Unconventional Electrodynamics of Nodal Semi-Metals

非技术描述：一种新的材料被命名为“拓扑”材料，因为它们具有独特的性质，在连续变形下保持不变。这个项目研究拓扑金属，以发现它们的不寻常性质。具体地说，该项目将研究拓扑金属在受到外部扰动时的异常光学和电学性质。除了基本利益外，从这项研究中获得的知识可能会影响这些材料在新兴的量子技术学科以及新的光收集和清洁能源技术中的部署，这是一项具有重大社会影响的任务。该项目将涉及不同的本科生群体，他们将接受尖端主题和技术方面的培训，这些主题和技术对于提高他们在STEM领域的代表性至关重要。这个研究小组最近的毕业生在谷歌、亚马逊等公司以及多所大学和国家实验室找到了工作。技术描述：该项目利用一套新兴的纳米光学方法来研究拓扑非平凡导体中的新效应，这些新效应植根于对称破缺和能带结构几何的组合。这个项目解决了关于拓扑系统的物理和纳米尺度电动力学的基本问题。它是通过应用于一类神秘的量子材料的新颖的纳米光学实验来实现的，并将导致新的非线性功能。拟议的实验将为未来其他类型的拓扑材料的纳米光学表征创造一个路线图。该项目还侧重于处理和解决两类主要问题，这两类问题不仅对拓扑学上的非平凡半金属的研究，而且对红外射程的技术应用都有深远的影响。研究生和本科生将接受凝聚态物理、材料科学、扫描探头方法的交叉领域的培训：这是学术界、工业界和政府实验室非常需要的组合。该奖项反映了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。

NON-TECHNICAL DESCRIPTION: A new class of materials has been named as “topological” materials because they have unique properties that remain unchanged under continuous deformations. This project investigates topological metals to uncover their unusual properties. Specifically, the project will investigate unusual optical and electronic properties of topological metals when subjected to external perturbations. Apart from fundamental interest, the knowledge gained from this research could impact the deployment of these materials in the emerging discipline of quantum technology as well as novel light harvesting and clean energy technologies, a task of significant societal impact. The project will involve a diverse group of undergraduate students who will receive training in cutting edge topics and techniques crucial to improving their representation in STEM fields. Recent graduates from this research group found employment in companies such as Google, Amazon as well as in various universities and national laboratories.TECHNICAL DESCRIPTION:The project utilizes a suite of nascent nano-optical methods to investigate novel effects in topologically non-trivial conductors that are rooted in a combination of symmetry breaking and band-structure geometry. This project addresses fundamental questions about the physics and nanoscale electrodynamics of topological systems. It is enabled by novel nano-optical experiments applied to an enigmatic class of quantum materials and will lead to new nonlinear functionalities. The proposed experiments will create a roadmap for future nano-optical characterization of other classes of topological materials. The project furthermore focuses on addressing and resolving the two overarching classes of problems which have deep implications not only for the research in topologically nontrivial semimetals but also for technological applications in the infrared range. Graduate and undergraduate students will be trained in the area at the intersection of condensed matter physics, materials science, scanning probe methods: a combination that is in high demand in academia, industry, and government laboratories.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.