SIMULATING RESONANT MAGNETIZATION REVERSALS IN NANOMAGNETS

An efficient way to perform microwave-assisted switching of small ferromagnetic samples is studied. Magnetization reversals in cylindrical Yttrium Iron Garnet nanomagnets are simulated by applying a fixed-frequency transverse microwave field and a time-varying longitudinal applied field along the direction of the static field so as to continually match the precession frequency with the microwave frequency. The ideal form of microwave field is circularly polarized, and we also studied linearly polarized microwave fields since they are simpler to implement. Inhomogeneous modes nucleate in larger samples with dimensions several times larger than an exchange length which leads to incomplete switching.