Endless Dirac nodal lines in kagome-metal Ni3In2S2
Endless Dirac nodal lines in kagome-metal Ni3In2S2
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DOI：
10.1038/s41524-022-00838-z
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发表时间：
2022-01
影响因子：
9.7
通讯作者：
Tiantian Zhang;T. Yilmaz;Yilmaz;E. Vescovo;Haoxiang Li;R. Moore;Ho Nyung Lee;H. Miao;S. Mur
中科院分区：
文献类型：
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作者：
Tiantian Zhang;T. Yilmaz;Yilmaz;E. Vescovo;Haoxiang Li;R. Moore;Ho Nyung Lee;H. Miao;S. Mur
拓扑半金属是量子材料的前沿。在多频带电子系统中，拓扑频带交叉可以形成闭合曲线，称为节点线。在自旋轨道耦合和/或自旋破缺操作的存在下，拓扑节线可以破缺成Dirac/Weyl节点，并产生有趣的输运性质，如手征反常和巨反常霍尔效应。最近，在kagome金属Co_3Sn_2S_2中观察到了时间反转破缺诱导的Weyl费米子，引起了人们对多带kagome系统中的单线激发的兴趣。在这里，使用第一性原理计算和基于量子化学的指示理论，我们发现六个无尽的节线沿着堆叠方向的kagome层和两个节环在kagome平面中的Ni 3 In 2S 2。角分辨光电子能谱证实了这种线性双相电子结构，在9 T下产生了高达2000%的大磁电阻。我们的研究结果建立了一个多样的拓扑景观的多频带戈薇金属。
Topological semimetals are a frontier of quantum materials. In multiband electronic systems, topological band crossings can form closed curves, known as nodal lines. In the presence of spin–orbit coupling and/or symmetry-breaking operations, topological nodal lines can break into Dirac/Weyl nodes and give rise to interesting transport properties, such as the chiral anomaly and giant anomalous Hall effect. Recently, the time-reversal symmetry-breaking induced Weyl fermions are observed in a kagome-metal Co3Sn2S2, triggering interests in nodal-line excitations in multiband kagome systems. Here, using first-principles calculations and symmetry-based indicator theories, we find six endless nodal lines along the stacking direction of kagome layers and two nodal rings in the kagome plane in nonmagnetic Ni3In2S2. The linear dipsersive electronic structure, confirmed by angle-resolved photoemission spectroscopy, induces large magnetoresistance up to 2000% at 9 T. Our results establish a diverse topological landscape of multiband kagome metals.