Toward nonlinear magnonics: Intensity-dependent spin-wave switching in insulating side-coupled magnetic stripes

TLDR

The authors propose an analytical theory based on coupled Ginzburg–Landau equations that predicts a geometry design reducing the power required for all‑magnonic switching. They investigate collective nonlinear spin‑wave dynamics using Brillouin light scattering and micromagnetic/finite‑element simulations, and develop a coupled Ginzburg–Landau model to describe magnetodipolar coupling and power‑efficient switching. Experiments show intensity‑dependent power exchange, mode transformation, and differential phase shift between adjacent stripes, with calculations matching observations, demonstrating that the spin‑wave coupling mechanism enables nonlinear magnonic circuits and all‑magnonic computing.

Abstract

We demonstrate that the nonlinear spin-wave transport in two laterally parallel magnetic stripes exhibit the intensity-dependent power exchange between the adjacent spin-wave channels. By the means of Brillouin light scattering technique, we investigate collective nonlinear spin-wave dynamics in the presence of magnetodipolar coupling. The nonlinear intensity-dependent effect reveals itself in the spin-wave mode transformation and differential nonlinear spin-wave phase shift in each adjacent magnetic stripe. The proposed analytical theory, based on the coupled Ginzburg-Landau equations, predicts the geometry design involving the reduction of power requirement to the all-magnonic switching. A very good agreement between calculation and experiment was found. In addition, a micromagnetic and finite-element approach has been independently used to study the nonlinear behavior of spin waves in adjacent stripes and the nonlinear transformation of spatial profiles of spin-wave modes. Our results show that the proposed spin-wave coupling mechanism provides the basis for nonlinear magnonic circuits and opens the perspectives for all-magnonic computing architecture.