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Entropy-limited topological protection of skyrmions.

ABSTRACT: Magnetic skyrmions are topologically protected whirls that decay through singular magnetic configurations known as Bloch points. We used Lorentz transmission electron microscopy to infer the energetics associated with the topological decay of magnetic skyrmions far from equilibrium in the chiral magnet Fe_1-x Co _x Si. We observed that the lifetime τ of the skyrmions depends exponentially on temperature, [Formula: see text]. The prefactor τ₀ of this Arrhenius law changes by more than 30 orders of magnitude for small changes of the magnetic field, reflecting a substantial reduction of the lifetime of skyrmions by entropic effects and, thus, an extreme case of enthalpy-entropy compensation. Such compensation effects, being well known across many different scientific disciplines, affect topological transitions and, thus, topological protection on an unprecedented level.

SUBMITTER: Wild J

PROVIDER: S-EPMC5621974 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature

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Entropy-limited topological protection of skyrmions.

Wild Johannes J Meier Thomas N G TNG Pöllath Simon S Kronseder Matthias M Bauer Andreas A Chacon Alfonso A Halder Marco M Schowalter Marco M Rosenauer Andreas A Zweck Josef J Müller Jan J Rosch Achim A Pfleiderer Christian C Back Christian H CH

Science advances 20170929 9

Magnetic skyrmions are topologically protected whirls that decay through singular magnetic configurations known as Bloch points. We used Lorentz transmission electron microscopy to infer the energetics associated with the topological decay of magnetic skyrmions far from equilibrium in the chiral magnet Fe1-x Co x Si. We observed that the lifetime τ of the skyrmions depends exponentially on temperature, [Formula: see text]. The prefactor τ0 of this A ...[more]

PMID: 28975152

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