Shear Banding, Intermittency, Jamming and Dynamic Phases for Skyrmions in Inhomogeneous Pinning Arrays

Abstract

We examine driven skyrmion dynamics in systems with inhomogeneous pinning where a strip of strong pinning coexists with a region containing no pinning. For driving parallel to the strip, we find that the initial skyrmion motion is confined to the unpinned region and the skyrmion Hall angle is zero. At larger drives, a transition occurs to a phase in which motion also appears within the pinned region, creating a shear band in the skyrmion velocity, while the skyrmion Hall angle is still zero. As the drive increases further, the flow becomes disordered and the skyrmion Hall angle increases with drive until saturating at the highest drives when the system transitions into a moving crystal phase. The different dynamic phases are associated with velocity and density gradients across the pinning boundaries. We map out the dynamic phases as a function of pinning strength, skyrmion density, and Magnus force strength, and correlate the phase boundaries with features in the velocity-force curves and changes in the local and global ordering of the skyrmion structure. For large Magnus forces, the shear banding instability is replaced by large scale intermittent flow in the pinned region accompanied by simultaneous motion perpendicular to the direction of the drive, which appears as oscillations in the transport curves. We also examine the case of a drive applied perpendicular to the strip, where we find a jamming effect in which the skyrmion flow is blocked by skyrmion-skyrmion interactions until the drive is large enough to induce plastic flow.

19 pages, 31 figures

References in corpus (17)

• Advances in the Physics of Magnetic Skyrmions and Perspective for Technology
• Skyrmion Hall Effect Revealed by Direct Time-Resolved X-Ray Microscopy
• Theory of current-driven motion of Skyrmions and spirals in helical magnets
• Thermally Driven Ratchet Motion of Skyrmion Microcrystal and Topological Magnon Hall Effect
• Capturing of a Magnetic Skyrmion with a Hole
• Real-Space Berry Phases - Skyrmion Soccer
• Direct measurements of growing amorphous order and non-monotonic dynamic correlations in a colloidal glass-former
• Quantized Transport for a Skyrmion Moving on a Two-Dimensional Periodic Substrate
• A mechanism to pin skyrmions in chiral magnets
• On the origin of the reversed vortex ratchet motion
• Asymmetric weak-pinning superconducting channels: vortex ratchets
• Active Microrheology, Hall Effect, and Jamming in Chiral Fluids
• Commensurability Effects at Nonmatching Fields for Vortices in Diluted Periodic Pinning Arrays
• Skyrmion relaxation dynamics in the presence of quenched disorder
• Pinning, Ordering, and Dynamics of Vortices in Conformal Crystal and Gradient Pinning Arrays
• Slow steady flow of a skyrmion lattice in a confined geometry probed by resistance narrow-band noise
• Topical Review on Skyrmions and Hall Transport

Cited by in corpus (10)

• Laminar and transiently disordered dynamics of a magnetic skyrmion pipe flow
• Configurable pixelated skyrmions on nanoscale magnetic grids
• Guided Skyrmion Motion Along Pinning Array Interfaces
• Particle-like skyrmions interacting with a funnel obstacle
• Bimerons create bimerons: proliferation and aggregation induced by currents and magnetic fields
• Structural transition of skyrmion quasiparticles under compression
• Active Matter Shepherding and Clustering in Inhomogeneous Environments
• Late stages in the ordering of magnetic skyrmion lattices
• Operando Control of Skyrmion Density in a Lorentz Transmission Electron Microscope with Current Pulses
• Anti-Poiseuille Flow: Increased Vortex Velocity at Superconductor Edges