Topological Lifshitz transition of the intersurface Fermi-arc loop in NbIrTe4
Topological Lifshitz transition of the intersurface Fermi-arc loop in NbIrTe4
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NbIrTe4 表面费米弧环的拓扑 Lifshitz 跃迁
DOI：
10.1103/physrevb.102.085126
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发表时间：
2020-08-13
影响因子：
3.7
通讯作者：
Chen, Y. L.
中科院分区：
文献类型：
--
作者：
Ekahana, S. A.;Li, Y. W.;Chen, Y. L.
连接具有相反手性的成对体Weyl点的表面弧（SA）或费米弧是角分辨光电子能谱（ARPES）研究中Weyl半金属的特征。体能带结构的非平凡拓扑保证了这些奇异费米弧的存在，其连接性强烈依赖于表面。理论上提出并实验证实，相对表面的费米弧可以完成一个不寻常的闭合回旋轨道，称为外尔轨道，这导致了各种有趣的输运特性。本文对 II 型 Weyl 半金属 NbIrTe4 的相反终端 (001) 进行了系统的 ARPES 研究，揭示了不同的费米弧连接，从而产生了包含两对 Weyl 点的独特的闭合界面费米弧环构型（结合 SA 的两个投影）。特别是，顶面 ARPES 数据和相应的从头计算表明，拓扑 Lifshitz 转变是通过调节化学势发生的。顶面的 SA 重新布线将外尔节点能级处的界面弧环打开为开放线，挑战了近轨道描述并导致了未探索的场景。我们的结果证明了费米弧连接的内在改变，并提出 NbIrTe4 作为研究费米弧相关现象的潜在平台。
Surface arcs (SAs) or Fermi arcs connecting pairs of bulk Weyl points with opposite chiralities are the signatures of Weyl semimetals in angle-resolved photoemission spectroscopy (ARPES) studies. The nontrivial topology of the bulk band structure guarantees the existence of these exotic Fermi arcs with connectivity that is strongly dependent on the surface. It has been theoretically proposed and experimentally confirmed that Fermi arcs at opposite surfaces can complete an unusual closed cyclotron orbit called a Weyl orbit, which leads to various intriguing transport properties. In this paper, a systematic ARPES study on opposite terminations (001) of type-II Weyl semimetal NbIrTe4 reveals different Fermi arc connections which result in a unique closed intersurface Fermi arc loop configurations (combining both projections of SAs) containing two pairs of Weyl points. In particular, the top surface ARPES data and corresponding ab initio calculation suggests that a topological Lifshitz transition occurs by tuning the chemical potential. SA rewiring on the top surface opens the intersurface arc loop at the Weyl node energy level into an open line, challenging the close-orbit description and leading to an unexplored scenario. Our results demonstrate the intrinsic alteration of Fermi arc connections and propose NbIrTe4 as a potential platform to examine Fermi-arc related phenomenon.