Generation of Bessel plasmon-polaritons on the boundary of epsilon-near-zero metamaterials

The conditions are found for the existence of Bessel plasmon-polaritons (BPPs) at the boundary of an epsilon-near-zero (ENZ) metamaterial formed from array of metal nanocylinders embedded into dielectric matrix. It is shown that BPP is a new type of surface plasmonic field, namely, cylindrically symmetric interference structure with phase singularity in its center and amplitude exponentially decaying into metamaterial and radiative into free space. The dependence is established of the size of central dark spot of such vortex BPP on its topological charge.