A Brillouin light scattering study of the spin-wave magnetic field dependence in a magnetic hybrid system made of an artificial spin-ice structure and a film underlayer

TL;DR

This study combines Brillouin light scattering and micromagnetic simulations to analyze how magnetic fields influence spin-wave spectra in a hybrid artificial spin-ice and permalloy film system, revealing mode coupling and potential for magnonic device applications.

Contribution

It introduces a combined experimental and simulation approach to identify and understand dynamic mode coupling in a novel hybrid magnetic structure.

Findings

Identification of spin-wave modes and their symmetry

Detection of dynamic coupling between modes

Implications for 3D magnonic device development

Abstract

We present a combined Brillouin light scattering and micromagnetic simulation investigation of the magnetic-field dependent spin-wave spectra in a hybrid structure made of permalloy (NiFe) artificial spin-ice (ASI) systems, composed of stadium-shaped nanoislands, deposited on the top of an unpatterned permalloy film with a nonmagnetic spacer layer. The thermal spin-wave spectra were recorded by Brillouin light scattering (BLS) as a function of the magnetic field applied along the symmetry direction of the ASI sample. Magneto-optic Kerr effect magnetometry was used to measure the hysteresis loops in the same orientation as the BLS measurements. The frequency and intensity of several spin-wave modes detected by BLS were measured as a function of the applied magnetic field. Micromagnetic simulations enabled us to identify the modes in terms of their frequency and spatial symmetry and to extract information about the existence and strength of the dynamic coupling, relevant only to a few modes of a given hybrid system. Using this approach, we suggest a way to understand if dynamic coupling between ASI and film modes is present or not, with interesting implications for the development of future three-dimensional magnonic applications and devices.