Enhanced skyrmion stability due to exchange frustration

[en] Skyrmions are localized, topologically non-trivial spin structures which have raised high hopes for future spintronic applications. A key issue is skyrmion stability with respect to annihilation into the ferromagnetic state. Energy barriers for this collapse have been calculated taking only nearest neighbor exchange interactions into account. Here, we demonstrate that exchange interactions beyond nearest neighbors can be essential to describe stability of skyrmionic spin structures. We focus on the prototypical film system Pd/Fe/Ir(111) and demonstrate that an effective nearest-neighbor exchange or micromagnetic model can only account for equilibrium properties such as the skyrmion profile or the zero temperature phase diagram. However, energy barriers and critical fields of skyrmion collapse as well as skyrmion lifetimes are drastically underestimated since the energy of the transition state cannot be accurately described. Antiskyrmions are not even metastable. Our work shows that frustration of exchange interactions is a route towards enhanced skyrmion stability even in systems with a ferromagnetic ground state.

Disciplines :

Physics

Author, co-author :

von Malottki, Stephan

Dupé, Bertrand ; Université de Liège - ULiège > Département de physique > Physique des matériaux et nanostructures

Bessarab, Pavel F.

Delin, A.

Heinze, Stefan

Language :

English

Title :

Enhanced skyrmion stability due to exchange frustration

Publication date :

2017

Journal title :

Scientific Reports

eISSN :

2045-2322

Publisher :

Nature Publishing Group, London, United Kingdom

Volume :

Issue :

Pages :

12299

Peer reviewed :

Peer Reviewed verified by ORBi

Additional URL :

http://www.nature.com/articles/s41598-017-12525-x

Available on ORBi :

since 15 January 2020

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