Journal of Magnetism and Magnetic Materials | 2021
Fast control of the polarity of the magnetic vortex for a pair of magnetic nanodots
Abstract
Abstract In order to control the polarity of the magnetic vortex, a pair of fast pulsed magnetic fields is applied on a permalloy nanodot pair. The pair of pulsed fields consists of two perpendicular magnetic field pulses with a certain time interval. The width of each pulse is about hundreds of picoseconds, and the amplitude is just ~20–30 mT. The two pulses can be considered as a CW or a CCW rotating pulsed magnetic field. The rotation direction of the pulsed field determines the final polarity regardless of the initial vortex state. We analyzed the controllability of the polarity in terms of energy, which in turn is related to the amplitude and the width of the pulse. When the frequency of the rotating magnetic field is 1.25\xa0GHz, which is equal to the eigenfrequency of the system, the minimum pulse amplitude is achieved to reverse the polarity.