Slow steady flow of a skyrmion lattice in a confined geometry probed by resistance narrow-band noise

Abstract

Using resistance fluctuation spectroscopy, we observe current-induced narrow-band noise (NBN) in the magnetic skyrmion-lattice phase of micrometer-sized MnSi. The NBN appears only when electric-current density exceeds a threshold value, indicating that the current-driven motion of the skyrmion lattice triggers the NBN. The observed NBN frequency is 10-10${}^4$ Hz at $\sim$10${}^9$ A/m${}^2$, implying a skyrmion steady flow velocity of 1-100 $\mu$m/s, 3-5 orders of magnitude slower than previously reported. The temperature evolution of the NBN frequency suggests that the steady flow entails thermally activated processes, which are most likely due to skyrmion creation and annihilation at the sample edges. This scenario is qualitatively supported by our numerical simulations considering boundary effects, which reveals that the edges limit the steady flow of skyrmions, especially at low temperatures. We discuss a mechanism that dramatically slows the skyrmion steady flow in a microfabricated specimen.

5 pages, 4 figures

References in corpus (3)

• Skyrmion Hall Effect Revealed by Direct Time-Resolved X-Ray Microscopy
• Theory of current-driven motion of Skyrmions and spirals in helical magnets
• Current-induced viscoelastic topological unwinding of metastable skyrmion strings

Cited by in corpus (13)

• Statics and Dynamics of Skyrmions Interacting with Pinning: A Review
• Laminar and transiently disordered dynamics of a magnetic skyrmion pipe flow
• Nonlinear Dynamics, Avalanches and Noise for Driven Wigner Crystals
• Dynamics and Nonmonotonic Drag for Individually Driven Skyrmions
• Commensuration Effects on Skyrmion Hall Angle and Drag for Manipulation of Skyrmions on Two-Dimensional Periodic Substrates
• Skyrmion Dynamics and Transverse Mobility: Skyrmion Hall Angle Reversal on 2D Periodic Substrates with dc and Biharmonic ac Drives
• Late stages in the ordering of magnetic skyrmion lattices
• Skyrmion Pinball and Directed Motion on Obstacle Arrays
• Noise and Thermal Depinning of Wigner Crystals
• Current-induced sliding motion in a helimagnet MnAu${}_2$
• Sliding Dynamics of Current-Driven Skyrmion Crystal and Helix in Chiral Magnets
• Fluctuations and Pinning for Individually Manipulated Skyrmions
• Driven Superconducting Vortex Dynamics in Systems with Two-Fold Anisotropy in the Presence of Pinning