Controlling the chirality and polarity of vortices in magnetic tunnel junctions

Abstract : Static and dynamic control of the chirality and polarity of a magnetic vortex confined in a magnetic tunnel junction is demonstrated. The modes associated with the four chirality/polarity vortex configurations are first explored by resonant excitation with a low power rf current. When the rf power is increased, both the chirality and polarity of the vortex can be resonantly switched, which—as shown by micromagnetic simulations—involves vortex expulsion and renucleation. This tunable resonant switching of the vortex parameters are an exciting step forward for the viability of magnetic vortex-based applications.