Polarisation singularities on plasmonic nanowires
Summary
Placing quantum dots at polarisation singularities is expected to allow for
direct control over the directionality of the emitted light. Possibly creating
a photon driven quantum bit. Here, we investigate the occurrence of polar-
isation singularities on plasmonic nanowires with periodic extrusions. We
build a 3D model based on a finite element method in order to calculate the
electric fields using Floquet periodicity and the theory of surface plasmons,
propagating along the metal-dielectric interface.
To validate our model we first show qualitative agreement between results ob-
tained with the 3D model and earlier 2D models of a straight wire. Secondly
we develop a piece of mathematics that allows for determining polarisation
singularities independent of a reference frame and we show that polarisa-
tion singularities exist on plasmonic nanowire with periodic extrusions at
the surface of the metal.