Theory of antiskyrmions in magnets

• Published in: Nature communications 2016-01, Vol.7 (1), p.10542-10542, Article 10542
• Main Authors: Koshibae, Wataru, Nagaosa, Naoto
• Format: Article
• Language: English
• Subjects: 639/301/119/997; 639/766/419; Approximation; Energy; Humanities and Social Sciences; multidisciplinary; Phase transitions; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms10542

Skyrmions and antiskyrmions are swirling topological magnetic textures realized as emergent particles in magnets. A skyrmion is stabilized by the Dzyaloshinskii–Moriya interaction in chiral magnets and/or a dipolar interaction in thin film magnets, which prefer the twist of the magnetic moments. Here we show by a numerical simulation of the Landau–Lifshitz–Gilbert equation that pairs of skyrmions and antiskyrmions are created from the helix state as the magnetic field is increased. Antiskyrmions are unstable and disappear immediately in chiral magnets, whereas they are metastable and survive in dipolar magnets. The collision between a skyrmion and an antiskyrmion in a dipolar magnet is also studied. It is found that the collision depends on their relative direction, and the pair annihilation occurs in some cases and only the antiskyrmion is destroyed in the other cases. These results indicate that the antiskyrmion offers a unique opportunity to study particles and antiparticles in condensed-matter systems. Skyrmions are swirling topological magnetic textures that behave as if they were particles. Here, the authors present numerical simulations that describe the creation and destruction of these spin vortices in both chiral and dipolar magnets, and show what happens when skyrmions and antiskyrmions collide.