钙钛矿结构氧化物(111)表面界面新奇量子现象研究

钙钛矿结构的过渡金属氧化物结构相对简单而且性能优异丰富，其表面或界面更表现出现有理论框架难以理解的奇异性质。特别是在具有六角对称性的(111)表面，钙钛矿结构氧化物可能形成拓扑非平庸的二维电子态；该方向单元胞层周期的超晶格更能给出"双钙钛矿结构"的人工功能材料，其中蕴含着丰富多彩的物理问题，更是设计和构筑复杂功能材料、发展新型电子器件的重要的低维体系。本项目将充分发挥表面物理对表面/界面微观结构的基础研究优势，建立对钙钛矿结构氧化物表面重构与吸附特性及其在不同化学浓度中对外延生长热力学与动力学影响的理解，实现对薄膜和异质界面、超晶格等低维体系在垂直方向具有单元胞层、面内方向具有原子尺度微观结构精度的制备控制；进而紧密结合多尺度、多维度的高分辨率表征与测量手段，并且借助理论计算和分析，理解其中优异电子学特性的起源，并阐明对其进行调控的方法和原理。

Perovskite oxides, with relatively simple lattice structures, possess remarkable properties. On their surfaces or interfaces, even more exotic quantum phenomena emerge. Especially on the (111) surfaces with hexagonal symmetry, topological nontrivial electronic states may exist. And the (111) single-unit-cell superlattices form the double-perovskite functional artificial materials. To realize their applications in novel electronic devices, a series of fundamental physics problems must be solved. Take the advantage of surface physics on the investigations of the surface/interface microstructures, we will study the surface reconstructions and their adsorption properties. Furthermore we will understand the effect of external chemical potential on the epitaxial growth dynamics and kinetics, aiming to achieve the atomic precision of preparation control in both the perpendicular and in-plane directions. Combining with theoretical analyses, high-resolution characterizations and measurements will be carried out for the clarification of the origin of the electronic properties. The goal is to reveal the control methods and mechanisms of the quantum phenomena on perovskite oxide (111) surfaces and interfaces.