Plasmon dromions in a metamaterial via plasmon-induced transparency

We propose a scheme to realize a giant Kerr nonlinearity and create stable high-dimensional nonlinear plasmon polaritons via plasmon-induced transparency (PIT) in a metamaterial, which is constructed by an array of unit cell consisting of a cut-wire and a pair of varactor-loaded split-ring resonators. We show that, due to the PIT effect and the nonlinearity contributed by the varactor, the system may possess very large second-order and third-order nonlinear susceptibilities. We further show that the system supports a resonant interaction between longwave and shortwave and hence effective third-order nonlinear susceptibility can be further enhanced one order of magnitude. Based on these peculiar properties, we derive Davey-Stewartson equations governing the evolution of longwave and shortwave envelope, and demonstrate that it possible to generate plasmon dromions [i.e., (2 + 1)-dimensional plasmon solitons with coupled longwave and shortwave components] with very low generation power. Our study raises the possibility for obtaining new, giant Kerr effect and stable high-dimensional nonlinear plasmon polaritons at very low radiation intensity by using nonlinear PIT metamaterials.