Peak Effect, Melting, and Transport in Skyrmion Crystals

Abstract

We numerically examine the transport of skyrmions driven over weak random quenched disorder using a modified Thiele approach that includes the thermal softening of skyrmion pairwise interactions introduced by Wang et al., Phys. Rev. Appl. 18, 044024 (2022). The depinning transition is elastic at low temperatures but becomes plastic with a reduced threshold at higher temperatures due to the competition between thermal creep and thermal softening, indicating a temperature-induced order to disorder transition into a glass state. The resulting non-monotonic critical depinning forces and crossing of the velocity-force curves are similar to what is observed in the peak effect for type-II superconducting vortex lattices, where the softening of vortex-vortex interactions with temperature leads to an order-disorder transition. For low skyrmion densities the peak effect is absent since the system is always in a disordered state. We map the dynamical phase transition as a function of temperature, density, drive, and materials parameters, and show that the signatures are similar to those of the superconducting peak effect. Our results are consistent with recent experiments.

arXiv comment12 pages, 15 postscript figures

References in corpus (33)

• Skyrmion Lattice in a Chiral Magnet
• Advances in the Physics of Magnetic Skyrmions and Perspective for Technology
• Observation of room temperature magnetic skyrmions and their current-driven dynamics in ultrathin Co films
• Direct Observation of the Skyrmion Hall Effect
• Emergent electrodynamics of skyrmions in a chiral magnet
• Skyrmion Hall Effect Revealed by Direct Time-Resolved X-Ray Microscopy
• Theory of current-driven motion of Skyrmions and spirals in helical magnets
• Collective Transport: From Superconductors to Earthquakes
• Room-temperature current-induced generation and motion of sub-100nm skyrmions
• Thermal skyrmion diffusion applied in probabilistic computing
• Nonequilibrium Dynamic Phase Diagram for Vortex Lattices
• Particle model for skyrmions in metallic chiral magnets: dynamics, pinning and creep
• Depinning and nonequilibrium dynamic phases of particle assemblies driven over random and ordered substrates: a review
• Moving glass theory of driven lattices with disorder
• Dynamic instabilities and memory effects in vortex matter
• Statics and Dynamics of Skyrmions Interacting with Pinning: A Review
• Metastability and Glassy Behavior of a Driven Flux-Line Lattice
• Nonequilibrium Steady States of Driven Periodic Media
• Current-Driven Skyrmion Dynamics and Drive-Dependent Skyrmion Hall Effect in an Ultrathin Film
• Melting a skyrmion lattice topologically: through the hexatic phase to a skyrmion liquid
• Moving Wigner Glasses and Smectics: Dynamics of Disordered Wigner Crystals
• Topology-Dependent Brownian Gyromotion of a Single Skyrmion
• STM Imaging of Flux Line Arrangements in the Peak Effect Regime
• Peak Effect, Fishtail Effect and Plateau Effect : The Reentrant Amorphization of Vortex Matter in 2H-NbSe_2
• Thermal Creep and the Skyrmion Hall Angle in Driven Skyrmion Crystals
• Peak Effect in Superconductors: Melting of Larkin Domains
• Theory of magnetic skyrmion glass
• Two step disordering of the vortex lattice across the peak effect in a weakly pinned Type II superconductor, Co0.0075NbSe2
• Magnetic skyrmion interactions in the micromagnetic framework
• Skyrmion relaxation dynamics in the presence of quenched disorder
• Nonlinear Transport, Dynamic Ordering, and Clustering for Driven Skyrmions on Random Pinning
• Skyrmion lattice creep at ultra-low current densities
• Late stages in the ordering of magnetic skyrmion lattices