Discrete Hall resistivity contribution from N\'{e}el skyrmions in multilayer nanodiscs

TL;DR

This study demonstrates room-temperature skyrmions in Pt/Co/Ir nanodiscs and reveals a discrete Hall resistivity contribution from individual skyrmions, crucial for electrical detection in skyrmion-based devices.

Contribution

It reports a quantized Hall resistivity contribution from individual skyrmions, independent of their size, in nanodiscs at room temperature.

Findings

Each skyrmion contributes approximately 22 nΩ·cm to Hall resistivity.

The resistivity contribution is independent of skyrmion size.

The results enable electrical detection of skyrmions in spintronic devices.

Abstract

Magnetic skyrmions are knot-like quasiparticles. They are candidates for non-volatile data storage in which information is moved between fixed read and write terminals. Read-out operation of skyrmion-based spintronic devices will rely upon electrical detection of a single magnetic skyrmion within a nanostructure. Here, we present Pt/Co/Ir nanodiscs which support skyrmions at room temperature. We measured the Hall resistivity whilst simultaneously imaging the spin texture using magnetic scanning transmission x-ray microscopy (STXM). The Hall resistivity is correlated to both the presence and size of the skyrmion. The size-dependent part matches the expected anomalous Hall signal when averaging the magnetisation over the entire disc. We observed a resistivity contribution which only depends on the number and sign of skyrmion-like objects present in the disc. Each skyrmion gives rise to 22$\pm$2 n{\Omega} cm irrespective of its size. This contribution needs to be considered in all-electrical detection schemes applied to skyrmion-based devices.