We grow nearly freestanding single-layer 1T'-WTe2 on graphitized 6H-SiC(0001) by using molecular beam epitaxy (MBE), and characterize its electronic structure with scanning tunneling microscopy / spectroscopy (STM/STS). We demonstrate the existence of topological edge states at the periphery of single-layer WTe2 islands. Surprisingly, we also find a band gap in the bulk and the semiconducting behaviors of the single-layer WTe2 at low temperature, which is likely resulted from an incommensurate charge density wave (CDW) transition. The realization of two-dimensional topological insulators (2D TIs) in single-layer transition metal dichalcogenide (TMD) thus provides a promising platform for further exploration of the 2D TIs' physics and related applications.
@article{arxiv.1703.04042,
title = {Direct Visualization of 2D Topological Insulator in Single-layer 1T'-WTe2},
author = {Zhen-Yu Jia and Ye-Heng Song and Xiang-Bing Li and Kejing Ran and Pengchao Lu and Hui-Jun Zheng and Xin-Yang Zhu and Zhi-Qiang Shi and Jian Sun and Jinsheng Wen and Dingyu Xing and Shao-Chun Li},
journal= {arXiv preprint arXiv:1703.04042},
year = {2017}
}
Comments
12 pages, 5 figures, submitted on Feb 13, 2017 to Phys. Rev. B (Rapid Communications) 2017