Nature Communications (Apr 2023)

Dynamic self-organisation and pattern formation by magnon-polarons

  • M. Gidding,
  • T. Janssen,
  • C. S. Davies,
  • A. Kirilyuk

DOI
https://doi.org/10.1038/s41467-023-37919-6
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 6

Abstract

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Abstract Magnetic materials play a vital role in energy-efficient data storage technologies, combining very fast switching with long-term retention of information. However, it has been shown that, at very short time scales, magnetisation dynamics become chaotic due to internal instabilities, resulting in incoherent spin-wave excitations that ultimately destroy magnetic ordering. Here, contrary to expectations, we show that such chaos gives rise to a periodic pattern of reversed magnetic domains, with a feature size far smaller than the spatial extent of the excitation. We explain this pattern as a result of phase-synchronisation of magnon-polaron quasiparticles, driven by strong coupling of magnetic and elastic modes. Our results reveal not only the peculiar formation and evolution of magnon-polarons at short time-scales, but also present an alternative mechanism of magnetisation reversal driven by coherent packets of short-wavelength magnetoelastic waves.