Regensburg 2022 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 18: Spintronics
MA 18.4: Vortrag
Dienstag, 6. September 2022, 15:45–16:00, H47
Spin wave spectrum asymmetry from nonlocal chiral renormalization of gyromagnetic ratio — •Ivan Ado1,2 and Mikhail Titov2 — 1Institute for Theoretical Physics, Utrecht University, 3584 CC Utrecht, The Netherlands — 2Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands
We present a new potential source of the spin wave spectrum asymmetry in metallic and semiconducting magnets. Such an asymmetry is often used to experimentally measure the Dzyaloshinskii-Moriya interaction (DMI) strength using Brillouin light scattering (BLS). We argue that there exists an additional contribution to the asymmetry that originates in coupling between magnetic moments and charge carriers. Moreover, this contribution is sensitive to electron scattering by impurities and depends on the parameters of the electron diffusive motion. We address the corresponding mechanism as "nonlocal chiral renormalization of gyromagnetic ratio". We analyze it both microscopically and using symmetry arguments, for a prototypical 2D metallic ferromagnet. The resulting contribution to the asymmetry scales quadratically with the scattering time and thus can be particularly strong in sufficiently clean systems. We suggest that experimental measurements of DMI by means of BLS may be inaccurate if one does not take this effect into account.