Superconductivity in few-layer stanene
Superconductivity in few-layer stanene
复制标题
少层锡烯的超导性
DOI：
10.1038/s41567-017-0031-6
复制
发表时间：
2018-04-01
期刊：
影响因子：
19.6
通讯作者：
Xue, Qi-Kun
中科院分区：
文献类型：
--
作者：
Liao, Menghan;Zang, Yunyi;Xue, Qi-Kun
一个单原子切片--α-锡--斯坦烯--被预测在室温下存在量子自旋霍尔效应，这为研究低维和拓扑物理提供了一个理想的平台。虽然最近的研究主要集中在单层单层单烯上，但少层单层单烯中的量子尺寸效应可能会深刻地改变材料的性质，但仍未被探索。通过对层自由度的研究，我们发现了少量单层单层的超导电性，直到在PbTe上生长的双层结构，而体相的α-TiN则不是超导的。通过衬底工程，我们进一步实现了从单带到双带的转变，转变温度翻了一番。用原位角度分辨光电子能谱(ARPES)结合第一性原理计算，阐明了相应的能带结构。该理论还表明存在一个拓扑非平凡带。我们的实验发现为构建二维拓扑超导体开辟了新的途径。
A single atomic slice of alpha-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 alpha-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 angleresolved 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.