Spin-transfer torque-driven motion, deformation, and instabilities of magnetic skyrmions at high currents

Abstract

In chiral magnets, localized topological magnetic whirls, magnetic skyrmions, can be moved by spin polarized electric currents. Upon increasing the current strength, with prospects for high-speed skyrmion motion for spintronics applications in mind, isolated skyrmions deform away from their typical circular shape. We analyze the influence of spin-transfer torques on the shape of a single skyrmion, including its stability upon adiabatically increasing the strength of the applied electric current. For rather compact skyrmions at uniaxial anisotropies well above the critical anisotropy for domain wall formation, we find for high current densities that the skyrmion assumes a non-circular shape with a tail, reminiscent of a shooting star. For larger and hence softer skyrmions close to the critical anisotropy, in turn, we observe a critical current density above which skyrmions become unstable. We show that above a second critical current density the shooting star solution can be recovered also for these skyrmions.

13 pages, 11 figures

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Cited by in corpus (13)

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• Fast current-induced skyrmion motion in synthetic antiferromagnets
• Geometry and Symmetry in Skyrmion Dynamics
• Skyrmion Dynamics in the Presence of Deformation
• Voltage-Controlled Skyrmionic Interconnect with Multiple Magnetic Information Carriers
• Current-induced H-shaped-skyrmion creation and their dynamics in the helical phase
• Current-Induced Dynamics of Chiral Magnetic Structures: Creation, Motion, and Applications
• Ultrafast manipulations of nanoscale skyrmioniums
• Response of the chiral soliton lattice to spin polarized currents
• Motion-induced inertial effects and topological phase transitions in skyrmion transport
• Elliptical skyrmions: theory and nucleation by a magnetic tip in an antiskyrmion-hosting material
• Inducing Skyrmion Flop Transitions in Co${}_8$Zn${}_8$Mn${}_4$ at Room Temperature
• Effects of interlayer Dzyaloshinskii-Moriya interaction on the shape and dynamics of magnetic twin-skyrmions