Thermoelectric microscopy of magnetic skyrmions

TL;DR

This paper introduces a novel thermoelectric microscopy technique to image magnetic skyrmions by detecting spin-caloritronic signals induced by localized heating, enabling visualization of skyrmion textures and dynamics.

Contribution

The study demonstrates a new thermoelectric imaging method for magnetic skyrmions using local heating and thermoelectric signals, offering a non-invasive way to observe skyrmion behavior.

Findings

Skyrmions can be imaged via thermoelectric signals linked to their magnetic textures.

The method allows mapping of thermoelectric current distributions related to skyrmions.

Skyrmion dynamics under current pulses can be observed with this technique.

Abstract

The magnetic skyrmion is a nanoscale topological object characterized by the winding of the magnetic moments, appearing in magnetic materials with broken inversion symmetry. Because of its low current threshold for driving, the skyrmions have been intensely studied toward novel storage applications by using electron-beam, X-ray, and visible light microscopies. Here, we show that the skyrmions can be imaged via thermoelectric signals of spin-caloritronic phenomena in combination with focused heating. We applied a local temperature gradient to a CoFeB/Ta/W multilayer film with scanning a heating position and, by exploiting a Hall bar structure, mapped the magnitude as well as the direction of the resultant thermoelectric current distributions, which link to skyrmions' inner magnetic textures. This method also enables the observation of skyrmion dynamics under driving current pulses, being a useful imaging technique for the development of skyrmion devices.