1. Quantum spin Hall state in monolayer 1T'-WTe2
- Author
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Tang, Shujie, Zhang, Chaofan, Wong, Dillon, Pedramrazi, Zahra, Tsai, Hsin-Zon, Jia, Chunjing, Moritz, Brian, Claassen, Martin, Ryu, Hyejin, Kahn, Salman, Jiang, Juan, Yan, Hao, Hashimoto, Makoto, Lu, Donghui, Moore, Robert G, Hwang, Chan-Cuk, Hwang, Choongyu, Hussain, Zahid, Chen, Yulin, Ugeda, Miguel M, Liu, Zhi, Xie, Xiaoming, Devereaux, Thomas P, Crommie, Michael F, Mo, Sung-Kwan, and Shen, Zhi-Xun
- Subjects
Fluids & Plasmas ,cond-mat.mes-hall ,Physical Sciences ,cond-mat.mtrl-sci ,Mathematical Sciences - Abstract
A quantum spin Hall (QSH) insulator is a novel two-dimensional quantum state of matter that features quantized Hall conductance in the absence of a magnetic field, resulting from topologically protected dissipationless edge states that bridge the energy gap opened by band inversion and strong spin-orbit coupling. By investigating the electronic structure of epitaxially grown monolayer 1T'-WTe 2 using angle-resolved photoemission (ARPES) and first-principles calculations, we observe clear signatures of topological band inversion and bandgap opening, which are the hallmarks of a QSH state. Scanning tunnelling microscopy measurements further confirm the correct crystal structure and the existence of a bulk bandgap, and provide evidence for a modified electronic structure near the edge that is consistent with the expectations for a QSH insulator. Our results establish monolayer 1T'-WTe 2 as a new class of QSH insulator with large bandgap in a robust two-dimensional materials family of transition metal dichalcogenides (TMDCs).
- Published
- 2017