Dirac Line Nodes in Inversion-Symmetric Crystals
Dirac Line Nodes in Inversion-Symmetric Crystals
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DOI：
10.1103/physrevlett.115.036806
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发表时间：
2015-07-17
影响因子：
8.6
通讯作者：
Rappe, Andrew M.
中科院分区：
文献类型：
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作者：
Kim, Youngkuk;Wieder, Benjamin J.;Rappe, Andrew M.
我们提出并表征了一类具有自旋-轨道消失相互作用的新型Z(2)拓扑半金属。所提出的拓扑半金属的特点是存在大块的一维（1D）狄拉克线节点（dln）和二维（2D）近平面态，受到反演和时间反转对称性的保护。我们基于宇称特征值在互反空间的宇称不变量点上发展了Z(2)个不变量来指示dln的存在性。此外，利用第一性原理计算，我们预测通过掺杂非磁性过渡金属原子（如Zn和Pd）， dln会在靠近费米能量的Cu3N中出现，并且dln的投影内部出现二维表面态。这封信包括对自旋轨道相互作用和对称破缺的影响的简要讨论以及对实验意义的评论。
We propose and characterize a new Z(2) class of topological semimetals with a vanishing spin-orbit interaction. The proposed topological semimetals are characterized by the presence of bulk one-dimensional (1D) Dirac line nodes (DLNs) and two-dimensional (2D) nearly flat surface states, protected by inversion and time-reversal symmetries. We develop the Z(2) invariants dictating the presence of DLNs based on parity eigenvalues at the parity-invariant points in reciprocal space. Moreover, using first-principles calculations, we predict DLNs to occur in Cu3N near the Fermi energy by doping nonmagnetic transition metal atoms, such as Zn and Pd, with the 2D surface states emerging in the projected interior of the DLNs. This Letter includes a brief discussion of the effects of spin-orbit interactions and symmetry breaking as well as comments on experimental implications.