Topological spin waves in the atomic-scale magnetic skyrmion crystal. (19th April 2016)

• Record Type: Journal Article
• Authors: Roldán-Molina, A; Nunez, A S; Fernández-Rossier, J
• Is Part Of: New journal of physics. Volume 18:Number 4(2016:Apr.)
• Publication Date: 2016-04-19
• Subjects: topological magnonics -- skyrmion lattice -- spin waves; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/18/4/045015
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: We study the spin waves of the triangular skyrmion crystal that emerges in a two-dimensional spin lattice model as a result of the competition between Heisenberg exchange, Dzyalonshinkii–Moriya interactions, Zeeman coupling and uniaxial anisotropy. The calculated spin wave bands have a finite Berry curvature that, in some cases, leads to non-zero Chern numbers, making this system topologically distinct from conventional magnonic systems. We compute the edge spin-waves, expected from the bulk-boundary correspondence principle, and show that they are chiral, which makes them immune to elastic backscattering. Our results illustrate how topological phases can occur in self-generated emergent superlattices at the mesoscale.