Path sampling for lifetimes of metastable magnetic skyrmions and direct comparison with Kramers' method

Abstract

We perform a direct comparison between Kramers' method in many dimensions -- i.e., Langer's theory -- adapted to magnetic spin systems, and a path sampling method in the form of forward flux sampling, as a means to compute collapse rates of metastable magnetic skyrmions. We show that a good agreement is obtained between the two methods. We report variations of the attempt frequency associated with skyrmion collapse by three to four orders of magnitude when varying the applied magnetic field by 5$\%$ of the exchange strength, which confirms the existence of a strong entropic contribution to the lifetime of skyrmions. This demonstrates that in complex systems, the knowledge of the rate prefactor, in addition to the internal energy barrier, is essential in order to properly estimate a lifetime.

arXiv comment5 pages, 5 figures (main text), 8 pages including supplemental material

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Cited by in corpus (14)

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• Atomistic perspective of long lifetimes of small skyrmions at room temperature
• Spontaneous creation and annihilation dynamics and strain-limited stability of magnetic skyrmions
• Dzyaloshinskii-Moriya interaction induced by an ultrashort electromagnetic pulse: Application to coherent (anti)ferromagnetic skyrmion nucleation
• A micromagnetic theory of skyrmion lifetime in ultrathin ferromagnetic films
• The lifetime of micron scale topological chiral magnetic states with atomic resolution
• Stability of Long-lived Antiskyrmions in Mn-Pt-Sn Material
• Skyrmions as quasiparticles: free energy and entropy
• Quantifying the thermal stability in perpendicularly magnetized ferromagnetic nanodisks with forward flux sampling
• Theory of magnetic field-stabilized compact skyrmions in thin film ferromagnets
• Eigenmodes of magnetic skyrmion lattices
• Anisotropy-dependent decay of room temperature metastable skyrmions and a nascent double-$q$ spin texture in Co${}_8$Zn${}_9$Mn${}_3$
• Single-stage direct Langevin dynamic simulations of transitions over arbitrary high energy barriers: Concept of the energy-dependent temperature
• Strongly enhanced lifetime of higher-order bimerons and antibimerons