We have studied the transmission of surface acoustic waves (SAWs) in ferromagnetic/non-magnetic/ferromagnetic tryilayers. The SAW scattering matrix is studied for devices with various non-magnetic spacer thickness, which defines the strength of the interlayer exchange coupling. We find the SAW transmission amplitude depends on their propagation direction when the two ferromagnetic layers are coupled antiferromagnetically. The degree of such SAW nonreciprocity increases with increasing exchange coupling strength and reaches 37 dB/mm for a device with the thinnest spacer layer. These results show the potential of interlayer exchange coupled synthetic antiferromagnets for viable acoustic nonreciprocal transmission devices, such as circulators and isolators.
@article{arxiv.2203.16192,
title = {Large surface acoustic wave nonreciprocity in synthetic antiferromagnets},
author = {Hiroki Matsumoto and Takuya Kawada and Mio Ishibashi and Masashi Kawaguchi and Masamitsu Hayashi},
journal= {arXiv preprint arXiv:2203.16192},
year = {2022}
}