Strongly Coupled Quadrupolar Resonances from Edge-Oriented Plasmonic Nanocube Lattices

Abstract Shaped metal nanoparticles arranged in specific patterns and orientations can induce plasmon coupling, resulting in unique spectral features and highly localized electric fields. Nanocubes (NCs), for example, possess quadrupolar plasmon resonances that give rise to strong optical absorption and high electric field strengths concentrated at the NC corners and edges. While coupling of these resonance modes has been extensively studied in face-oriented NCs, recent experimental achievements have made edge-oriented NCs of particular interest. In this study, we study Ag NCs arranged in various edge-to-edge configurations, including one-dimensional (1D) chains and a two-dimensional (2D) checkerboard lattice. We explore the spectral and near-field properties resulting from the coupling of a NC quadrupolar mode in these different morphological scenarios.