title: Ground state search, hysteretic behaviour, and reversal mechanism of skyrmionic textures in confined helimagnetic nanostructures.
abstract: Magnetic skyrmions have the potential to provide solutions for low-power, high-density data storage and processing. One of the major challenges in developing skyrmion-based devices is the skyrmions' magnetic stability in confined helimagnetic nanostructures. Through a systematic study of equilibrium states, using a full three-dimensional micromagnetic model including demagnetisation effects, we demonstrate that skyrmionic textures are the lowest energy states in helimagnetic thin film nanostructures at zero external magnetic field and in absence of magnetocrystalline anisotropy. We also report the regions of metastability for non-ground state equilibrium configurations. We show that bistable skyrmionic textures undergo hysteretic behaviour between two energetically equivalent skyrmionic states with different core orientation, even in absence of both magnetocrystalline and demagnetisation-based shape anisotropies, suggesting the existence of Dzyaloshinskii-Moriya-based shape anisotropy. Finally, we show that the skyrmionic texture core reversal dynamics is facilitated by the Bloch point occurrence and propagation.
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Marijan
authors.initials: M
authors.lastname: Beg
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Carey
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Cortés-Ortuño
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Vousden
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Marc-Antonio
authors.initials: MA
authors.lastname: Bisotti
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Albert
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Dmitri
authors.initials: D
authors.lastname: Chernyshenko
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Hovorka
authors.affiliation: SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Stamps
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Hans
authors.initials: H
authors.lastname: Fangohr