A magnonic metamaterial in the presence of spatially modulated Dzyaloshinskii–Moriya interaction is theoretically proposed and demonstrated by micromagnetic simulations. By analogy to the fields of photonics, we first establish magnonic Snell’s law for spin waves passing through an interface between two media with different dispersion relations due to different Dzyaloshinskii–Moriya interactions. Based on magnonic Snell’s law, we find that spin waves can experience total internal reflection. The critical angle of total internal reflection is strongly dependent on the sign and strength of Dzyaloshinskii–Moriya interaction. Furthermore, spin-wave beam fiber and spin-wave lens are designed by utilizing the artificial magnonic metamaterials with inhomogeneous Dzyaloshinskii–Moriya interactions. Our findings open up a rich field of spin waves manipulation for prospective applications in magnonics.
Bibliographical noteKAUST Repository Item: Exported on 2022-04-01
Acknowledgements: F.Z. and H.L. acknowledge the support from National Key R&D Program of China (No. 2018YFB0407600), Henan University (No. CJ3050A0240050) and National Natural Science Foundation of China (No. 11804078). F.Z. was supported by King Abdullah University of Science and Technology (KAUST). A.M. acknowledges support from the Excellence Initiative of Aix-Marseille Université—A*Midex, a French “Investissements d’Avenir” program. Z.C. acknowledges the support from Grant No. ARC (DP190100150).