Authors
Zhijun Wang, Benjamin J Wieder, Jian Li, Binghai Yan, B Andrei Bernevig
Publication date
2019/10/28
Journal
Physical Review Letters
Volume
123
Issue
18
Pages
186401
Publisher
American Physical Society
Description
In recent years, transition metal dichalcogenides (TMDs) have garnered great interest as topological materials. In particular, monolayers of centrosymmetric -phase TMDs have been identified as 2D topological insulators (TIs), and bulk crystals of noncentrosymmetric -phase and have been identified as type-II Weyl semimetals. However, angle-resolved photoemission spectroscopy and STM probes of these semimetals have revealed huge, arclike surface states that overwhelm, and are sometimes mistaken for, the much smaller topological surface Fermi arcs of bulk type-II Weyl points. In this Letter, we calculate the bulk and surface electronic structure of both - and -. We find that - is, in fact, a -nontrivial higher-order TI (HOTI) driven by double band inversion and exhibits the same surface features as - and -. We discover that these surface states are not topologically trivial, as previously characterized by the research that differentiated them …
Total citations
20182019202020212022202320241276882739239