MAGNETIC-FIELD-INDUCED INTERMITTENCY IN SPIN-WAVE EXPERIMENTS

Chaotic behavior in spin-wave systems is usually observed with the variation of the driving parameter, namely, the incident microwave power. A variety of interesting phenomena can occur if one keeps the power fixed beyond the auto-oscillation threshold and varies another available parameter. We demonstrate this with X-band subsidiary-resonance experiments in an yttrium iron garnet (YIG) sphere with varying dc magnetic field. Besides period-doubling bifurcations, intermittent temporal bursting resulting from the collision of neighbouring period-I and chaotic attractors has been observed. These phenomena are qualitatively investigated in the light of the theory of crisis in dissipative systems due to Grebogi, Ott, Romeiras, and Yorke. In addition, for fixed magnetic field and varying microwave power, we observe that transient periods prior to auto-oscillation have a power-law dependence on the driving parameter, similarly to crisis-induced phenomena at higher power levels.