Advancements of Intense Terahertz Field Focusing on Metallic Nanoarchitectures for Monitoring Hidden Interatomic Gas-Matter Interactions.

With the advancements of nanotechnology, innovative photonic designs coupled with the functional materials provide a unique way to acquire, share, and respond effectively to information. We found that the simple deposition of a 30 nm-thick palladium nanofilm on a terahertz metasurface chip with a 14 nm-wide effective nanogap of asymmetric materials and geometries allows the tracking of both interatomic and interfacial gas-matter interactions, including gas adsorption, hydrogenation (or dehydrogenation), metal phase changes, and unique water-forming reactions. Combinatorial analyses by simulation and experimental measurements demonstrated our distinct nanostructures, which led to significant light-matter interactions and corresponding terahertz absorption in a real-time, highly repeatable, and reliable manner. The complex lattice dynamics and intrinsic properties of metals influenced by hydrogen gas exposure were also thoroughly examined using systematically controlled ternary gas mixture devices that mimic normal temperature and pressure. Furthermore, we utilized the novel degrees of freedom to analyze various physical phenomena, and thus, introduced analytical methods that enabled the tracking of unknown hidden stages of water-forming reactions resulting in water growth. A single exposure of the wave spectrum emphasizes the robustness of the proposed terahertz nanoscopic probe, bridging the gap between fundamental laboratory research and industry. This article is protected by copyright. All rights reserved.