Thickness dependence of the interfacial Dzyaloshinskii–Moriya interaction in inversion symmetry broken systems

• Published in: Nature communications Vol. 6; no. 1; p. 7635
• Main Authors: Cho, Jaehun, Kim, Nam-Hui, Lee, Sukmock, Kim, June-Seo, Lavrijsen, Reinoud, Solignac, Aurelie, Yin, Yuxiang, Han, Dong-Soo, van Hoof, Niels J. J., Swagten, Henk J. M., Koopmans, Bert, You, Chun-Yeol
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08-07-2015; Nature Publishing Group; Nature Pub. Group
• Subjects: 140/125; 639/766/119/1001; 639/766/119/2793; 639/766/25; 639/766/483/1139; Humanities and Social Sciences; multidisciplinary; Physics; Science; Science (multidisciplinary); Ferromagnetism; Quantum mechanics; Applied physics; Spintronics
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms8635

In magnetic multilayer systems, a large spin-orbit coupling at the interface between heavy metals and ferromagnets can lead to intriguing phenomena such as the perpendicular magnetic anisotropy, the spin Hall effect, the Rashba effect, and especially the interfacial Dzyaloshinskii–Moriya (IDM) interaction. This interfacial nature of the IDM interaction has been recently revisited because of its scientific and technological potential. Here we demonstrate an experimental technique to straightforwardly observe the IDM interaction, namely Brillouin light scattering. The non-reciprocal spin wave dispersions, systematically measured by Brillouin light scattering, allow not only the determination of the IDM energy densities beyond the regime of perpendicular magnetization but also the revelation of the inverse proportionality with the thickness of the magnetic layer, which is a clear signature of the interfacial nature. Altogether, our experimental and theoretical approaches involving double time Green’s function methods open up possibilities for exploring magnetic hybrid structures for engineering the IDM interaction.
Spin-orbit effects at heavy metal/ferromagnet interfaces can give rise to the Dzyaloshinskii-Moriya interaction, promoting chiral magnetization textures applicable in thin film devices. Here, the authors use Brillouin light scattering to study the dependence of this interaction on film thickness.