Enhancement of dynamical coupling in artificial spin-ice systems by incorporating perpendicularly magnetized ferromagnetic matrix

TL;DR

This paper demonstrates how embedding artificial spin-ice in a perpendicularly magnetized matrix significantly enhances magnonic coupling, enabling advanced reconfigurable magnonic devices with tunable interactions.

Contribution

It introduces a novel hybrid spin-ice system with enhanced magnon-magnon coupling via interface exchange interactions and vertex reconfiguration.

Findings

Strong magnon-magnon coupling observed with anticrossing gap.

Coupling strength increased by nearly 40% through vertex magnetization reconfiguration.

Hybrid system exhibits a rich, tunable spin-wave spectrum.

Abstract

Artificial spin-ice systems, consisting of arrays of interacting ferromagnetic nanoelements, offer a versatile platform for reconfigurable magnonics with potential in GHz logic and neuromorphic computing. However, weak dipolar coupling between nanoelements severely limits their functionality. We numerically demonstrate a rich spin-wave spectrum in a square spin-ice structure immersed in a perpendicularly magnetized ferromagnetic matrix, which is different from a single spin-ice system. We observe a strong magnon-magnon coupling between the bulk second-order mode of the nanoelements and the fundamental mode of the matrix, supported by a pronounced anticrossing frequency gap. We show that, in addition to the dipolar coupling, exchange interactions at the nanoelement-matrix interface play a crucial role in this hybridization. Furthermore, the strength of the coupling can be enhanced by almost 40% just by reconfiguring the magnetization at the vertices from low-energy to high-energy monopole states. These results open the way to exploit artificial spin-ice systems for magnonic applications, taking advantage of the strong coupling and vertex-dependent dynamics.