Phase Effect in Taming Nonautonomous Chaos by Weak Harmonic Perturbations

Abstract
An additional weak harmonic forcing is added to the Duffing equation, and its ability of suppressing chaos is analyzed in the global parameter space. It is found that the phase difference between the two sinusoidal forces plays a very important role in suppressing chaos. A new type of intermittency characterized by periodic appearance of regular and chaotic motions, called the breathing effect in this Letter, is observed when the two harmonic forces deviate slightly from resonance.