硅表面二维Mott绝缘体超导性质研究

未掺杂的铜酸盐是Mott绝缘态，通过引入空穴或电子掺杂实现超导转变，然而由于结构和性质的复杂性，至今对铜酸盐高温超导体的超导机制尚未有达成广泛共识。一个结构简单性质类似的体系将有助于推动高温超导机制研究的发展。第IV主族元素在硅表面形成的√3X√3结构是理想的结构简单能带单一的二维Mott绝缘体，近期我们利用调制掺杂的方法发现了空穴掺杂的Sn√3X√3超导性质，然而目前对该体系的超导性质认识还不全面。本项目拟利用扫描隧道显微术（STM）研究掺杂和电子强关联在该体系超导转变中的作用，将有助于我们更好的理解非常规超导机制。另外，电子强关联的六角晶格本认为是探寻手性超导的理想平台，由于时间反演对称性破缺手性超导具有重要的基础研究价值（如马约拉纳费米子）和未来应用潜力，相比于其他潜在的手性超导体该体系具有更强的超导态，因此超导配对对称性研究也是本项目的重要内容。

Undoped cuprates are Mott insulating, which realize superconducting transition by introducing holes or electron doping. However, due to the complexity of structure and electronic properties, there still is no consensus regarding the precise mechanism of cuprate superconductivity. A system with simple structure and similar properties will help to promote the development of the mechanism of high temperature superconductivity. The √ 3x √ 3 structure formed by group IV elements on the silicon surface is an ideal two-dimensional Mott insulator with simple structure and single energy band surface state. Recently, we found the superconducting properties of hole doped Sn √ 3x √ 3 by using the method of modulation doping. However, the understanding of the superconducting properties of this system is not comprehensive at present. This project intends to use scanning tunneling microscopy (STM) to study the role of doping and electron strong correlation in the superconducting transition of the system, which will help us better understand the mechanism of unconventional superconductivity. In addition, the hexagonal lattice with strong electron correlation is considered to be an ideal platform to pursue chiral superconductors. Due to the breaking of time inversion symmetry, chiral superconductors have important basic research value (e.g. Majorana Physics) and future application potential. Compared with other potential chiral superconductors, this system has stronger superconducting states. Therefore, the study of superconducting pairing symmetry in this system is also content of this project.