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arXiv · 2410.06167

Broken intrinsic symmetry induced magnon-magnon coupling in synthetic ferrimagnets

Mohammad Tomal Hossain·Hang Chen·Subhash Bhatt·Mojtaba Taghipour Kaffash·Mitra M. Subedi·John Q. Xiao·Joseph Sklenar·M. Benjamin Jungfleisch
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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 non-magnetic 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.

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Mohammad Tomal Hossain, Hang Chen, Subhash Bhatt, Mojtaba Taghipour Kaffash, Mitra M. Subedi, John Q. Xiao, Joseph Sklenar, M. Benjamin Jungfleisch. 2024-10-08. Broken intrinsic symmetry induced magnon-magnon coupling in synthetic ferrimagnets. https://doi.org/10.1103/4vyj-8vyq

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