Electric‐Field Control of Propagating Spin Waves by Ferroelectric Domain‐Wall Motion in a Multiferroic Heterostructure

Abstract Magnetoelectric coupling in multiferroic heterostructures offers a promising platform for electric‐field control of magnonic devices based on low‐power spin‐wave transport. Here, electric‐field manipulation of the amplitude and phase of propagating spin waves in a ferromagnetic Fe film on top of a ferroelectric BaTiO₃ substrate is demonstrated experimentally. Electric‐field effects in this composite material system are mediated by strain coupling between alternating ferroelectric stripe domains with in‐plane and perpendicular polarization and fully correlated magnetic anisotropy domains with differing spin‐wave transport properties. The propagation of spin waves across the strain‐induced magnetic anisotropy domains of the Fe film is directly imaged and it is shown how reversible electric‐field‐driven motion of ferroelectric domain walls and pinned anisotropy boundaries turns the spin‐wave signal on and off. Furthermore, linear electric‐field tuning of the spin‐wave phase by altering the width of strain‐coupled stripe domains is demonstrated. The results provide a new route toward energy‐efficient reconfigurable magnonics.