Chiroptical response in coupled plasmonic nanostructures

Abstract

This study delves into the chiroptical response in plasmonic twisted stacks of Au nanostructures with different rotational symmetries. Hybridization of the individual modes excited on each of the stack elements as a function of the twist angle induces a strong chiroptical response under circularly polarized light. The results show that the symmetry of the individual elements affects the charge distribution, modulating the magnitude and spectral position of the hybridized modes. Moreover, multipolar excitations more complex than the ideal in-phase and anti-phase expected hybridizations are found, causing a rich chiroptical response that can be easily adjusted by the twist angle. These systems may be applied as active platforms for detection of molecular chirality or for light polarization.