A topological Hund nodal line antiferromagnet

• Published in: Nature communications Vol. 15; no. 1; pp. 7052 - 10
• Main Authors: Yang, Xian P., Yao, Yueh-Ting, Zheng, Pengyu, Guan, Shuyue, Zhou, Huibin, Cochran, Tyler A., Lin, Che-Min, Yin, Jia-Xin, Zhou, Xiaoting, Cheng, Zi-Jia, Li, Zhaohu, Shi, Tong, Hossain, Md Shafayat, Chi, Shengwei, Belopolski, Ilya, Jiang, Yu-Xiao, Litskevich, Maksim, Xu, Gang, Tian, Zhaoming, Bansil, Arun, Yin, Zhiping, Jia, Shuang, Chang, Tay-Rong, Hasan, M. Zahid
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 15.08.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/119/2792; 639/766/119/995; Antiferromagnetism; Brillouin zones; Bulk density; Correlation; Density functional theory; electronic properties and materials; Humanities and Social Sciences; Magnetism; MATERIALS SCIENCE; Mean field theory; multidisciplinary; Photoelectric emission; Physics; Science; Science (multidisciplinary); Spectroscopy; State-of-the-art reviews; Symmetry; topological matter; Topology
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-51255-3

The interplay of topology, magnetism, and correlations gives rise to intriguing phases of matter. In this study, through state-of-the-art angle-resolved photoemission spectroscopy, density functional theory, and dynamical mean-field theory calculations, we visualize a fourfold degenerate Dirac nodal line at the boundary of the bulk Brillouin zone in the antiferromagnet YMn 2 Ge 2 . We further demonstrate that this gapless, antiferromagnetic Dirac nodal line is enforced by the combination of magnetism, space-time inversion symmetry, and nonsymmorphic lattice symmetry. The corresponding drumhead surface states traverse the whole surface Brillouin zone. YMn 2 Ge 2 thus serves as a platform to exhibit the interplay of multiple degenerate nodal physics and antiferromagnetism. Interestingly, the magnetic nodal line displays a d -orbital dependent renormalization along its trajectory in momentum space, thereby manifesting Hund’s coupling. Our findings offer insights into the effect of electronic correlations on magnetic Dirac nodal lines, leading to an antiferromagnetic Hund nodal line. The interplay of magnetism, various symmetries and correlations can lead to intriguing physics in the solid state. Here, the authors report signatures of a Hund nodal line in the antiferromagnet YMn 2 Ge 2 .