狄拉克线节点在反转对称晶体中。

Dirac Line Nodes in Inversion-Symmetric Crystals.

机构信息

The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA.

Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6396, USA.

出版信息

Phys Rev Lett. 2015 Jul 17;115(3):036806. doi: 10.1103/PhysRevLett.115.036806.

DOI:10.1103/PhysRevLett.115.036806

PMID:26230819

Abstract

We propose and characterize a new Z2 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 Z2 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 Cu_{3}N 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.

摘要

我们提出并描述了一个新的具有零自旋轨道相互作用的 Z2 类拓扑半金属。所提出的拓扑半金属的特征在于存在体一维（1D）狄拉克线节点（DLN）和二维（2D）近平面表面态，这些表面态受反转和时间反转对称性保护。我们基于在倒易空间中的宇称不变点处的宇称本征值，发展了决定 DLN 存在的 Z2 不变量。此外，我们通过使用第一性原理计算，预测通过掺杂非磁性过渡金属原子（如 Zn 和 Pd）在 Cu3N 中在费米能级附近出现 DLN，而 2D 表面态则出现在 DLN 的投影内部。这封信还简要讨论了自旋轨道相互作用和对称破缺的影响，并评论了实验意义。