Large Fermi arc and robust Weyl semimetal phase in Ag2S
Large Fermi arc and robust Weyl semimetal phase in Ag2S
复制标题
Ag2S 中的大费米弧和坚固的 Weyl 半金属相
DOI：
10.1103/physrevb.100.205117
复制
发表时间：
2019
影响因子：
3.7
通讯作者：
Yu Rui
中科院分区：
文献类型：
--
作者：
Wang Zhenwei;Luo Kaifa;Zhao Jianzhou;Yu Rui
三维狄拉克和魏尔半金属在凝聚态物理和材料科学中引起了广泛的兴趣。在此，基于第一性原理计算和对称性分析，我们报道了${\mathrm{Ag}}_{2}\mathrm{S}$具有$P{2}_{1}{2}_{1}{2}_{1}$对称性是无自旋-轨道耦合（SOC）的拓扑狄拉克半金属。每一个狄拉克点都是由两个具有相同手性的Weyl点在动量空间中重叠而成。考虑到SOC后，每个狄拉克点被分成两个Weyl点。手性相反的Weyl点在动量空间中相距很远。因此，Weyl对在${\ mathm {Ag}}_{2}\ mathm {S}$化合物中不易湮灭且具有鲁棒性，这也导致了材料表面上的长费米弧。讨论了Weyl点对应变的鲁棒性。
Three-dimensional Dirac and Weyl semimetals have attracted widespread interest in condensed matter physics and material science. Here, based on the first-principle calculations and symmetry analysis, we report that ${\mathrm{Ag}}_{2}\mathrm{S}$ with $P{2}_{1}{2}_{1}{2}_{1}$ symmetry is a topological Dirac semimetal in the absence of spin-orbit coupling (SOC). Every Dirac point is composed of two Weyl points with the same chirality overlapping in the momentum space. After taking the SOC into consideration, each Dirac point is split into two Weyl points. The Weyl points with the opposite chirality are far from each other in the momentum space. Therefore, the Weyl pairs are not easy to annihilate and are robust in the ${\mathrm{Ag}}_{2}\mathrm{S}$ compound, which also leads to long Fermi arcs on material surfaces. The robustness of the Weyl points against the strain is discussed.