Magnetization reversal in the anisotropy-dominated regime using time-dependent magnetic fields

The authors study magnetization reversal using various rf magnetic pulses. The authors show numerically that switching is possible with simple sinusoidal pulses; however, the optimum approach is to use a frequency-swept (chirped) rf magnetic pulse, the shape of which can be derived analytically. Switching times of the order of nanoseconds can be achieved with relatively small rf fields, independent of the anisotropy’s strength.