Magnus-Induced Ratchet Effects for Skyrmions Interacting with Asymmetric Substrates

Abstract

When a particle is driven with an ac force over an asymmetric potential, it can undergo a ratchet effect that produces a net dc motion of the particle. Ratchet effects have been observed in numerous systems such as superconducting vortices on asymmetric pinning substrates. Skyrmions, stable topological spin textures with particle-like properties, have many similarities to vortices but their behavior is strongly influenced by non-disspative effects arising from a Magnus term in their equation of motion. We show using numerical simulations that pronounced ratchet effects can occur for ac driven skyrmions moving over asymmetric quasi-one-dimensional substrates. We find a new type of ratchet effect called a Magnus-induced transverse ratchet that arises when the ac driving force is applied perpendicular rather than parallel to the asymmetry direction of the substrate. This transverse ratchet effect only occurs when the Magnus term is finite, and the threshold ac amplitude needed to induce it decreases as the Magnus term becomes more prominent. Ratcheting skyrmions follow ordered orbits in which the net displacement parallel to the substrate asymmetry direction is quantized. Skyrmion ratchets represent a new ac current-based method for controlling skyrmion positions and motion for spintronic applications.

7 pages, 7 figures

References in corpus (10)

• Blowing Magnetic Skyrmion Bubbles
• Theory of current-driven motion of Skyrmions and spirals in helical magnets
• A new class of chiral materials hosting magnetic skyrmions beyond room temperature
• Highly Improved Staggered Quarks on the Lattice, with Applications to Charm Physics
• Thermally Driven Ratchet Motion of Skyrmion Microcrystal and Topological Magnon Hall Effect
• Capturing of a Magnetic Skyrmion with a Hole
• Current-Driven Dynamics of Skyrmions Stabilized in MnSi Nanowires Revealed by Topological Hall Effect
• Quantized Transport for a Skyrmion Moving on a Two-Dimensional Periodic Substrate
• Reversible Vortex Ratchet Effects and Ordering in Superconductors with Simple Asymmetric Potential Arrays
• A mechanism to pin skyrmions in chiral magnets

Cited by in corpus (36)

• Statics and Dynamics of Skyrmions Interacting with Pinning: A Review
• Manipulation of Magnetic Skyrmions by Superconducting Vortices in Ferromagnet-Superconductor Heterostructures
• Skyrmion ratchet propagation: Utilizing the skyrmion Hall effect in AC racetrack storage devices
• The effect of the Magnus force on skyrmion relaxation dynamics
• Reversible Vector Ratchets for Skyrmion Systems
• Skyrmion Ratchet in Funnel Geometries
• Skyrmion ratchet effect driven by a biharmonic force
• Transport of underdamped active particles in ratchet potentials
• Dynamics of Magnus Dominated Particle Clusters, Collisions, Pinning and Ratchets
• Topological dynamics and current-induced motion in a skyrmion lattice
• 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
• Controlling skyrmion helicity via engineered Dzyaloshinskii-Moriya interactions
• Dynamics of magnetic skyrmion clusters driven by spin-polarized current with a spatially varied polarization
• Chiral Skyrmions Interacting with Chiral Flowers
• Shapiro Spikes and Negative Mobility for Skyrmion Motion on Quasi-One-Dimensional Periodic Substrates
• Clogging, Diode and Collective Effects of Skyrmions in Funnel Geometries
• Fundamental Theory of Current-Induced Motion of Magnetic Skyrmions
• Shapiro Steps and Nonlinear Skyrmion Hall Angles For dc and ac Driven Skyrmions on a Two Dimensional Periodic Substrate
• Effects of hydrodynamic interactions on rectified transport of self-propelled particles
• Particle-like skyrmions interacting with a funnel obstacle
• Spontaneous Skyrmion Conformal Lattice and Transverse Motion During dc and ac Compression
• Traps for pinning and scattering of antiferromagnetic skyrmions via magnetic properties engineering
• Dynamics and Nonmonotonic Drag for Individually Driven Skyrmions
• Magnetic Skyrmion Transport in a Nanotrack With Spatially Varying Damping and Non-adiabatic Torque
• Directed Motion of Liquid Crystal Skyrmions With Oscillating Fields
• Magnus Induced Diode Effect for Skyrmions in Channels with Periodic Potentials
• Collective Dynamics and Defect Generation for Wigner Crystal Ratchets
• Skyrmion Pinball and Directed Motion on Obstacle Arrays
• Chiral Edge Currents for ac Driven Skyrmions in Confined Pinning Geometries
• Transformation of a cellular skyrmion to polyomino-like structures
• Topological quantization of the flow of magnetic skyrmions driven by a ratchet-like potential under thermal fluctuations
• Ultrafast ratchet dynamics of skyrmion by defect engineering under gigahertz magnetic fields
• Magnetic Field Effects and Transverse Ratchets in Charge Lattices Coupled to Asymmetric Substrates
• Nonhermitian adiabatic perturbation theory of topological quantization of the average velocity of a magnetic skyrmion under thermal fluctuations