: Experimental results

A periodically driven relaxation-oscillator circuit is used to study experimentally the multifractal structure of the quasiperiodic parameter set on the critical line. The experimental data provide evidence of a phase transition in the thermodynamic free energy q({τ}). The experimental thermodynamics compares well with that of the sine circle map and provides strong evidence for universality in the parameter scaling at the borderline of chaos.