新型二维异质结结构中电子自旋特性的调控

The project will focus on the growth, fabrication, interface engineering and basic physics in new-type ultra-thin semiconductor heterostructures. We will try to grow and fabricate an atomically-thin commonly-used semiconductor heterostructures with controllable interface configurations and novel Van der Waals heterostructure in two-dimensional atomic crystal. We will reveal the effect of chemical bonding and charge transfering at the interface (or the substrate) on the band structure of the host materials; and develop various routes to tailor the energy band structures, interface charge polarization and hybridization between different atoms; and explore the possible ways of enhanced spin-orbit coupling effects and realization of topological phase. Also we will work out a practical scheme to generate spin (valley) polarized current and pure spin (valley) current and find out the driving mechanism of the external fields. We will study how the electron-electron interaction and electron-phonon interaction affect the photoelectric process and spin decoherence, explore the controlling methods by the external field and provide a physical basis for construction next generation of high-density integrated, high-speed, low-power semiconductor spintronic devices.

本项目将围绕新型半导体异质结界面结构的生长、制备和基础物理过程开展理论与实验两方面的研究。生长并制备出超薄的、原子尺度界面可控的主流半导体的异质结结构和新型二维原子晶体范德华异质结，揭示界面处（或于衬底）微观化学成键和电荷转移对材料能带结构的影响，研究剪裁能带结构以及异质界面处电荷极化和轨道杂化的调控方法，探索增强自旋轨道耦合效应和实现拓扑相的可能途径。研究产生自旋（谷）极化电流、纯自旋（谷）流的实际方案、以及外场的驱动机制。研究此类系统中电子-电子互作用、电子-声子互作用对光电过程、自旋退相干的影响及外场调控方法，为构造下一代高密度集成、高速、低功耗的半导体新型自旋量子器件提供物理基础。

近年来，新型二维异质结结构引起了理论与实验物理学研究的强烈兴趣。新型二维异质结结构包括基于二维材料的范德瓦尔斯异质结，以及半导体超薄极性界面异质结。前者构成未来柔性功能器件基础，而后者则因为10MV/cm量级的内建电场强度和0-2eV范围的带隙调控能力显著区别于传统异质结界面。本项目围绕新型半导体二维量子体系中自旋特性和调控开展研究，以基于半导体超薄量子阱、二维材料异质结（石墨烯、MoS2 等）为研究平台，弄清自旋极化、退相干物理机理，探索新奇量子相，构造基于新型半导体异质结构的自旋电子原理器件。项目执行期间共发表SCI收录论文113篇，其中包括Nature Nanotech. 1篇，Nature communication 6篇， Phys. Rev. Lett. 4篇， Nano Lett. 6篇，ACS NANO 5篇， Adv. Mat. 1篇， Chem. Soc. Rev. 等综述文章5篇。项目按照既定研究计划切实执行，达成既定总体目标。