The aim of this project is to study magnetization reversal of individual magnetic nanoparticles under a frequency modulated RF magnetic field pulses. We have shown in previous works how a monochromatic RF pulse can, by means of a non-linear resonance, substantially reduce the required static field needed to reverse the magnetization of an individual nanoparticle. More recently, we demonstrated how the phase sensitivity of microwave-assisted switching of an individual cobalt nanoparticle can be studied using a pump-probe technique. This work showed how the magnetization can reach a dynamic state where it is trapped, even when applying a rf field that would have switched the magnetization starting from the equilibrium in the metastable energy well. Controlling the phase of this driving signal can thus increase its efficiency with no additional cost in terms of energy or time.
The aim of this project is to study magnetization reversal of individual magnetic nanoparticles under a frequency-modulated RF magnetic field pulse.