A strategy for the design of skyrmion racetrack memories

Abstract

Magnetic storage based on racetrack memory is very promising for the design of ultra-dense, low-cost and low-power storage technology. Information can be coded in a magnetic region between two domain walls or, as predicted recently, in topological magnetic objects known as skyrmions. Here, we show the technological advantages and limitations of using Bloch and Neel skyrmions manipulated by spin current generated within the ferromagnet or via the spin-Hall effect arising from a non-magnetic heavy metal underlayer. We found that the Neel skyrmion moved by the spin-Hall effect is a very promising strategy for technological implementation of the next generation of skyrmion racetrack memories (zero field, high thermal stability, and ultra-dense storage). We employed micromagnetics reinforced with an analytical formulation of skyrmion dynamics that we developed from the Thiele equation. We identified that the excitation, at high currents, of a breathing mode of the skyrmion limits the maximal velocity of the memory.

References in corpus (4)

• Spontaneous Skyrmion Ground States in Magnetic Metals
• Theory of current-driven motion of Skyrmions and spirals in helical magnets
• Spin-torque switching: Fokker-Planck rate calculation
• Influence of the Dzyaloshinskii-Moriya interaction on the spin-torque diode effect

Cited by in corpus (9)

• Emergent Phenomena Induced by Spin-Orbit Coupling at Surfaces and Interfaces
• Magnetic Skyrmion Bundles and Their Current-Driven Dynamics
• Stabilization and current-induced motion of antiskyrmion in the presence of anisotropic Dzyaloshinskii-Moriya interaction
• Deterministic Generation and Guided Motion of Magnetic Skyrmions by Focused He${}^{+}$-Ion Irradiation
• Spintronics, from giant magnetoresistance to magnetic skyrmions and topological insulators
• Skyrmion ratchet propagation: Utilizing the skyrmion Hall effect in AC racetrack storage devices
• Skyrmion pinning by disk-shaped defects
• Pinning of Helimagnetic Phase Transitions in Zn-Substituted Skyrmion Host Cu${}_2$OSeO${}_3$
• From the spin eigenmodes of isolated Néel skyrmions to the magnonic bands of a skyrmionic crystal: a micromagnetic study as a function of the strength of both the interfacial Dzyaloshinskii-Moriya and the exchange constants