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
Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA.
Department of Physics, National Cheng Kung University, Tainan, Taiwan.
Nat Commun. 2024 Aug 15;15(1):7052. 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 YMnGe. 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. YMnGe 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.
拓扑、磁性和关联之间的相互作用产生了有趣的物质相。在本研究中，通过先进的角分辨光电子能谱、密度泛函理论和动态平均场理论计算，我们在反铁磁体YMnGe的体布里渊区边界处可视化了一条四重简并狄拉克节线。我们进一步证明，这种无带隙的反铁磁狄拉克节线是由磁性、时空反演对称性和非对称晶格对称性共同作用形成的。相应的鼓面表面态贯穿整个表面布里渊区。因此，YMnGe成为展示多种简并节线物理与反铁磁性相互作用的平台。有趣的是，磁性节线在动量空间中的轨迹上表现出与d轨道相关的重整化，从而体现了洪德耦合。我们的发现为电子关联对磁性狄拉克节线的影响提供了见解，从而产生了反铁磁洪德节线。
