Superconductivity in few-layer stanene

By Menghan Liao, Yunyi Zang, Z. Guan, Haiwei Li, Yan Gong, Kejing Zhu, Xiaopeng Hu, Ding Zhang, Yong Xu, Yayu Wang and 4 more. 2017

213 citations recorded by the source corpus.

A single atomic slice of α-tin—stanene—has been predicted to host the quantum spin Hall effect at room temperature, offering an ideal platform to study low-dimensional and topological physics. Although recent research has 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 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. The theory also indicates the existence of a topologically non-trivial band. Our experimental findings open up novel strategies for constructing two-dimensional topological superconductors.Stanene is a single sheet of tin atoms. Here, it is shown that a few stacked layers of stanene can be a superconductor. Changing the thickness of the substrate modifies the form of superconductivity and critical temperature.

Subfields: Atomic and Molecular Physics, and Optics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/c55ea98e353488a2d4ea6e63ef2d2243b75824c2