Direct Observation of the Skyrmion Hall Effect

TL;DR

This paper reports the first direct real-space observation of the skyrmion Hall effect, demonstrating transverse skyrmion motion induced by current, which could enable new skyrmion-based technologies.

Contribution

It provides the first experimental evidence of the skyrmion Hall effect in real space using current-induced spin Hall torque at room temperature.

Findings

Observed a skyrmion Hall angle up to 15 degrees

Demonstrated skyrmion motion from creep to steady flow regime

Confirmed transverse motion due to topological charge

Abstract

The well-known Hall effect describes the transverse deflection of charged particles (electrons or holes) in an electric-current carrying conductor under the influence of perpendicular magnetic fields, as a result of the Lorentz force. Similarly, it is intriguing to examine if quasi-particles without an electric charge, but with a topological charge, show related transverse motion. Chiral magnetic skyrmions with a well-defined spin topology resulting in a unit topological charge serve as good candidates to test this hypothesis. In spite of the recent progress made on investigating magnetic skyrmions, direct observation of the skyrmion Hall effect in real space has, remained elusive. Here, by using a current-induced spin Hall spin torque, we experimentally observe the skyrmion Hall effect by driving skyrmions from creep motion into the steady flow motion regime. We observe a Hall angle for the magnetic skyrmion motion as large as 15 degree for current densities smaller than 10 MA/cm^(2) at room temperature. The experimental observation of transverse transport of skyrmions due to topological charge may potentially create many exciting opportunities for the emerging field of skyrmionics, including novel applications such as topological selection.