Breathing Modes of Confined and Coupled Magnetic Skyrmions in Synthetic Ferrimagnet Multilayer Nanodots

Magnetic skyrmions have been demonstrated to exhibit internal microwave frequency excitations and possess intrinsic topological stability, particle‐like characteristics, low driving current density, and nanoscale dimensions, which make them promising candidates for neuromorphic computing and data storage. These magnetic entities are capable of existing in synthetic ferrimagnetic multilayers and exhibit unique dynamic behaviors in comparison to their ferromagnetic counterparts. Micromagnetic simulations are used to analyze the dynamic GHz‐range resonance modes of magnetic skyrmions generated by an out‐of‐plane AC magnetic field in circular‐shaped synthetic ferrimagnetic multilayers. In the circular geometry, hybridizations of breathing and spin‐wave modes are shown by the power spectra, which correlate with the coupling strength between magnetic layers. The influence of structural disorder and temperature effects on the breathing resonant modes of the magnetic skyrmions is further investigated in the power spectra of the system using micromagnetic simulations. Skyrmion sensing and a better understanding of skyrmionic states in general may both benefit from the experimental observation of these resonant oscillation modes in synthetic ferrimagnetic multilayer stacks having an antiferromagnetic interlayer exchange coupling.