原子尺度下二维半导体量子缺陷的结构与性质关联解析

Quantum defects in two dimensional semiconductors have emerged as a new platform for single-photon source device research in quantum information technologies. However, to date, it remains challenging to resolve the correlation between the local structure and quantum critical properties, which has been crucial for both the understanding of their physical nature and the property and function control. It requires the correlated analysis from local structure, electronic states and optical properties at the atomic length scale. This project is intended to expand the ultrahigh-resolution optical characterization functionality of scanning tunneling microscope (STM) to realize correlated analysis of the structure, property, and function of materials. By marrying the grating-launched plasmonic nano-light for near-field optical imaging with STM, we can hunt for quantum defects in a single sheet of two-dimensional semiconductor materials through the nanometer-resolved photoluminescence mapping, so that atomically resolved STM characterization the atomic structure, local environment and electronic states of these identified quantum emitters can be initiated and correlated with their excitonic properties. In combination with the STM manipulation on electronic structure we can further explore the way to affect and control the photon emission of these emitters at the single-defect level. This proposed research will unravel the structure-function relationship of quantum defects in two-dimensional materials, and provide new insights into deterministically designing and engineering novel structures that possess quantum critical properties at the atomic level.

二维半导体中量子缺陷的出现为量子信息技术应用提供了新的单光子源器件研究平台。解析这种局域缺陷结构与量子临界性质之间的物理关联是实现性质调控和功能设计的基础，也是目前研究的难点。它需要将材料的原子结构、电子态、以及光学性质紧密关联，实现原子尺度上的关联分析。本项目将进一步拓展扫描隧道显微镜（STM）的光学检测能力，拟利用光栅结构在STM针尖上发射并聚焦等离激元来产生纳米光源来进行近场成像，从而把纳米分辨的光学检测与原子分辨的结构与电子态分析相集成于一体，开展原子尺度下材料结构、性质、以及功能的关联解析研究。项目将通过高分辨近场光学成像来空间定位单片二维半导体量子缺陷，原位表征其原子缺陷结构与电子态，实现单个量子缺陷的结构-功能关联解析。结合STM对缺陷电子结构的操纵能力，探索调控其光学性质的方法。拟通过本项目研究，增进理解二维材料量子缺陷的结构-性质关系，促进原子水平的量子功能结构的设计。

二维半导体材料展现了许多新奇的光电性质和量子临界特性。项目瞄准二维半导体和其量子缺陷的结构解析和光电性质调控，发展基于扫描隧道显微镜系统的高分辨光电性质表征实验技术。在合成的双层WSe2薄膜中发现了和表征了具有量子电荷输运特性的原子缺陷，并实现了其电荷态的精密操纵；借助金属表面功函数的晶面各向异性特性对单层WSe2单晶薄膜实现了不同极性的电荷参杂调控，我们在实验中首次可视化展示了这种剧烈的能带移动和极性反转现象。此外，我们还在二维六方氮化硼薄膜中原位制造原子缺陷并研究其光电性质变化。利用转角堆叠构筑二维摩尔超晶格结构，调节二维WSe2的电子结构和光学性质。这些研究数据和结果为二维材料光电性质调控提供了重要依据，促进了原子尺度材料构效关系理解。