Experimental Observation of Ultrashort Hyperchaotic Dark Multisoliton Complexes in a Magnonic Active Ring Resonator.

We report on the self-generation of ultrashort hyperchaotic dark multisoliton sequences with two positive large Lyapunov exponents in an active ring resonator consisting of a multifunctional L-shaped magnonic waveguide and a saturable amplifier. The irregular magnonic waveguide supports the converting of backward volume magnetostatic spin waves with negative dispersion to magnetostatic surface spin waves with positive dispersion that is accompanied by a transition from four-wave to three-wave nonlinear spin-wave interactions. Each multisoliton complex consists of four dark parametric pulses containing the soliton trains of four dark incoherent spin-wave envelope solitons possessing a subnanosecond duration.