Exotic Coupling Between Plasmonic Nanoparticles Through Geometric Configurations

Coupled plasmonic systems are of great interest and have many applications such as information processing and sensing. By choosing proper geometric configurations of coupled plasmonic systems, one can obtain various optical properties. However, some interesting and important effects could not be described by earlier methods. We develop an improved method for coupled plasmonic nanoparticle systems that maps geometric configurations to optical properties more accurately. With the improved method, we realize a low-loss cavity of metallic nanoparticles through a proper geometric configuration, and we find a limit to the loss in the metallic nano-cavity. We also use this method to realize an exceptional point and exceptional nexus in a hybrid plasmonic system. Finally, we predict asymmetric coupling, which leads to chirality and directional energy transfer.