Correlating on-the-fly Electrical and Optical Skyrmion Readout

TL;DR

This paper presents a novel method for reliably detecting individual magnetic skyrmions in real-time by correlating electrical Hall voltage signals with optical Kerr microscopy, enabling scalable and precise skyrmion readout for future memory and computing devices.

Contribution

The authors introduce a thermally activated skyrmion detection technique that correlates Hall voltage signals with optical imaging, providing a scalable and reliable readout method for skyrmions.

Findings

Real-time correlation between Hall voltage and Kerr microscopy confirms skyrmion detection.

Analytical formula for skyrmion AHE readout demonstrates scalability.

Method enables detection of single skyrmions from micrometer to nanometer scales.

Abstract

Magnetic skyrmions, topologically stabilized spin textures, are promising candidates for future memory devices and non-conventional computing applications due to their enhanced stability, non-linear interactions, and low-power manipulation capabilities. Despite their significant potential, the reliable electrical readout of individual skyrmions remains a fundamental challenge. While magnetic tunnel junctions and anomalous Hall effect (AHE)-based techniques have demonstrated skyrmion detection capabilities, they currently fail to reliably detect single moving skyrmions as required for applications. Our approach leverages thermally activated skyrmions, where a low constant drive current simultaneously generates both skyrmion motion and the Hall voltage necessary for detection. We demonstrate the reliability of this method through real-time correlation between measured Hall voltage signals and direct Kerr microscopy imaging. Two consecutive Hall crosses allow for determining the skyrmion velocity, in accordance to Kerr microscopy videos. We present an analytical formula for the skyrmion AHE readout signal, demonstrating scalability from micrometer to nanometer skyrmions. These advances establish a robust platform for skyrmion-based sensors, counters and unconventional computing systems that depend on precise individual skyrmion control and detection.