Polarization-Selective Excitation of Antiferromagnetic Resonance in Perpendicularly Magnetized Synthetic Antiferromagnets

Unlike ferromagnets, collinear antiferromagnets have two precession modes exhibiting opposite chirality, which enables the use of the polarization degree of freedom of magnons. In this study, we experimentally measure the polarization-selective spectra of magnetic resonance in perpendicularly magnetized synthetic antiferromagnets using a wideband crossed microstrip circuit. The magnetic resonances with right-handed and left-handed precession modes are directly detected, and theoretical analysis and numerical simulations explain the measurement results by considering the difference in the perpendicular magnetic anisotropy and damping constant between the top and bottom ferromagnetic layers. We also show that magnetic excitations with different polarization types can be excited under degeneracy between the two precession modes. Our work suggests that perpendicularly magnetized synthetic antiferromagnet structures provide an attractive platform for manipulating the polarization degree of freedom of magnons.

Automated summary

In this study, the polarization-selective spectra of magnetic resonance in perpendicularly magnetized synthetic antiferromagnets were experimentally measured using a wideband crossed microstrip circuit. The magnetic resonances with different precession modes were observed, and the measurement results were explained by theoretical analysis and numerical simulations. It was also shown that magnetic excitations with different polarization types can be excited.