The quantum spin Hall (QSH) effect has attracted extensive research interest because of the potential applications in spintronics and quantum computing, which is attributable to two conducting edge channels with opposite spin polarization and the quantized electronic conductance of 2e2/h. Recently, 2M-WS2, a new stable phase of transition metal dichalcogenides with a 2M structure showing an identical layer configuration to that of the monolayer 1T' TMDs, was suggested to be a QSH insulator as well as a superconductor with critical transition temperature around 8 K. Here, high-resolution angle-resolved photoemission spectroscopy (ARPES) and spin-resolved ARPES are applied to investigate the electronic and spin structure of the topological surface states (TSS) in the superconducting 2M-WS2. The TSS exhibits characteristic spin-momentum-locking behavior, suggesting the existence of long-sought nontrivial Z2 topological states therein. We expect that 2M-WS2 with co-existing superconductivity and TSS might host the promising Majorana bound states.
@article{arxiv.2212.06703,
title = {Direct observation of topological surface state in the topological superconductor 2M-WS2},
author = {Soohyun Cho and Soonsang Huh and Yuqiang Fang and Chenqiang Hua and Hua Bai and Zhicheng Jiang and Zhengtai Liu and Jishan Liu and Zhenhua Chen and Yuto Fukushima and Ayumi Harasawa and Kaishu Kawaguchi and Shik Shin and Takeshi Kondo and Yunhao Lu and Gang Mu and Fuqiang Huang and Dawei Shen},
journal= {arXiv preprint arXiv:2212.06703},
year = {2022}
}