Oscillating decorated interfaces in parametrically driven systems

Macroscopic systems forced by the temporal modulation of their parameters exhibit complex interfaces between symmetric states. Here we investigate the origin of the transition from a flat to an oscillating decorated interface. Based on a model that describes a magnetic plane under the influence of an oscillating magnetic field and an extended Josephson junction under the influence of an alternating current, we derive a simple model that accounts for the interface dynamics. Analytically this model allows us to reveal that this transition is a parametric resonance between the frequencies of interface modes and the forcing. Numerical simulations of magnetic systems, extended Josephson junctions, and our simplified model show quite good agreement.