A strongly robust type II Weyl fermion semimetal state in Ta3S2
學年 104
學期 2
出版（發表）日期 2016-06-03
作品名稱 A strongly robust type II Weyl fermion semimetal state in Ta3S2
作品名稱（其他語言）
著者 Guoqing Chang; Su-Yang Xu; Daniel S. Sanchez; Shin-Ming Huang; Chi-Cheng Lee; Tay-Rong Chang; Guang Bian; Hao Zheng; Ilya Belopolski; Nasser Alidoust; Horng-Tay Jeng; Arun Bansil; Hsin Lin; M. Zahid Hasan
單位
出版者
著錄名稱、卷期、頁數 Science Advances 2(6), e1600295
摘要 Weyl semimetals are of great interest because they provide the first realization of the Weyl fermion, exhibit exotic quantum anomalies, and host Fermi arc surface states. The separation between Weyl nodes of opposite chirality gives a measure of the robustness of the Weyl semimetal state. To exploit the novel phenomena that arise from Weyl fermions in applications, it is crucially important to find robust separated Weyl nodes. We propose a methodology to design robust Weyl semimetals with well-separated Weyl nodes. Using this methodology as a guideline, we search among the material parameter space and identify by far the most robust and ideal Weyl semimetal candidate in the single-crystalline compound tantalum sulfide (Ta3S2) with new and novel properties beyond TaAs. Crucially, our results show that Ta3S2 has the largest k-space separation between Weyl nodes among known Weyl semimetal candidates, which is about twice larger than the measured value in TaAs and 20 times larger than the predicted value in WTe2. Moreover, all Weyl nodes in Ta3S2 are of type II. Therefore, Ta3S2 is a type II Weyl semimetal. Furthermore, we predict that increasing the lattice by <4% can annihilate all Weyl nodes, driving a novel topological metal-to-insulator transition from a Weyl semimetal state to a topological insulator state. The robust type II Weyl semimetal state and the topological metal-to-insulator transition in Ta3S2 are potentially useful in device applications. Our methodology can be generally applied to search for new Weyl semimetals.
關鍵字 Weyl fermion;Fermi arc;Topology
語言 en_US
ISSN
期刊性質 國外
收錄於 SCI
產學合作
通訊作者
審稿制度 是
國別 USA
公開徵稿
出版型式 ,電子版
相關連結

機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/117382 )