Control of the chirality and polarity of magnetic vortices in triangular nanodots

TL;DR

This paper demonstrates that triangular nanodots can be used to control both the chirality and polarity of magnetic vortices through in-plane and out-of-plane magnetic fields, with potential applications in non-volatile memory devices.

Contribution

It introduces a method to control vortex chirality and polarity in triangular nanodots, combining experimental imaging and micromagnetic simulations, advancing magnetic memory technology.

Findings

Vortex chirality can be tailored by in-plane magnetic fields.

Vortex polarity can be controlled with out-of-plane magnetic fields.

Short magnetic pulses can switch vortex polarity, longer pulses switch chirality.

Abstract

Magnetic vortex dynamics in lithographically prepared nanodots is currently a subject of intensive research, particularly after recent demonstration that the vortex polarity can be controlled by in-plane magnetic field. This has stimulated the proposals of non-volatile vortex magnetic random access memories. In this work, we demonstrate that triangular nanodots offer a real alternative where vortex chirality, in addition to polarity, can be controlled. In the static regime, we show that vortex chirality can be tailored by applying in-plane magnetic field, which is experimentally imaged by means of Variable-Field Magnetic Force Microscopy. In addition, the polarity can be also controlled by applying a suitable out-of-plane magnetic field component. The experiment and simulations show that to control the vortex polarity, the out-of-plane field component, in this particular case, should be higher than the in-plane nucleation field. Micromagnetic simulations in the dynamical regime show that the magnetic vortex polarity can be changed with short-duration magnetic field pulses, while longer pulses change the vortex chirality.