反強磁性体において実現した室温での巨大異常ネルンスト効果——磁気ワイルフェルミオンが織りなすトポロジ力ル現象——

摘要

Here, we report a striking discovery of large spontaneous Hall and Nernst effects at room temperature in the antiferromagnet Mn_3Sn. The Hall and Nernst signals are found more than 100 times larger than what would be expected based on the magnetization. Our experiments demonstrate that the large anomalous Hall and Nernst signals arise from the Berry curvature associated with the Weyl points near the Fermi energy.