Motion and Switching of Dual-vortex Cores in Elliptical Permalloy Nanodisk Stimulated by a Gaussian Magnetic Field Pulse

Abstract

Magnetic nanodisks with magnetic vortex structure have attracted a great deal of attention due to the potential application in nonvolatile magnetic memories. While the dynamics of single magnetic vortex are well understood, the displacement of the equilibrium positions and the switching of polarity and chirality of dual-vortex cores driven Guassian field pulses are not yet reported. In this work, we investigated the motion of dual-vortex cores in elliptical permalloy nanodisk through micromagnetic modeling. We found that the equilibrium positions of dual-vortex cores can be displaced through applying a short-axis Gaussian field pulse and a long-axis constant field. The reliance of the displacement on the pulse width and strength are investigated under different long-axis constant field. We further studied the switching behavior of the polarity and chirality by Gaussian field pulses with various pulse width and strength. This work shows that the equilibrium position, polarity and chirality of dual-vortex cores can be manipulated by tuning the profile of the Gaussian field pulse and the magnitude of the constant field. The results of this work are important for understanding the magnetization dynamics of nanostructures containing dual vortices subject to external excitations.