Insight into the Topological Nodal Line Metal YB2 with Large Linear Energy Range: A First-Principles Study

Materials

Jihong Xia¹  Yang Li¹  Rabah Khenata²  Minquan Kuang³ 

[1] Department of Physics, Chongqing University of Arts and Sciences, Chongqing 402160, China;Laboratoire de Physique Quantique de la Matiere et de Modelisation Mathematique (LPQ3M), Universite de Mascara, Mascara 29000, Algeria;School of Physical Science and Technology, Southwest University, Chongqing 400715, China;

关键词: YB₂;    linear band crossing;    topological metal;    spin–orbit coupling;    phonon dispersion;    electronic structure;   

DOI  :  10.3390/ma13173841

来源: DOAJ

【 摘 要 】

The presence of one-dimensional (1D) nodal lines, which are formed by band crossing points along a line in the momentum space of materials, is accompanied by several interesting features. However, in order to facilitate experimental detection of the band crossing point signatures, the materials must possess a large linear energy range around the band crossing points. In this work, we focused on a topological metal, YB₂, with phase stability and a P6/mmm space group, and studied the phonon dispersion, electronic structure, and topological nodal line signatures via first principles. The computed results show that YB₂ is a metallic material with one pair of closed nodal lines in the k_z = 0 plane. Importantly, around the band crossing points, a large linear energy range in excess of 2 eV was observed, which was rarely reported in previous reports that focus on linear-crossing materials. Furthermore, YB₂ has the following advantages: (1) An absence of a virtual frequency for phonon dispersion, (2) an obvious nontrivial surface state around the band crossing point, and (3) small spin–orbit coupling-induced gaps for the band crossing points.

【 授权许可】

Unknown