Theoretical seminar | 13 April 2022

ITMO University
Stability and lifetime of topological magnetic structures. Continuous versus discrete lattice models.

The topological stabilization of chiral magnetic structures is discussed on the example of a two-dimensional magnetic skyrmion. The lifetime of a skyrmion is calculated based on the harmonic transition state theory. Localized magnetic models and models of itinerant magnetism are considered. A scaling theory has been developed for the lattice magnetic model. Using scaling relations derived from the continuous micromagnetic description, the parameters of the Hamiltonian corresponding to the exchange, anisotropy, and Dzyaloshinskii-Moriya interaction are chosen in such a way as to keep the energy of the skyrmion relative to the ground ferromagnetic state and its size unchanged. The number of magnetic moments included in the calculations reaches more than twenty millions. The evolution of the lifetime during the transition from a discrete to a continuous model, which reflects the "topological protection", is shown.

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