# Analogue of double-$\Lambda$-type atomic medium and vector dromions in a plasmonic metamaterial

## TL;DR

This paper demonstrates that a specially designed plasmonic metamaterial can mimic atomic systems with complex interactions, exhibit nonlinear effects like plasmon induced transparency, and support stable high-dimensional vector plasmonic dromions with low power requirements.

## Contribution

It introduces a classical analogue of a double-Λ atomic medium in a plasmonic metamaterial and shows the emergence of vector dromions with low power and robustness.

## Key findings

- Metamaterial exhibits plasmon induced transparency similar to atomic systems.
- System supports high-dimensional vector plasmonic dromions with low power.
- Giant second- and third-order Kerr nonlinearities are achieved.

## Abstract

We consider an array of the meta-atom consisting of two cut-wires and a split-ring resonator interacting with an electromagnetic field with two polarization components. We prove that such metamaterial system can be taken as a classical analogue of an atomic medium with a double- $\Lambda$-type four-level configuration coupled with four laser fields, exhibits an effect of plasmon induced transparency (PIT), and displays a similar behavior of atomic four-wave mixing (FWM). We demonstrate that when nonlinear varactors are mounted onto the gaps of the split-ring resonators the system can acquire giant second- and third-order Kerr nonlinearities via the PIT and a longwave-shortwave interaction. We also demonstrate that the system supports high-dimensional vector plasmonic dromions [i.e. (2+1)-dimensional plasmonic solitons with two polarization components, each of which has a coupling between a longwave and a shortwave], which have very low generation power and are robust during propagation. Our work gives not only a plasmonic analogue of the FWM in coherent atomic systems but also provides the possibility for obtaining new type of nonlinear polaritons in plasmonic metamaterials.