Gyrotropic resonance of individual N\'eel skyrmions in Ir/Fe/Co/Pt multilayers

TL;DR

This study investigates the magnetization dynamics of room-temperature Ne9el skyrmions in multilayer films, revealing a gyrotropic resonance mode influenced by multilayer interactions, with implications for nanoscale device applications.

Contribution

It provides the first detailed spectroscopic analysis of gyrotropic resonance in Ne9el skyrmions within multilayers, combining experiments, simulations, and analytical models.

Findings

Identification of a robust gyrotropic resonance mode in microwave spectra.

Resonance frequencies are significantly renormalized to lower values due to multilayer interactions.

Insights into the spatiotemporal dynamics of topological spin structures for device applications.

Abstract

Magnetic skyrmions are nanoscale spin structures recently discovered at room temperature (RT) in multilayer films. Employing their novel topological properties towards exciting technological prospects requires a mechanistic understanding of the excitation and relaxation mechanisms governing their stability and dynamics. Here we report on the magnetization dynamics of RT N\'eel skyrmions in Ir/Fe/Co/Pt multilayer films. We observe a ubiquitous excitation mode in the microwave absorption spectrum, arising from the gyrotropic resonance of topological skyrmions, and robust over a wide range of temperatures and sample compositions. A combination of simulations and analytical calculations establish that the spectrum is shaped by the interplay of interlayer and interfacial magnetic interactions unique to multilayers, yielding skyrmion resonances strongly renormalized to lower frequencies. Our work provides fundamental spectroscopic insights on the spatiotemporal dynamics of topological spin structures, and crucial directions towards their functionalization in nanoscale devices.