Technical Description: The research component of this CAREER award aims to develop a new class of solid-state materials exhibiting strong, tunable electric and magnetic resonances at visible frequencies. Such materials have the potential to transcend the optical properties of naturally-occurring media, enabling unique optical excitation of magnetic modes, tunable refractive indices, and controllable optical chirality. These metamaterials are designed using two symmetry-broken "meta-atoms" as building blocks, including a metal-coated dielectric nanocrescent and a close-packed trimer of metallic nanoparticles. They are expected to enable a controlled electric and magnetic resonance for unique refractive index tenability, and lead to chirality and optical activity as a result of a strong interaction between electric and magnetic dipoles. Theoretical calculations guide meta-atom design, whose synthesis is through a combination of bottom-up and top-down assembly. Optical and electron spectroscopy techniques are used to characterize the electric and magnetic modes of the proposed metamaterials with nanometer-scale resolution. Non-technical Description: The color of objects, the efficiency of solar cells, and the physics of fiber-optical communications are all interconnected by the way light interacts with materials. Light is composed of oscillating electric and magnetic fields, but at visible frequencies, most materials only interact with the electric component. If materials could also interact with magnetic component, there would be profound implications in science and technologies. This project is designed to develop a new class of solid-state materials that interact with both the electric and magnetic component of light. These materials are constructed from nanoscale metal and dielectric building blocks exhibiting geometric asymmetry. In addition, cross-disciplinary education activities introduce the public to these exotic and enabling materials. The PI engages in undergraduate and graduate mentoring, K-12 outreach, conference symposia organization, and writing a textbook. Further, the PI develops a nano-optics art exhibit for local museums, featuring the history of nano in art, as well as the exotic and enabling science and applications of symmetry-broken nanostructures in modern life.
