Skyrmion formation in a bulk chiral magnet at zero magnetic field and above room temperature

TL;DR

This study demonstrates the creation and stability of metastable skyrmions in a bulk chiral magnet at room temperature and zero magnetic field, highlighting their potential for technological applications.

Contribution

It reveals that metastable skyrmions can be formed and remain stable at room temperature and zero magnetic field in a bulk chiral magnet, a novel finding for practical use.

Findings

Metastable skyrmions are realized over a wide temperature range including room temperature.

Skyrmions survive at zero magnetic field at and above room temperature.

The stability is attributed to the topological nature of skyrmions.

Abstract

We report that in a $\beta$-Mn-type chiral magnet Co$_9$Zn$_9$Mn$_2$, skyrmions are realized as a metastable state over a wide temperature range, including room temperature, via field-cooling through the thermodynamic equilibrium skyrmion phase that exists below a transition temperature $T_\mathrm{c}$ $\sim$ 400 K. The once-created metastable skyrmions survive at zero magnetic field both at and above room temperature. Such robust skyrmions in a wide temperature and magnetic field region demonstrate the key role of topology, and provide a significant step toward technological applications of skyrmions in bulk chiral magnets.