Duplication, collapse and escape of magnetic skyrmions revealed using a systematic saddle point search method

TL;DR

This paper systematically investigates the transition processes of magnetic skyrmions, including collapse, escape, and duplication, using a saddle point search method, revealing new pathways for skyrmion manipulation.

Contribution

It introduces a systematic saddle point search method to identify various skyrmion transition pathways, including duplication, which was not well understood before.

Findings

Skyrmion can undergo duplication, collapse, and escape transitions.

Activation energies for duplication are comparable to collapse and escape.

Magnetic field tilting can induce skyrmion duplication in simulations.

Abstract

Various transitions that a magnetic skyrmion can undergo are found in calculations using a method for climbing up the energy surface and converging onto first order saddle points. In addition to collapse and escape through a boundary, the method identifies a transition where the skyrmion divides and forms two skyrmions. The activation energy for this duplication process can be similar to that of collapse and escape. A tilting of the external magnetic field for a certain time interval is found to induce the duplication process in a dynamical simulation. Such a process could turn out to be an important avenue for the creation of skyrmions in future magnetic devices.