Deterministic generation of skyrmions and antiskyrmions by electric current

TL;DR

This paper demonstrates the controlled, on-demand creation of magnetic skyrmions and antiskyrmions in a chiral magnet using electric current, without external magnetic fields, enabling potential spintronic device applications.

Contribution

It introduces a method to generate and control skyrmions and antiskyrmions solely with electric current, expanding the possibilities for electric-controlled spintronic devices.

Findings

Skyrmions and antiskyrmions can be generated by current flow direction.

Generation occurs via edge instability of the helical state.

Micromagnetic simulations support experimental results.

Abstract

Magnetic skyrmions are nanoscale spin whirlpools that promise breakthroughs in future spintronic applications. Controlled generation of magnetic skyrmions by electric current is crucial for this purpose. While previous studies have demonstrated this operation, the topological charge of the generated skyrmions is determined by the direction of the external magnetic fields, thus is fixed. Here, we report the current-induced skyrmions creation in a chiral magnet FeGe nanostructure by using the \emph{in-situ} Lorentz transmission electron microscopy. We show that magnetic skyrmions or antiskyrmions can be both transferred from the magnetic helical ground state simply by controlling the direction of the current flow at zero magnetic field. The force analysis and symmetry consideration, backed up by micromagnetic simulations, well explain the experimental results, where magnetic skyrmions or antiskyrmions are created due to the edge instability of the helical state in the presence of spin transfer torque. The on-demand generation of skyrmions and control of their topology by electric current without the need of magnetic field will enable novel purely electric-controlled skyrmion devices.