English

Entropy-limited topological protection of skyrmions

Mesoscale and Nanoscale Physics 2024-02-02 v2

Abstract

Magnetic skyrmions are topologically protected whirls that decay through singular magnetic configurations known as Bloch points. We have used Lorentz transmission electron microscopy to infer the energetics associated with the topological decay of magnetic skyrmions far from equilibrium in the chiral magnet Fe1x_{1-x}Cox_xSi. We observed that the life time τ\tau of the skyrmions depends exponentially on temperature, ττ0eΔE/kBT\tau \sim \tau_0 \, e^{\Delta E/k_B T}. The prefactor τ0\tau_0 of this Arrhenius law changes by more than 30 orders of magnitude for small changes of magnetic field reflecting a substantial reduction of the life time 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.

Keywords

Cite

@article{arxiv.1705.01719,
  title  = {Entropy-limited topological protection of skyrmions},
  author = {J. Wild and T. N. G. Meier and S. Pöllath and M. Kronseder and A. Bauer and A. Chacon and M. Halder and M. Schowalter and A. Rosenauer and J. Zweck and J. Müller and A. Rosch and C. Pfleiderer and C. H. Back},
  journal= {arXiv preprint arXiv:1705.01719},
  year   = {2024}
}

Comments

6 pages, 4 figures, 5 pages supplement, 4 figures supplement