Chiral asymmetry of the spin-wave spectra in ultrathin magnetic films.

Phys Rev Lett

Department of Theoretical Physics, Budapest University of Technology and Economics, H1111 Budapest, Hungary.

Published: May 2009

We raise the possibility that the chiral degeneracy of the magnons in ultrathin films can be lifted due to the presence of Dzyaloshinskii-Moriya interactions. By using simple symmetry arguments, we discuss under which conditions such a chiral asymmetry occurs. We then perform relativistic first principles calculations for an Fe monolayer on W(110) and explicitly reveal the asymmetry of the spin-wave spectrum in the case of wave vectors parallel to the (001) direction. Furthermore, we quantitatively interpret our results in terms of a simplified spin model by using calculated Dzyaloshinskii-Moriya vectors. Our theoretical prediction should inspire experiments to explore the asymmetry of spin waves, with a particular emphasis on the possibility to measure the Dzyaloshinskii-Moriya interactions in ultrathin films.

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http://dx.doi.org/10.1103/PhysRevLett.102.207204DOI Listing

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