CAREER: Towards Novel Twist Polaritonics in 2D Crystals and Devices

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。非技术描述：表面极化子是一种由光（光子）与界面电偶极子强耦合而产生的混合量子粒子。这些高度受限的纳米光波具有突发性特性，这些特性在单独的组件中并不存在，这使它们有可能实现用于传感、通信和信息处理的新型电路。为了产生和操纵这些极化波，必须在纳米尺度上捕获光。研究人员将通过堆叠和扭曲特定的二维层，在一类具有独特原子排列的工程二维（2D）量子器件中对空间受限纳米光的流动进行成像。这项研究将揭示在这些独特结构中传播纳米光波的新特征。该团队希望利用极化波来揭示二维材料和设备中迷人的新物理学，并为新型量子纳米光子技术铺平道路。PI计划将研究与各种教育和推广活动结合起来，以指导K-12、本科和研究生阶段的学生，特别是那些来自代表性不足的少数群体的学生。该团队还将参与由佛罗里达州立大学和国家强磁场实验室联合提供的二维材料和纳米光学的综合推广项目。该项目由材料研究部（DMR）的电子与光子材料（EPM）和凝聚态物理（CMP）项目共同资助。技术描述：该团队的目标是在前所未有的长度尺度上推动光-物质相互作用的极限，并利用发射的极化波来阐明和控制二维（2D）量子器件中的紧急拓扑状态。主要的焦点是二维范德华异质结构和扭转电子学，这是一个高度可调的拓扑平台，拥有一整套不同的极化模式（等离子体，声子等），可以与远低于衍射极限的入射光子强耦合。最先进的扫描近场光学显微镜技术将被用于直接发射和可视化极化波，因为它们沿着二维扭曲层在所需的长波长光子激发下传播到纳米长度尺度。特别是，实空间极化纳米成像可以获得远超传统远场光学所能达到的高光子动量空间。利用这种独特的扫描近场技术，项目团队计划1)寻找新型拓扑极化电子学的特征，并研究它们在二维量子器件中的内在特征；2)通过调节相对扭转角和原位电位移场，探索通过莫尔超晶格势对拓扑极化子的有效控制和操纵；3)通过多信使纳米探针在多个维度上的表征，了解红外/太赫兹低能尺度下的新物理和奇异量子现象。这项研究有望加深我们对拓扑极化子如何产生和利用来探测量子固体的理解，并利用长寿命的无耗散纳米光流用于未来的应用，包括量子传感和通信，拓扑激光和二维扭曲系统中的量子电路等。该奖项反映了美国国家科学基金会的法定使命，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。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Nontechnical Description: Surface polaritons are a type of hybrid quantum particles resulting from light (photons) strongly coupled to interfacial electric dipoles. These highly confined nano-light waves have emergent properties that do not exist in the separate components alone, giving them the potential to realize novel circuitry for sensing, communications, and information processing. It is essential to trap light at the nanoscale to generate and manipulate these polaritonic waves. The investigators will image the flow of spatially confined nano-light in a class of engineered two-dimensional (2D) quantum devices with a unique atomic arrangement by stacking and twisting specific 2D layers. This research will uncover the novel characteristics of propagating nano-light waves that occur within these unique structures. The team expects to harness polaritonic waves to shed light on the fascinating new physics in 2D materials and devices and pave the way for new types of quantum nano-photonic technologies. The PI plans to integrate research with various education and outreach activities to mentor students at the K-12, undergraduate and graduate levels, especially those from underrepresented minority groups. The team will also participate in integrated outreach programs on 2D materials and nano-optics for the general public offered jointly by Florida State University and the National High Magnetic Field Laboratory. This project is jointly funded by the Electronic and Photonic Materials (EPM) and the Condensed Matter Physics (CMP) programs of the Division of Materials Research (DMR).Technical Description: The team aims to push the limits of light-matter interactions at unprecedented length scales and employ the emitted polaritonic waves to elucidate and control emergent topological states in two-dimensional (2D) quantum devices. The primary focus is on 2D van der Waals heterostructures and twistronics, a highly tunable topological platform that hosts a full suite of different polaritonic modes (plasmons, phonons, etc.) that can strongly couple with the incident photons far below the diffraction limit. State-of-the-art scanning near-field optical microscopy techniques will be carried out to directly launch and visualize polaritonic waves as they travel along 2D twisted layers down to the nanometer length scale at the desired long-wavelength photon excitations. In particular, real-space polaritonic nano-imaging grants access to the high photon momentum space that is far beyond what is attainable with conventional far-field optics. With this unique scanning near-field technique, the project team plans to 1) look for signatures of novel topological polaritonics and investigate their intrinsic characters in 2D quantum devices; 2) explore effective control and manipulation of topological polaritons through the moiré superlattice potential by tuning the relative twist angles and in situ electrical displacement fields; and 3) understand the new physics and exotic quantum phenomena at the infrared/terahertz low energy scales through multi-messenger nano-probe characterizations across multiple dimensions. The research is expected to deepen our understanding of how the topological polaritons can be generated and utilized to probe quantum solids, and harnessing long-lived dissipation-less flow of nano-light for future applications including quantum sensing and communication, topological lasers and quantum circuitry in 2D twisted systems and beyond.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.