Single pair of charge-2 Dirac and charge-2Weyl phonons in GeO 2

• Published in: Chinese physics B Vol. 33; no. 10; p. 100301
• Main Authors: He 何, Dong-Chang 东昌, Liu 刘, Jia-Xi 嘉希, Liu 刘, Pei-Tao 培涛, Li 李, Jiang-Xu 江旭, Chen 陈, Xing-Qiu 星秋
• Format: Journal Article
• Language: English
• Published: 01.09.2024
• ISSN: 1674-1056; 2058-3834
• DOI: 10.1088/1674-1056/ad6a08

Abstract The presence of a pair of Weyl and Dirac points (WP–DP) in topological semimetal states is intriguing and sought after due to the effects associated with chiral topological charges. However, identifying these states in real materials poses a significant challenge. In this study, by means of first-principles calculations we predict the coexistence of charge-2 Dirac and charge-2 Weyl phonons at high-symmetry points within a noncentrosymmetric P 4 1 2 1 2 space group. Furthermore, we propose GeO 2 as an ideal candidate for realizing these states. Notably, we observe two distinct surface arcs that connect the Dirac and Weyl points across the entire Brillouin zone, which could facilitate their detection in future experimental investigations. This study not only presents a tangible material for experimentalists to explore the topological properties of WP–DP states but also opens up new avenues in the quest for ideal platforms to study chiral particles.