SrSi材料类中的可调谐双外尔费米子半金属态。

Tunable double-Weyl Fermion semimetal state in the SrSi materials class.

作者信息

Singh Bahadur, Chang Guoqing, Chang Tay-Rong, Huang Shin-Ming, Su Chenliang, Lin Ming-Chieh, Lin Hsin, Bansil Arun

机构信息

SZU-NUS Collaborative Center and International Collaborative Laboratory of 2D Materials for Optoelectronic Science & Technology, Engineering Technology Research Center for 2D Materials Information Functional Devices and Systems of Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, ShenZhen, 518060, China.

Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore, 117546, Singapore.

出版信息

Sci Rep. 2018 Jul 12;8(1):10540. doi: 10.1038/s41598-018-28644-y.

DOI:10.1038/s41598-018-28644-y

PMID:30002388

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6043586/

Abstract

We discuss first-principles topological electronic structure of noncentrosymmetric SrSi materials class based on the hybrid exchange-correlation functional. Topological phase diagram of SrSi is mapped out as a function of the lattice constant with focus on the semimetal order. A tunable double-Weyl Fermion state in SrCaSi and SrBaSi alloys is identified. Ca doping in SrSi is shown to yield a double-Weyl semimetal with a large Fermi arc length, while Ba doping leads to a transition from the topological semimetal to a gapped insulator state. Our study indicates that SrSi materials family could provide an interesting platform for accessing the unique topological properties of Weyl semimetals.

摘要

我们基于杂化交换关联泛函讨论了非中心对称SrSi材料类的第一性原理拓扑电子结构。绘制了SrSi的拓扑相图，该相图是晶格常数的函数，重点关注半金属序。在SrCaSi和SrBaSi合金中识别出了一种可调谐的双外尔费米子态。研究表明，在SrSi中掺入Ca会产生具有大费米弧长的双外尔半金属，而掺入Ba则会导致从拓扑半金属向带隙绝缘体态的转变。我们的研究表明，SrSi材料家族可以为探索外尔半金属独特的拓扑性质提供一个有趣的平台。