Numerical Analysis of Quantum Plasmonic Metasuraface by Time-Dependent Density Functional Theory

We theoretically investigate optical properties of a quantum plasmonic metasurface composed of metallic nanoparticles that are arranged in a two-dimensional matrix form with a sub-nanometer gap. We employ a time-dependent density functional theory approach to calculate optical properties of the metasurface. They show characteristic features at gap distance smaller than 0.4 nm due to the tunneling currents that flow through the gaps.