Linear relation between Heisenberg exchange and interfacial DzyaloshinskiiMoriya interaction in metal films
Hans T. Nembach, Justin M. Shaw, Mathias A. Weiler, Emilie M. Jue, Thomas J. Silva
Proposals for novel spin-orbitronic logic and memory devices are often dependent on assumptions as to how materials with large spin-orbit and ferromagnets interact when in contact. Such interactions give rise to a host of novel phenomena, such as spin-orbit torques, chiral spin- structures and chiral spin-torques. These chiral properties are related to the anti-symmetric exchange, also referred to as the interfacial Dzyaloshinskii-Moriya interaction (DMI). For numerous phenomena, the relative strengths of the symmetric Heisenberg exchange and the DMI is of great importance. Here, we use spin-wave spectroscopy (Brillouin light scattering) to directly determine the DMI vector for a series of Ni80Fe20/Pt samples and compare the DMI and the independently measured Heisenberg exchange. We find that the Ni80Fe20- thickness-dependencies of the Heisenberg exchange and the DMI are strongly correlated, consistent with the notion that the anti-symmetric and symmetric exchange essentially share the same underlying physics, as was originally proposed by Moriya. While of significant fundamental importance, this result also leads us to a deeper understanding of DMI and how it could be optimized for spin-orbitronic applications.
, Shaw, J.
, Weiler, M.
, Jue, E.
and Silva, T.
Linear relation between Heisenberg exchange and interfacial Dzyaloshinskii–Moriya interaction in metal films, Nature Physics, [online], https://doi.org/10.1038/nphys3418
(Accessed April 11, 2021)