Nutational switching in ferromagnets and antiferromagnets

It was demonstrated recently that on ultrashort time scales magnetization dynamics does not only exhibit precession but also nutation. Here, we investigate how nutation can contribute to spin switching leading towards ultrafast data writing. We use analytic theory and atomistic simulations discuss the behavior of ferromagnets antiferromagnets in high-frequency magnetic fields. In ferromagnets, linearly polarized fields align perpendicular external field, enabling $90^{\circ}$ switching. For circularly $xy$ plane, tilts $z$ direction. During this tilting, it rotates around axis, allowing $180^{\circ}$ antiferromagnets, with frequencies higher than frequency order parameter parallel field direction, while for lower is oriented field. The increases strength, deviates from Larmor frequency, making possible outpace precessional high