Indexed by: Journal paper

Co-author: Yonghao Yuan, Wei Li, Bin Liu, Peng Deng, Zhilin Xu, Xi Chen, Canli Song, Lili Wang, Ke He, Gang Xu, Xucun Ma, Qi-Kun Xue

Journal: Nano Letters

Included Journals: SCI

Discipline: Science

First-Level Discipline: Physics

Document Type: J

Volume: 18

Issue: 11

Page Number: 7176-7180

Date of Publication: 2018-10-12

Abstract: Quantum spin Hall (QSH) effect is an intriguing phenomenon arising from the helical edge states in two-dimensional topological insulators. We use molecular beam epitaxy (MBE) to prepare FeSe films with atomically sharp nematic domain boundaries, where tensile strains, nematicity suppression, and topological band inversion are simultaneously achieved. Using scanning tunneling microscopy (STM), we observe edge states at the Fermi level that spatially distribute as two distinct strips in the vicinity of the domain boundaries. At the end point of the boundaries, a bound state at the Fermi level is further observed. The topological origin of the edge states is supported by density functional theory calculations. Our findings not only demonstrate a candidate for QSH states but also provide a new pathway to realize topological superconductivity in a single-component film.