论文标题
Kagome-Metal Ni3in2s2中的无尽狄拉克节点线
Endless Dirac nodal lines in kagome-metal Ni3In2S2
论文作者
论文摘要
拓扑半学是量子材料的前沿。在多波段电子系统中，拓扑结合可以形成封闭的曲线，称为节点线。在存在旋转轨道耦合和/或对称性操作的情况下，拓扑结节线可以分解成狄拉克/Weyl节点，并引起新型的运输特性，例如手性异常和巨大的异常霍尔效应。最近，在Kagome-Metal CO3SN2S2中观察到了时间反转对称性诱导的Weyl费物，这引发了多体kagome系统中的节点线激发的兴趣。在这里，使用第一原理的计算和基于对称的指标理论，我们在非磁性Ni3 In2 S2中发现了沿kagome层的堆叠方向的六个无尽的淋巴结线，而Kagome平面中的两个节点环。通过角度分辨光发射光谱证实的线性倾向电子结构可在9 t时诱导高达2000％的大磁力。我们的结果建立了多种型kagome金属的多样化拓扑景观。
Topological semimetals are a frontier of quantum materials. In multi-band 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 novel 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 Ni3 In2 S2 . 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 multi-band kagome metals.
