Indexed by: Journal paper

First Author: Tao Deng

Correspondence Author: Yulin Chen,Zhongkai Liu

Co-author: Gang Xu,Yanfeng Guo,Zhi Liu,Lexian Yang,Makoto Hashimoto,Donghui Lu,Eli Rotenberg,Aaron Bostwick,Chris Jozwiak,Kui Huang,Chengwei Wang,Haifeng Yang,Shengtao Cui,Aiji Liang,Junyi He,Hao Su,Cheng Chen

Journal: Physical Review B

Included Journals: SCI

Discipline: Science

First-Level Discipline: Physics

Document Type: J

Volume: 102

Issue: 4

Page Number: 45106

ISSN No.: 2469-9950

Date of Publication: 2020-07-06

Impact Factor: 4.036

Abstract: There has been an upsurge in the discovery of topological quantum materials, where various topological insulators and semimetals have been theoretically predicted and experimentally observed. However, very few of them contain silicon, the most widely used element in the electronics industry. Recently, ternary compound CaAl2Si2 has been predicted to be a topological Dirac semimetal, hosting Lorentz-symmetry-violating quasiparticles with a strongly tilted conical band dispersion. In this work, by using high-resolution angle-resolved photoemission spectroscopy, we investigated the comprehensive electronic structure of CaAl2Si2. A pair of topological Dirac crossings is observed along the kz direction, in good agreement with the ab initio calculations, confirming the topological Dirac semimetal nature of the compound. Our study expands the topological material family on Si-containing compounds, which have great application potential in realizing low-cost, nontoxic electronic devices with topological quantum states.