Coupled skyrmion breathing modes in synthetic ferri- and antiferromagnets

TL;DR

This paper uses micromagnetic simulations to explore GHz-range resonance modes of skyrmions in synthetic ferri- and antiferromagnetic trilayers, revealing mode dependencies on interlayer coupling and potential for skyrmion sensing.

Contribution

It introduces a detailed analysis of skyrmion breathing modes in multilayer structures, highlighting the effects of coupling strength and mode hybridization, which is novel in the context of synthetic ferri- and antiferromagnets.

Findings

Resonance modes depend systematically on interlayer coupling strength.

Identification of pure in-phase and anti-phase breathing modes.

Potential for skyrmion detection and characterization in multilayer stacks.

Abstract

We present micromagnetic simulations of the dynamic GHz-range resonance modes of skyrmions excited by either out-of-plane ac magnetic fields or spin torques in prototypical synthetic ferri- and antiferromagnetic trilayer structures. The observed features in the calculated power spectra exhibit a systematic dependence on the coupling strength between the individual magnetic layers and are related to pure in-phase and anti-phase breathing modes as well as to hybridizations of breathing and spin-wave modes that are characteristic for the considered circular-shaped geometry. The experimental detection of these resonant oscillation modes may provide a means for skyrmion sensing applications and for the general characterization of skyrmion states in multilayer stacks with antiferromagnetic interlayer exchange coupling.