Vortex polarity switching by a spin--polarized current

TL;DR

This paper demonstrates that spin-polarized currents can effectively switch the vortex polarity in magnetic nanodots, offering a promising method for magnetic storage device control.

Contribution

It introduces a novel understanding of vortex polarity switching driven by spin currents, supported by energy analysis and spin-lattice simulations.

Findings

Spin current acts like an effective magnetic field perpendicular to the nanodot.

Vortex polarity can be switched by spin current more efficiently than by magnetic fields.

Predicted vortex polarity switching through theoretical and simulation approaches.

Abstract

The spin-transfer effect is investigated for the vortex state of a magnetic nanodot. A spin current is shown to act similarly to an effective magnetic field perpendicular to the nanodot. Then a vortex with magnetization (polarity) parallel to the current polarization is energetically favorable. Following a simple energy analysis and using direct spin--lattice simulations, we predict the polarity switching of a vortex. For magnetic storage devices, an electric current is more effective to switch the polarity of a vortex in a nanodot than the magnetic field.