Spin waves in the two-dimensional Ammann−Beenker quasicrystals

We investigate spin wave (SW) spectra in two-dimensional (2D) magnonic quasicrystals (MQCs) based on Ammann−Beenker (AB) tiling using micromagnetic simulations. The AB MQC structure is realized as an antidot lattice (ADL) etched into a thin Permalloy (Py) strip, generated via projection from a four-dimensional (4D) hypercube onto a 2D plane within a selection window in perpendicular space. Our simulations reveal SW dispersion with distinct circular ring patterns in frequency slices. The centers of these rings coincide with high-intensity diffraction points predicted by the higher-dimensional projection method, and their intensity correlates with corresponding diffraction peaks, confirming origins from Bragg reflection. The spectra exhibit numerous band gaps and fractal characteristics inherent to quasiperiodicity. Crucially, band gap tuning can be achieved by scaling the perpendicular-space selection window, which modifies diffraction intensities and thereby adjusts the SW band structure. This introduces a new design degree of freedom for reconfigurable magnonic devices. Our results demonstrate the effectiveness of the higher-dimensional projection method for analyzing MQC SW dispersion and highlight the potential of quasiperiodic modulation in engineering SW spectra for low-cost, reconfigurable spintronic applications.