CAREER: Exploring chiral edge plasmons in novel two-dimensional materials

非技术描述：在纳米尺度上控制光的流动的能力对于实现用于快速数据处理和宽带信号通信的功能性光学电路是极其重要的。然而，与电子信号不同，在纳米尺度上控制光信号具有挑战性。该项目探索了一类具有原子厚度的新型材料，其中具有纳米级足迹的特殊类型的光可以在这些材料的边缘行进。此外，“纳米级光”的方向和强度都是主动控制的，并且在某些条件下只允许单向传输。这项研究的主要目标是揭示这些“纳米光”的一般特征和关键功能，这可能为其在下一代计算机中的应用铺平道路。该项目为指导和培训高中生、本科生和研究生，特别是来自无代表性少数群体的学生提供了机会。此外，项目组还为公众提供二维材料或光学主题的专题外展活动，并为爱荷华州州立大学的高级实验室课程设计新教材。技术描述：项目组旨在通过探索新型二维材料中的手性边缘等离子体，实现纳米光子信号的终极控制。这些边缘模式是由原子级薄样品中光子和电子之间的耦合形成的，并且可以严格地沿沿着样品边缘传播。通过施加磁场或诱导净布洛赫带Berry曲率与光激发的手征。国家的最先进的散射型扫描近场光学显微镜将提供超快，超小型和宽带成像和光谱的手性边缘等离子体在低温和高磁场。通过这种技术，项目团队计划在基准二维材料-石墨烯和第六族过渡金属二硫属化物中对手性等离子体进行系统研究。主要目标包括表征手性等离子体激元的一般性质，并展示这些模式与纳米级信号控制相关的基本功能。这项研究有望加深我们对二维材料中与电子-电子相互作用和Berry曲率相关的有趣纳米光学物理的理解，彻底改变我们在技术上重要的太赫兹到红外区域的可调谐手性等离子体激元的方法，并建立了手性边缘等离子体作为宽带和主动可调谐的非互易信号通信的新媒体。该奖项反映了NSF的基金会的使命是履行其法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical Description: The capability of controlling the flow of light in the nanoscale is extremely important for realizing functioning optical circuitry for fast data processing and broadband signal communications. Nevertheless, unlike electronic signals, it is challenging to control optical signals in the nanoscale. This project explores a class of novel materials with atomic thicknesses, where a special type of light with nanoscale footprints can travel at the edges of these materials. Moreover, both the direction and the intensity of the “nanoscale light” are actively controlled, and only one-way transport is allowed under certain conditions. The main goal of this research is to uncover the general characteristics and key functionalities of these “nanoscale light”, which could pave the way for its applications in next-generation computers. This project provides opportunities for mentoring and training high-school, undergraduate and graduate students, especially those from unrepresentative minorities in science and engineering. In addition, the project team offers special outreaching activities in the themes of two-dimensional materials or optics for the public and designs new teaching materials for advanced lab courses at Iowa State University.Technical Description: The project team aims to realize the ultimate control of nanophotonic signals by exploring chiral edge plasmons in novel two-dimensional materials. These edge modes are formed by the coupling between photons and electrons in the atomically-thin samples and can propagate strictly along the sample edges. The chirality is introduced either by applying a magnetic field or inducing net Bloch band Berry curvature with optical excitations. State-of-the-art scattering-type scanning near-field optical microscopy will provide ultrafast, ultrasmall and broadband imaging and spectroscopy of chiral edge plasmons at cryogenic temperatures and high magnetic field. With this technique, the project team plans to perform systematic studies of chiral plasmons in the benchmark two-dimensional materials – graphene and group six transition-metal dichalcogenides. The main objectives include characterizing the general properties of chiral plasmons and demonstrating the basic functionalities of these modes related to nanoscale signal control. The research is expected to deepen our understanding of the intriguing nano-optical physics in association with electron-electron interactions and Berry curvature in two-dimensional materials, revolutionize our approach towards tunable chiral plasmonics in the technologically important terahertz to infrared regions, and establish chiral edge plasmons as novel media for nonreciprocal signal communications with broad bandwidth and active tunability.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.