Insight into the Topological Nodal Line Metal YB<sub>2</sub> with Large Linear Energy Range: A First-Principles Study

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...

Full description

Bibliographic Details
Main Authors: Yang Li, Jihong Xia, Rabah Khenata, Minquan Kuang
Format: Article
Language:English
Published: MDPI AG 2020-08-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/13/17/3841
Description
Summary: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, YB<sub>2</sub>, with phase stability and a <i>P6/mmm</i> space group, and studied the phonon dispersion, electronic structure, and topological nodal line signatures via first principles. The computed results show that YB<sub>2</sub> is a metallic material with one pair of closed nodal lines in the <i>k<sub>z</sub></i> = 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, YB<sub>2</sub> 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.
ISSN:1996-1944