Toward room-temperature nanoscale skyrmions in ultrathin films

Abstract

Breaking the dilemma between small size and room temperature stability is a necessary prerequisite for skyrmion-based information technology. Here we demonstrate by means of rate theory and an atomistic spin Hamiltonian that the stability of isolated skyrmions in ultrathin ferromagnetic films can be enhanced by the concerted variation of magnetic interactions while keeping the skyrmion size unchanged. We predict film systems where the lifetime of sub-10 nm skyrmions can reach years at ambient conditions. The long lifetime of such small skyrmions is due to exceptionally large Arrhenius pre-exponential and the stabilizing effect of the energy barrier is insignificant at room temperature. A dramatic increase in the pre-exponential is achieved thanks to softening of magnon modes of the skyrmion, thereby increasing the entropy of the skyrmion with respect to the transition state for collapse. Increasing the number of skyrmion deformation modes should be a guiding principle for the realization of nanoscale, room-temperature stable skyrmions.

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Cited by in corpus (7)

• Strain-Driven Zero-Field Near-10 nm Skyrmions in Two-Dimensional van der Waals Heterostructures
• Prediction of stable nanoscale skyrmions in monolayer Fe${}_5$GeTe${}_2$
• Lifetime of skyrmions in discrete systems with infinitesimal lattice constant
• Thermal generation of droplet soliton in chiral magnet
• Effects of interlayer exchange on collapse mechanisms and stability of magnetic skyrmions
• Theory of magnetic field-stabilized compact skyrmions in thin film ferromagnets
• High-resolution tunneling spin transport characteristics of topologically distinct magnetic skyrmionic textures from theoretical calculations