Large anomalous Nernst effect in a metallic altermagnet CrSb single crystal

As a novel magnetism that combines features of ferromagnetism and antiferromagnetism, altermagnetism is attracting great attention due to its special energy band structure and potential application prospects. The NiAs-type metallic CrSb was proposed to be a new altermagnet, which has been experimentally verified by spin-resolved angle-resolved photoemission spectroscopy. In this work, we show the magnetic, electrical, and thermoelectric properties of CrSb single crystals. It is found that the thermoelectricity exhibits an anomalous Nernst effect (ANE) with the value of $|{S}_{zy}^{A}|\ensuremath{\sim}0.3\phantom{\rule{4pt}{0ex}}\textmu{}\mathrm{V}/\mathrm{K}$, which is comparable to the value in the ferromagnetic metals. In addition, first-principles calculation shows that the experimental results are qualitatively consistent with the characteristics of an altermagnet and support the observation of ANE. This work not only provides a splendid bulk platform to study altermagnet physics, but also indicates that ANE is a highly effective method to study alternating spin-splitting band structure near the Fermi level and will greatly intrigue the research interest of ANE in altermagnets.