Spin-wave phase modulation using magnetic domain walls in dipolarly coupled structures for non-volatile magnonic computation

Abstract

A controllable phase shifter is a key component for spin-wave–based logic and information-processing devices. Here, we propose a domain-wall-position–controlled spin-wave phase shifter that exploits dipolar coupling between two closely spaced waveguides to enable continuous phase tuning over a range approaching 360° while keeping the spin-wave amplitude constant. Using micromagnetic simulations, we model a bias-free hybrid structure composed of a nanoscale waveguide magnetostatically coupled to a half-ring-shaped structure, both made from bismuth-doped yttrium iron garnet with strong perpendicular magnetic anisotropy. Displacing a domain wall in the half-ring modulates the dispersion relation in the adjacent straight waveguide due to the changed magnetostatic interaction, providing a compact and dynamically reconfigurable phase-shifting mechanism. This approach offers precise and non-volatile control over spin-wave propagation and is compatible with energy-efficient magnonic logic architectures.