Spin-wave circulation in unbounded ferromagnetic film

A key challenge in spin-wave computing is steering spin waves through circuits without wave distortion or reflections. This often results in 1D propagation scenarios, which hinder applicability in 2D magnonic circuits. We demonstrate experimentally a novel approach using a hard magnetic spherical microparticle to guide spin-waves onto a closed path in a plain thin YIG film. The particle stray field induces a radially symmetrical magnetization landscape, which allows spin-waves to loop around. In parallel, we conducted micromagnetic simulations reproducing the experimental conditions, which confirm the circulation of spin-waves over several loops around the particle. This work demonstrates the possibility to steer spin-waves onto a circular path using inhomogeneous magnetic landscape, as well as advancing scalable spin-wave-based information processing technologies.