Self-action effects in the propagation of surface magnetostatic wave pulses in a magnonic crystal–dielectric–metal structure

Problem formulating. It would be interesting to analyze the evolution of spin-waves self-action effects in MCs in the conditions when Bragg’s resonances form in the segments of dispersion in which the Lighthill criterion for modulation stabilityis observed.  Goal. This study aims at analysis of this problem for pulses of surface magnetostatic waves propagating in the magnonic crystal–dielectric–metal (MC–D–M) structure.

Result. It is shown that for microwave pulse at the pump frequency f there appears frequency interval ∆F in which the Lighthill criterion holds for the modulation instability evolution. It is shown for pulses with a carrier frequency f within ∆F and duration τ < τ* (parametric instability evolution time), the self-action effects may lead to the formation of SMSW solitons only when Bragg’s resonance frequencies are outside frequency interval ∆F. The presence of a subwavelength surface structure does not hamper the evolution of self-action effects leading to the formation of soliton-like pulses in the anomalous dispersion region in the MC–D–M structure.

Practical meaning. The possibility of using the layered structure of a magnon crystal − dielectric − metal as an effective controlled waveguide medium for the formation of soliton-like pulses of spin waves signal processing devices.