Edge-soliton-meditated fast vortex core dynamic switching in a notched magnetic disk

Abstract

Magnetic vortices are characterized by the sense of in-plane magnetization chirality and by the polarity of the vortex core. Searching for efficient ways to control the vortex polarity and chirality is of highly fundamental and practical significance towards high speed and high density non-volatile memory applications. Here we report a novel vortex core (VC) switching process in a notched disk, driven by a pulse field. Micromagnetic simulations demonstrate that the dynamics of edge solitons around the notch play a critical role in the switching process, that leads to a sub-nanosecond VC fast switching. The switching diagram as a function of the field strength and duration was presented to indicate the operational range. Further studies on the VC switching under an out-of-plane bias field demonstrate that such switching is deterministic and robust against magnetic environment. Finally, by applying a resonant alternative field, a periodic VC switching is observed with much reduced switching field. The presented results indicate the potential of notched disks for VC based memory applications.