Electrical switching of vortex core in a magnetic disk

TL;DR

This paper demonstrates electrical switching of a magnetic vortex core in a ferromagnetic disk using current-driven resonant dynamics, advancing the development of vortex-based nonvolatile memory devices.

Contribution

It introduces a method for electrically controlling vortex core magnetization via resonance, enabling potential spintronic memory applications.

Findings

Core switching achieved without magnetic fields.

Resonant dynamics enable efficient switching.

Core speeds reach several hundred m/s.

Abstract

A magnetic vortex is a curling magnetic structure realized in a ferromagnetic disk, which is a promising candidate of a memory cell for future nonvolatile data storage devices. Thus, understanding of the stability and dynamical behaviour of the magnetic vortex is a major requirement for developing magnetic data storage technology. Since the experimental proof of the existence of a nanometre-scale core with out-of-plane magnetisation in the magnetic vortex, the dynamics of a vortex has been investigated intensively. However, the way to electrically control the core magnetisation, which is a key for constructing a vortex core memory, has been lacking. Here, we demonstrate the electrical switching of the core magnetisation by utilizing the current-driven resonant dynamics of the vortex; the core switching is triggered by a strong dynamic field which is produced locally by a rotational core motion at a high speed of several hundred m/s. Efficient switching of the vortex core without magnetic field application is achieved thanks to resonance. This opens up the potentiality of a simple magnetic disk as a building block for spintronic devices like a memory cell where the bit data is stored as the direction of the nanometre-scale core magnetisation.