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

We report that in a beta-Mn-type chiral magnet Co9Zn9Mn2, 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-c similar to 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.