Current-induced magnetic vortex core switching in a Permalloy nanodisk

TL;DR

This paper demonstrates that short current pulses can reliably switch the magnetic vortex core in a Permalloy nanodisk, enabling potential applications in dense magnetic memory and logic devices.

Contribution

It introduces a method for vortex core switching using current pulses and provides micromagnetic simulations to understand the dynamics involved.

Findings

Core reversal can be triggered by current bursts as short as 0.1 nanoseconds.

The switching process is analogous to external field pulse induced reversal.

Current control allows addressing individual nanomagnets in dense arrays.

Abstract

We report on the switching of a magnetic vortex core in a sub-micron Permalloy disk, induced by a short current pulse applied in the film plane. Micromagnetic simulations including the adiabatic and non-adiabatic spin-torque terms are used to investigate the current-driven magnetization dynamics. We predict that a core reversal can be triggered by current bursts a tenth of a nanosecond long. The vortex core reversal process is found to be the same as when an external field pulse is applied. The control of a vortex core's orientation using current pulses introduces the technologically relevant possibility to address individual nanomagnets within dense arrays.