Spin wave diffraction and Talbot carpets in YIG films with in-plane magnetization

A plane wave passing through a diffraction grating interferes. In the near field, the diffraction pattern reproduces the grating image at specific distances in so-called Talbot carpets, which were first observed in optics in the 19th century [1]. Recently, the formation of Talbot carpets has been simulated for magnonic systems [2] and their relevance for programmable spin-wave gate arrays has been presented [3]. Here, we report on spin wave diffraction in continuous YIG films with in-plane magnetization and patterned CoFeB nanostripes on top. We use magnonic Fabry-Pérot resonances [4] to create a slit grating for spin waves and image the resulting interference pattern using super-Nyquist sampling magneto-optic Kerr effect microscopy. We observe a transition from wave diffraction to the generation of magnonic caustic beams [5] as a function of the slit size. In the diffraction regime, magnonic Talbot carpets are formed. Our results provide insights into self-imaging effects in magnonics and offer new implementation strategies for spin-wave computing.



[1] H. Talbot, Philos. Mag. J. Sci. 9, 401 (1836).

[2] M. Gołębiewski et al., Phys. Rev. B 102, 134402 (2020).

[3] M. Gołębiewski et al., Adv. Electron. Mater. 8, 2200373 (2022).

[4] H. Qin et al., Nat. Commun. 12, 2293 (2021).

[5] A.Wartelle et al., Phys. Rev. B 107, 144431 (2023).