Shaping non-reciprocal caustic spin-wave beams
Résumé
Mastering spin waves interference at the sub-micron scale is central for the development of wave-based computing applications such as reservoir computing [1], holographic memory, or spectral analysis. The complexity of spin dynamics, inherently due to its dependence to numerous parameters, and the intricacy of magnon-magnon interactions, requires heavy computational methods, which can limit the scope of study. In this context, we developed an efficient tool to study the near-field diffraction (NFD) patterns of spin wave in homogeneous out-of-plane magnetized thin films for arbitrary distribution of excitation fields [2, 3]. In this communication, we present the adaptation of our NFD model to in-plane magnetized thin films, and reveal how caustic spin-wave beams can be directly emitted from a sharply constricted stripline. We show in particular the importance of not only meeting the suitable caustic conditions of field and frequency (see Fig. 1), but also having of a seemingly punctual source for shaping the caustic beam. Using spatially resolved micro-focused Brillouin light spectroscopy on various constriction sizes, we satisfyingly verify our predictions, and explore further the steerability as well as the caustic beams properties.
Domaines
Physique [physics]| Origine | Fichiers produits par l'(les) auteur(s) |
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