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arXiv · 2404.15011

Shaping non-reciprocal caustic spin-wave beams

Dinesh Wagle·Daniel Stoeffler·Loic Temdie·Mojtaba Taghipour Kaffash·Vincent Castel·H. Majjad·R. Bernard·Yves Henry·Matthieu Bailleul·M. Benjamin Jungfleisch·Vincent Vlaminck
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Abstract

A caustic is a mathematical concept describing the beam formation when the beam envelope is reflected or refracted by a manifold. While caustics are common in a wide range of physical systems, caustics typically exhibit a reciprocal wave propagation and are challenging to control. Here, we utilize the highly anisotropic dispersion and inherent non-reciprocity of a magnonic system to shape non-reciprocal emission of caustic-like spin wave beams in an extended 200 nm thick yttrium iron garnet (YIG) film from a nano-constricted rf waveguide. We introduce a near-field diffraction model to study spin-wave beamforming in homogeneous in-plane magnetized thin films, and reveal the propagation of non-reciprocal spin-wave beams directly emitted from the nanoconstriction by spatially resolved micro-focused Brillouin light spectroscopy (BLS). The experimental results agree well with both micromagnetic simulation, and the near-field diffraction model. The proposed method can be readily implemented to study spin-wave interference at the sub-micron scale, which is central to the development of wave-based computing applications and magnonic devices.

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Dinesh Wagle, Daniel Stoeffler, Loic Temdie, Mojtaba Taghipour Kaffash, Vincent Castel, H. Majjad, R. Bernard, Yves Henry, Matthieu Bailleul, M. Benjamin Jungfleisch, Vincent Vlaminck. 2024-04-23. Shaping non-reciprocal caustic spin-wave beams. https://doi.org/10.1103/qz9q-bp9j

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