  We present a practical new method for fabricating a coupled single quantum
emitter-plasmonic nanoantenna system. Emission characteristics of a single
defect center embedded in hexagonal Boron Nitride (hBN) multilayers is modified
using plasmonic nanoantennas. By dewetting thin silver films on hBN
multilayers, plasmonic nanoantennas are obtained in a size controlled way with
no adverse effects on the defects. A very same single defect center is
investigated with and without nanoantenna in order to demonstrate the
modification of its emission characteristics. Based on the initial silver film
thickness in dewetting process, on-demand enhancement and quenching effects are
observed. For attaining deterministic coupling strengths, an electromagnetic
simulation model is employed in the light of experiments. Fluorescence
lifetime, radiative and nonradiative emission rate calculations are used for
estimating the spatial configuration of the defect-nanoantenna system as well
as for confirming the experimental findings. Our approach provides a low-cost
and uncomplicated coupling scheme as an alternative to the scanning probe tip
antenna technique.
