Microwave resonances of magnetic skyrmions in thin film multilayers

Abstract

Non-collinear magnets exhibit a rich array of dynamic properties at microwave frequencies. They can host nanometre-scale topological textures known as skyrmions, whose spin resonances are expected to be highly sensitive to their local magnetic environment. Here, we report a magnetic resonance study of an [Ir/Fe/Co/Pt] multilayer hosting Néel skyrmions at room temperature. Experiments reveal two distinct resonances of the skyrmion phase during in-plane ac excitation, with frequencies between 6-12 GHz. Complementary micromagnetic simulations indicate that the net magnetic dipole moment rotates counterclockwise (CCW) during both resonances. The magnon probability distribution for the lower-frequency resonance is localised within isolated skyrmions, unlike the higher-frequency mode which principally originates from areas between skyrmions. However, the properties of both modes depend sensitively on the out-of-plane dipolar coupling, which is controlled via the ferromagnetic layer spacing in our heterostructures. The gyrations of stable isolated skyrmions reported in this room temperature study encourage the development of new material platforms and applications based on skyrmion resonances. Moreover, our material architecture enables the resonance spectra to be tuned, thus extending the functionality of such applications over a broadband frequency range.

19 pages, 5 figures

References in corpus (9)

• Additive interfacial chiral interaction in multilayers for stabilization of small individual skyrmion at room temperature
• Skyrmion Hall Effect Revealed by Direct Time-Resolved X-Ray Microscopy
• Magnon-skyrmion scattering in chiral magnets
• Microwave photovoltage and photoresistance effects in ferromagnetic microstrips
• Magnetoelectric Resonances and Predicted Microwave Diode Effect of Skyrmion Crystal in Multiferroic Chiral-Lattice Magnet
• Quantized spin excitations in a ferromagnetic microstrip from microwave photovoltage measurements
• Magnetization dynamics and its scattering mechanism in thin CoFeB films with interfacial anisotropy
• Stabilizing zero-field skyrmions in Ir/Fe/Co/Pt thin film multilayers by magnetic history control
• Tunable magnetization relaxation of Fe_{2}Cr_{1-x}Co_{x}Si half-metallic Heusler alloys by band structure engineering

Cited by in corpus (3)

• Skyrmion-Excited Spin Wave Fractal Network
• From the spin eigenmodes of isolated Néel skyrmions to the magnonic bands of a skyrmionic crystal: a micromagnetic study as a function of the strength of both the interfacial Dzyaloshinskii-Moriya and the exchange constants
• Strong Coupling between Propagating Magnons and High-order Gyrotropic Skyrmion Modes