Magnetic skyrmion binning

TL;DR

This paper investigates the use of spin transfer torque to mechanically sort skyrmions of different topological degrees in thin ferromagnetic films, combining micromagnetic simulations and theoretical analysis.

Contribution

It introduces a new theoretical framework for skyrmion deflection based on topological degree and assesses the Thiele equation's applicability to skyrmion binning.

Findings

Skyrmion deflection varies with topological degree.

Thiele equation can be adapted to predict skyrmion trajectories.

Potential for mechanically sorting skyrmions by degree.

Abstract

When spin polarised electrons flow through a magnetic texture a transfer torque is generated. We examine the effect of this torque on skyrmions and skyrmion bags, skyrmionic structures of arbitrary integer topological degree, in thin ferromagnetic films. Using micromagnetic simulations and analysis from the well known Thiele equation we explore the potential for sorting or binning skyrmions of varying degrees mechanically. We investigate the applicability of the Thiele equation to problems of this nature and derive a theory of skyrmion deflection ordered by topological degree.