Vanishing skyrmion Hall effect at the angular momentum compensation temperature of a ferrimagnet

TL;DR

This paper experimentally demonstrates that the skyrmion Hall effect vanishes at the angular momentum compensation temperature in ferrimagnets, confirming theoretical predictions and advancing skyrmionic device development.

Contribution

It provides the first experimental confirmation that the skyrmion Hall effect disappears at the angular momentum compensation point in ferrimagnets, linking spin density to the effect.

Findings

Skyrmion Hall effect vanishes at the angular momentum compensation temperature.

Current-driven ferrimagnetic bubbles show transverse elongation consistent with theoretical predictions.

The study confirms the link between fictitious magnetic field and net spin density.

Abstract

Charged particles exhibit the Hall effect in the presence of magnetic fields. Analogously, ferromagnetic skyrmions with non-zero topological charges and finite fictitious magnetic fields exhibit the skyrmion Hall effect, which is detrimental for applications. The skyrmion Hall effect has been theoretically predicted to vanish for antiferromagnetic skyrmions because the fictitious magnetic field, proportional to net spin density, is zero. We experimentally confirm this prediction by observing current-driven transverse elongation of pinned ferrimagnetic bubbles. Remarkably, the skyrmion Hall effect, estimated with the angle between the current and bubble elongation directions, vanishes at the angular momentum compensation temperature where the net spin density vanishes. This study establishes a direct connection between the fictitious magnetic field and spin density, offering a pathway towards the realization of skyrmionic devices.