Magnon-phonon coupling of synthetic antiferromagnets
We used a surface acoustic wave (SAW) cavity resonator to study the coupling of acoustic magnons in a synthetic antiferromagnet (SAF) and phonons carried by SAWs. The SAF is
composed of a CoFeB/Ru/CoFeB trilayer, and the scattering matrix of the SAW resonator is studied to assess the coupling. We estimate the magnon−phonon coupling strength to be ∼9.9 MHz at a SAW resonance frequency of 1.8 GHz: the corresponding magnomechanical cooperativity is ∼0.66. As the spectral shape hardly changes in a CoFeB single-layer reference sample, these results show that SAF provides an ideal platform to study magnon−phonon coupling in an SAW cavity resonator.
Magnon-phonon coupling of synthetic antiferromagnets in a surface acoustic wave cavity resonator
H. Matsumoto, I. Yasuda, M. Asano, T. Kawada, M. Kawaguchi, D. Hatanaka, M. Hayashi
Nano Lett. 24, 5683 (2024).
Highly non-reciprocal transmission of surface acoustic waves
We find the transmission of surface acoustic waves (SAWs) in ferromagnetic/non-magnetic/ferromagnetic tryilayers is non-reciprocal. The SAW transmission amplitude depends on its propagation direction when the two ferromagnetic layers are coupled antiferromagnetically. The degree of such SAW nonreciprocity increases with increasing exchange coupling strength. These results show the potential of interlayer exchange coupled synthetic antiferromagnets for viable acoustic nonreciprocal transmission devices, such as circulators and isolators.
Large surface acoustic wave nonreciprocity in synthetic antiferromagnets
H. Matsumoto, T. Kawada, M. Ishibashi, M. Kawaguchi, M. Hayashi
Appl. Phys. Express 15, 063003 (2022).