Magnon-magnon coupling induced by broken intrinsic symmetry in synthetic ferrimagnets
Phys. Rev. Applied 25, 044018 – Published 7 April, 2026
DOI: https://doi.org/10.1103/4vyj-8vyq
Abstract
Synthetic antiferromagnets offer rich magnon energy spectra in which optical and acoustic magnon branches can hybridize. Here, we demonstrate a broken-intrinsic-symmetry-induced coupling of acoustic and optical magnons in a synthetic ferrimagnet consisting of two dissimilar antiferromagnetically interacting ferromagnetic metals. Two distinct magnon modes hybridize at degeneracy points, as indicated by an avoided level crossing. The avoided level crossing gap depends on the interlayer exchange interaction between the magnetic layers, which can be controlled by adjusting the nonmagnetic interlayer thickness. A large avoided level crossing gap of 3.9 GHz is revealed, exceeding the coupling strength that is typically found in other magnonic hybrid systems based on a coupling of magnons with photons or magnons with phonons.
