Emergent electronic structure and optical properties in two-dimensional materials

二维材料中的新兴电子结构和光学特性

• 批准号: RGPIN-2018-04596
• 负责人: Ye, Ziliang
• 金额: $ 2.84万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=763134
• 关键词: Emergent; electronic; structure; optical; properties

As a new member of the two dimensional material family, the transition metal dichalcogenide (TMDC) has attracted a lot of interest because many new fascinating physical properties start to emerge at the monolayer limit, such as a direct band gap at the edge of Brillion zone, extraordinarily intense light-matter interaction, access to the valley degree of freedom, and unusually strong Coulomb interaction with reduced screening. In the past, we have discovered a tightly bound exciton stable even at room temperature in TMDC monolayer and successfully controlled its valley coherence using ultrafast light. These extraordinary properties, together with the flexible nature of the material, have triggered tremendous interest in device applications such as flexible screens and touchpads.In this proposed program, our main focus is to explore more emergent phenomena such as the topological Moiré pattern, single photon emitter, and steady Floquet state in 2D TMDCs and related heterostructures towards quantum information applications. We are particularly interested in employing new experimental techniques such as photoinduced force microscopy, ultrafast laser with tunable pulse duration, and high-Q optical micro cavity to study TMDCs in the intense optical field with sub-diffractional spatial resolution. Within the next five years, we will investigate a series of open questions such as the formation mechanism behind the TMDC quantum dot, the impact of Moiré pattern on the optical property of TMDC heterostructures, and the thermalization process of Floquet states. Moreover, we will demonstrate some new control possibilities including the full valley pseudospin manipulation, tunable topological insulator nanostructure array, and the optical induced topologically nontrivial steady Floquet state. A new type of surface-plasmon assisted optical nearfield probe is also in our development plan.The proposed research will have a large impact in physics, material science engineering, and electrical engineering. On the one hand, our study will provide fundamental understanding of topological effects and nonequilibrium physics in solids. The deep insights obtained for TMDCs will help further improve the performance of 2D material/heterostructure based devices. On the other hand, the proposed emergent phenomena are promising to be combined with the spin and valley degrees of freedom to enable scalable quantum information processing in an integrated platform.

作为二维材料家族的新成员，过渡金属二硫属化物（TMDC）引起了人们的广泛兴趣，因为许多新的令人着迷的物理性质开始在单层极限出现，例如在十亿区边缘的直接带隙、异常强烈的光-物质相互作用、进入谷自由度以及异常强的库仑相互作用和减少的屏蔽。过去，我们在TMDC单层和中发现了即使在室温下也能稳定束缚的激子。利用超快光成功地控制了其谷相干性。这些非凡的特性，加上材料的柔性特性，引发了人们对柔性屏幕和触摸板等设备应用的极大兴趣。在这个拟议的项目中，我们的主要重点是探索更多的新兴现象。例如拓扑莫尔图案、单光子发射器和二维 TMDC 中的稳定 Floquet 态以及面向量子信息应用的相关异质结构，我们对采用新的实验技术（例如光诱导力显微镜）特别感兴趣。未来五年内，我们将利用具有可调谐脉冲宽度的超快激光器和高Q值光学微腔来研究具有亚衍射空间分辨率的强光场中的TMDC，例如其形成机制等一系列悬而未决的问题。 TMDC 量子点、莫尔图案对 TMDC 异质结构光学性质的影响以及 Floquet 态的热化过程，此外，我们还将演示一些新的控制可能性，包括全谷赝自旋操纵、可调谐拓扑绝缘体纳米结构阵列和光诱导拓扑非平凡稳定Floquet态也在我们的开发计划中。所提出的研究将对物理学、材料科学工程和物理学产生重大影响。一方面，我们的研究将为固体中的拓扑效应和非平衡物理提供深入的了解，这将有助于进一步提高二维的性能。另一方面，所提出的新兴现象有望与自旋和谷自由度相结合，以在集成平台中实现可扩展的量子信息处理。