Swing casting boost for confined domain wall breathing

A steady breathing mode excitation of the confined domain wall under dc is a candidate signal source in future telecommunication devices. The breathing mode exhibits a non-linear response to dc with a threshold. Before driving the breathing mode, if we resonantly swing the domain wall by ac, the domain wall is expected to be cast to a breathing mode even below the threshold dc. To examine the effect of "swing casting", we investigate the resonant mode under ac. We show that overdamped, underdamped, chaotic, and periodic running modes emerge depending on the applied ac amplitude. Furthermore, we demonstrate that swing casting achieves the steady breathing mode excitation down to one quarter of the threshold dc.