Nonreciprocal magnetoacoustic waves in synthetic antiferromagnets with Dzyaloshinskii-Moriya interaction

The interaction between surface acoustic waves (SAWs) and spin (SWs) in a piezoelectric/magnetic thin film heterostructure yields potential for the realization of novel microwave devices applications magnonics. In present work, we investigate SAW-SW Pt/Co($2\phantom{\rule{0.16em}{0ex}}\mathrm{nm}$)/Ru($0.85\phantom{\rule{0.16em}{0ex}}\mathrm{nm}$)/Co($4\phantom{\rule{0.16em}{0ex}}\mathrm{nm}$)/Pt synthetic antiferromagnet (SAF) composed two ferromagnetic layers with different thicknesses separated by nonmagnetic Ru spacer layer. Because combined presence interfacial Dzyaloshinskii--Moriya (iDMI) interlayer dipolar coupling fields, optical SW mode shows large nondegenerate dispersion relation oppositely propagating SWs. Due to interaction, observe nonreciprocal SAW transmission piezoelectric/SAF hybrid device. equilibrium magnetization directions both Co are manipulated an external magnetic field set ferromagnetic, canted, or antiferromagnetic configuration. This has strong impact on dispersion, its nonreciprocity, interaction. experimental results agreement phenomenological model, which considers exchange coupling, iDMI, fields