Singularity and Dirac dynamics in periodic plasmonic nanostructures

Abstract

We present the formation of a singularity in <i>k</i>-space from a periodic metal-dielectric nanostructure. The singularity originates from the balance between alternating normal and anomalous coupling. By employing the formalism of Dirac dynamics for relativistic quantum particles, we theoretically describe propagation dynamics of surface plasmon polaritons and demonstrate a strong diffraction anomaly (conical-like diffraction) near the singular point.