Angle-dependent resonant dynamics of stripes and skyrmions in Re/Co/Pt multilayers

TL;DR

This study explores how angle-dependent resonant behaviors of skyrmions and stripe domains in Re/Co/Pt multilayers are influenced by Co thickness, revealing tunable magnetic properties crucial for spintronic and magnonic device development.

Contribution

It provides new insights into the static and dynamic properties of Re/Co/Pt multilayers, demonstrating angle-dependent skyrmion stabilization and resonant mode tunability based on material parameters.

Findings

Skyrmions can be stabilized without external fields at specific angles.

Resonant modes range from 2-35 GHz, depending on magnetic texture.

Effective damping decreases with increasing Co thickness.

Abstract

The dynamic behavior and stabilization of skyrmions in magnetic multilayers are critical for advancing spintronic and magnonic technologies. In our study, we investigate the static and dynamic properties of $[Re/Co(d_{Co})/Pt]_{20}$ multilayers with varying Co thicknesses $(6\text{-}24 \, \text{\r{A}})$, showcasing a transition from out-of-plane to in-plane magnetic anisotropy. Magnetization reversal leads to a transformation from labyrinth domains to skyrmion bubbles due to the interfacial Dzyaloshinskii-Moriya interaction (iDMI). Using angle-dependent imaging at remanence, we confirm that skyrmions can be stabilized without an external magnetic field at specific polar angles, with the stabilization angle increasing alongside Co thickness. Ferromagnetic resonance spectroscopy reveals four distinct resonant modes, including low-frequency $(2\text{-}18\text{GHz})$, high-frequency $(20\text{-}35 \, \text{GHz})$ modes, depending on the magnetization texture. The frequency range of these modes narrows with decreasing effective anisotropy and iDMI strength decreases in thicker Co layers in perpendicular configurations. Moreover, we observe a decrease in effective Gilbert damping with increasing Co thickness, highlighting the potential for efficient energy dissipation. These findings link between material properties and skyrmion dynamics directly and demonstrate tunable resonant modes for magnonic devices. By addressing both static and dynamic aspects, our work advances the development of next-generation spintronic and magnonic applications.