Massive dynamics of skyrmions in ferrimagnetic films
Dmitry A. Garanin, Eugene M. Chudnovsky
TLDR
Skyrmions in ferrimagnets exhibit massive, gyroscopic dynamics, unlike massless ferromagnet behavior, leading to detectable cyclotron resonance.
Key contributions
- Ferrimagnetic skyrmions show massive dynamics due to multiple magnetic sublattices, unlike massless ferromagnetic ones.
- This massive dynamics results in gyroscopic motion and skyrmion cyclotron resonance, excitable by microwaves.
- Analyzes motion and resonant oscillations of skyrmions/lattices in two-sublattice transition-metal/rare-earth systems.
- Skyrmion dynamics and excitation spectrum change significantly near the angular momentum compensation point.
Why it matters
This paper reveals the unique massive dynamics of skyrmions in ferrimagnets, explaining their gyroscopic motion and cyclotron resonance. These findings, particularly the changes near the angular momentum compensation point, offer new avenues for experimental detection and manipulation of skyrmions.
Original Abstract
Deformations of skyrmions arising from the presence of more than one magnetic sublattice lead to their massive dynamics in ferrimagnets as compared to the massless dynamics in 2D ferromagnets. This results in the gyroscopic motion of skyrmions, which manifests as skyrmion cyclotron resonance that can be excited by microwaves or spin currents. We investigate analytically and numerically the motion and resonant oscillations of individual skyrmions and skyrmion lattices in the presence of dissipation in a two-sublattice transition-metal -- rare-earth (TM/RE) system. The focus is on the dependence of the skyrmion dynamics on the RE concentration. Parameters of the CoGd ferrimagnet are utilized in the numerical work. The massive dynamics of skyrmions in ferrimagnets, as well as the spectrum of their excitations, undergo significant changes near the angular momentum compensation point, which should not be difficult to detect in experiments.
📬 Weekly AI Paper Digest
Get the top 10 AI/ML arXiv papers from the week — summarized, scored, and delivered to your inbox every Monday.