Fast switching of magnetic vortex state under an alternating magnetic field

Abstract

Abstract Vortex is considered to be a promising candidate for nonvolatile magnetic random storage devices due to its unique binary state and high thermal stability. The control of vortex polarity and chirality is key to devices based on vortex. In this work, the switching of the magnetic vortex state in Permalloy nanodisks has been investigated by micromagnetic simulation employing in-plane alternating magnetic fields. During the switching of magnetic vortex state, an antivortex is formed, and the antivortex and vortex will not annihilate together. The formation of antivortex and the annihilation of initial vortex lead to the switching of magnetic vortex state. The switching of vortex state depends on magnetic field and disk size. The switching time of magnetic vortex state declines with the enhancement of magnetic field amplitude or magnetic field frequency. All the switching can be completed within 1.4 ns, indicating that the alternating magnetic field driving can induce the rapid switching of vortex state. This work provides an effective method for the fast switching of magnetic vortex state, which benefits the potential storage applications in vortex-based spintronic devices.