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Accueil du site > Séminaires > Séminaires 2020 > Magnetic skyrmions : from pure mathematics to quantitative physical predictions

Mardi 3 novembre, 2020 - 14:00

Magnetic skyrmions : from pure mathematics to quantitative physical predictions

Anne Bernand-Mantel (LPCNO-INSA) - en visio

par Revaz Ramazashvili - 3 novembre 2020

A skyrmion is a topologically nontrivial field configuration that locally minimizes an energy functional of a nonlinear field theory. Magnetic skyrmions consist of local swirls of spins. As topological solitons, they exhibit quasi-particle properties, including quantized topological charge. They are stabilized by the competition between interactions which favors parallel alignment of spins and energies which promotes their rotation. In this talk, we consider the case of an ultrathin ferromagnetic film where nanoscale skyrmions have recently attracted a lot of attention in the spintronic community [1]. I will describe the theory of magnetic skyrmions and present our recent result where calculus of variations and asymptotic analysis was used to prove the existence an predict the properties of magnetic skyrmions, taking into account for the first time the full non-local dipolar interaction [2].

[1] Perspective : Magnetic skyrmions—Overview of recent progress in an active research field K. Evershor-Sitte et al. JAP 124, 240901 (2018).

[2] Unraveling the role of dipolar versus Dzyaloshinskii-Moriya interactions in stabilizing compact magnetic skyrmions, A. Bernand-Mantel at al PRB 101, 045416 (2020).

Post-scriptum :

contact : R. Ramazashvili