Unconventional Electrodynamics of Nodal Semi-Metals

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.