The anomalous Nernst effect generates transverse voltage to the applied thermal gradient in magnetically ordered systems. The effect was previously considered excluded in compensated magnetic materials with collinear ordering. However, in the recently identified class of compensated magnetic materials, dubbed altermagnets, time-reversal symmetry breaking in the electronic band structure makes the presence of the anomalous Nernst effect possible despite the collinear spin arrangement. In this work, we investigate epitaxial Mn5Si3 thin films known to be an altermagnetic candidate. We show that the material manifests a sizable anomalous Nernst coefficient despite the small net magnetization of the films. The measured magnitudes of the anomalous Nernst coefficient reach a scale of microVolts per Kelvin. We support our magneto-thermoelectric measurements by density-functional theory calculations of the material's spin-split electronic structure, which allows for the finite Berry curvature in the reciprocal space. Furthermore, we present our calculations of the intrinsic Berry-curvature Nernst conductivity, which agree with our experimental observations.
@article{arxiv.2403.12929,
title = {Observation of the anomalous Nernst effect in altermagnetic candidate Mn5Si3},
author = {Antonin Badura and Warlley H. Campos and Venkata K. Bharadwaj and Ismaïla Kounta and Lisa Michez and Matthieu Petit and Javier Rial and Miina Leiviskä and Vincent Baltz and Filip Krizek and Dominik Kriegner and Jan Zemen and Sjoerd Telkamp and Sebastian Sailler and Michaela Lammel and Rodrigo Jaeschke Ubiergo and Anna Birk Hellenes and Rafael González-Hernández and Jairo Sinova and Tomáš Jungwirth and Sebastian T. B. Goennenwein and Libor Šmejkal and Helena Reichlova},
journal= {arXiv preprint arXiv:2403.12929},
year = {2025}
}