Spin wave localization in a magnonic crystal with a defect

Abstract

Defects are typically regarded as detrimental in crystalline systems whose physical properties rely on symmetry. However, lattice defects are known to be an effective solution for applications requiring energy localization. Here, we report the experimental observation of spin wave localization in a one-dimensional magnonic crystal with broken translational symmetry. By operating in the diffractive regime, we directly image energy localization in both space and time using a magneto-inductive probe. This work provides the first direct space- and time-resolved experimental evidence of spin wave localization in a diffractive regime due to a single structural defect. These findings are in good agreement with theoretical simulations, validating the underlying physical mechanism.