Superconductivity in Few-Layer Stanene

作者：Menghan Liao, Yunyi Zang, Zhaoyong Guan, Haiwei Li, Yan Gong, Kejing Zhu, Hu, Xiao-Peng, ding zhang, Yong Xu, Yayu Wang, Ke He, Xu-Cun Ma, Shoucheng Zhang, Qi‐Kun Xue · 发表于：arXiv (Cornell University) · 年份：2017 · DOI：10.48550/arxiv.1712.03695 · 研究领域：Graphene research and applications、Topological Materials and Phenomena、Quantum and electron transport phenomena

A single atomic slice of α-tin-stanene-has been predicted to host quantum spin Hall effect at room temperature, offering an ideal platform to study low-dimensional and topological physics. While recent research has intensively focused on monolayer stanene, the quantum size effect in few-layer stanene could profoundly change material properties, but remains unexplored. By exploring the layer degree of freedom, we unexpectedly discover superconductivity in few-layer stanene down to a bilayer grown on PbTe, while bulk α-tin is not superconductive. Through substrate engineering, we further realize a transition from a single-band to a two-band superconductor with a doubling of the transition temperature. In-situ angle resolved photoemission spectroscopy (ARPES) together with first-principles calculations elucidate the corresponding band structure. Interestingly, the theory also indicates the existence of a topologically nontrivial band. Our experimental findings open up novel strategies for constructing two-dimensional topological superconductors.