2020/12/09 by Peng Zhang, Ryo Noguchi, Kenta Kuroda +14 · 85 citations
Materials Science · Physics and Astronomy · #2D Materials and Applications #Band gap #Chemical and Physical Properties of Materials #Dirac (video compression format) #Insulator (electricity) #Photoemission spectroscopy #Semimetal #Surface states #Topological Materials and Phenomena #Topological insulator #Topology (electrical circuits) #cond-mat.mtrl-sci
paper · pdf · doi:10.1038/s41467-020-20564-8
published in Nature Communications 12(1), 406 (Nature Portfolio) · 8 pages, 4 figures. Accepted by Nature Communications
arxiv created 2020/12/09 · openalex created_date 2020/12/21 · openalex publication_date 2021/01/18 · arxiv updated 2021/01/20 · openalex updated_date 2026/08/06
Abstract A quantum spin Hall (QSH) insulator hosts topological states at the one-dimensional (1D) edge, along which backscattering by nonmagnetic impurities is strictly prohibited. Its 3D analogue, a weak topological insulator (WTI), possesses similar quasi-1D topological states confined at side surfaces. The enhanced confinement could provide a route for dissipationless current and better advantages for applications relative to strong topological insulators (STIs). However, the topological side surface is usually not cleavable and is thus hard to observe. Here, we visualize the topological states of the WTI candidate ZrTe 5 by spin and angle-resolved photoemission spectroscopy (ARPES): a quasi-1D band with spin-momentum locking was revealed on the side surface. We further demonstrate that the bulk band gap is controlled by external strain, realizing a more stable WTI state or an ideal Dirac semimetal (DS) state. The highly directional spin-current and the tunable band gap in ZrTe 5 will provide an excellent platform for applications.