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

该奖项的全部或部分资金来自《2021年美国救援计划法案》(公法117-2)。非技术描述：表面极化子是由光(光子)强耦合到界面电偶极子产生的一种混合量子粒子。这些高度受限的纳米光波具有单独存在于单独组件中不存在的紧急特性，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子波，在纳米尺度上捕获光是必不可少的。研究人员将通过堆叠和扭曲特定的2D层来成像空间受限纳米光在一类具有独特原子排列的工程二维(2D)量子设备中的流动。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2D材料和设备中迷人的新物理，并为新型量子纳米光子技术铺平道路。国际和平研究所计划将研究与各种教育和外联活动结合起来，指导K-12年级、本科生和研究生，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为普通公众提供的2D材料和纳米光学的综合推广计划。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)计划联合资助。技术描述：该团队的目标是以前所未有的长度推动光-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)量子设备中出现的拓扑态。主要的焦点是2D范德华异质结构和双声子，这是一个高度可调的拓扑平台，拥有一整套不同的极化子模式(等离子体、声子等)。这可以与远低于衍射极限的入射光子强烈耦合。将采用最先进的扫描近场光学显微镜技术，在所需的长波长光子激发下，直接发射和可视化沿2D扭曲层向下传播到纳米长度的极化电子波。特别值得一提的是，实空间极化子纳米成像使人们能够进入高光子动量空间，这远远超出了传统的远场光学所能达到的水平。利用这种独特的近场扫描技术，项目组计划1)寻找新型拓扑极化子的特征并研究它们在2D量子设备中的内在特性；2)通过调节相对扭角和原位电位移场，探索通过Moiré超晶格势对拓扑极化子的有效控制和操纵；以及3)通过多信使纳米探测器对红外/太赫兹低能尺度上的奇异量子现象进行多维表征，了解新的物理和奇异的量子现象。这项研究有望加深我们对拓扑极化子如何产生并用于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2D扭曲系统中的量子电路等。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.