CAREER: Nanoscopy Of Surface States In Two-Dimensional Materials

快速的技术进步往往是由新材料和物理现象的发现所驱动的。二维层状材料在现代材料研究中表现出一些最引人注目的物理现象，并有望用于从柔性电子到能量收集和存储到生物工程的广泛的未来设备和技术应用。这个项目探讨了在纳米尺度上由于协调一致的多体相互作用而产生的层状二维晶体上出现的电子和激子表面态。这些调查将推进我们的表面状态，支配下一代纳米光电子器件的电子和光学特性和二维纳米激光器的可行性的基本理解。这些研究活动是一个综合教育计划的一部分，以进一步高中，本科和研究生的纳米科学和纳米光学学习在大亚特兰大地区。这项研究还与推广活动相结合，以加强当地高中物理教师和学生的教育和培训，以及与社区推广计划，针对非洲移民学生/家庭和非洲裔美国青年在亚特兰大地区的教育经验。技术摘要：这个CAREER奖的研究部分探索了电子和激子表面状态的货车德瓦尔斯层状二维晶体使用国家的最先进的远，场和纳米近场光谱学。本研究的目标是：（1）了解二维系统中表面态、金属表面态、导电表面态和拓扑保护表面态的基本性质;（二）了解激子的性质（带电和中性）在岛边缘和缺陷，并阐明激子二维材料和表面等离子体之间的耦合机制，特别是激子货车德瓦尔斯异质结构中的受激发射机制，该异质结构通过垂直堆叠原子薄材料制成;以及（iii）在低维物理学领域中扩展光学、红外和太赫兹散射扫描近场光学显微镜方法的范围和效用。拟议研究的结果将推进我们对控制二维涌现材料系统的电子和光学性质的表面态的基本理解，并将导致奇异的多体物理学和自旋电子学的应用，实用的量子计算机和固体-该奖项反映了NSF的法定使命，并通过使用基金会的智力价值进行评估，被认为值得支持和更广泛的影响审查标准。

Nontechnical Abstract: Rapid technological advances are often driven by the discovery of new materials and physical phenomena. Two-dimensional layered materials exhibit some of the most striking physical phenomena in modern materials research and hold promise for a wide range of future devices and technological applications from flexible electronics to energy harvesting and storage to bio-engineering. This project explores emergent electronic and excitonic surface states on layered two-dimensional crystals that arise due to the concerted many-body interactions at nanometer length scales. These investigations will advance our fundamental understanding of surface states that govern the electronic and optical properties of the next-generation nano-optoelectronic devices and the feasibility of two-dimensional nanolasers. These research activities are part of an integrated education plan to further high school, undergraduate and graduate students' nanoscience and nano-optics learning in the greater Atlanta area. The research is also integrated with outreach activities to enhance the education and training of local high school physics teachers and students as well as with community outreach plans that targets the educational experience of African immigrant students/families and African American youth in the Atlanta area.Technical Abstract: The research part of this CAREER award explores the electronic and excitonic surface states on van der Waals layered two-dimensional crystals using state-of-the-art far-field and nanoscale near-field spectroscopy. The goals of this research are: (i) understand the fundamental properties of surface states in two-dimensional systems, metallic and conducting surfaces states and topologically protected surface states; (ii) understand the properties of excitons (charged and neutral) at island edges and defects and elucidate the coupling mechanism between excitonic two-dimensional materials and surface plasmons, in particular the mechanism of stimulated emission in excitonic van der Waals heterostructures made by vertically stacking atomic thin materials; and (iii) expand the scope and utility of optical, infrared and terahertz scattering scanning near-field optical microscopy approaches in the field of low-dimensional physics. The results of the proposed research will forward our underlying understanding of surface states that control the electronic and optical properties of two-dimensional emergent material systems and will lead to exotic many-body physics and applications in spintronics, practical quantum computers and solid-state quantum photonics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.