  We report single plasmon generation with a self-assembled InAs/GaAs quantum
dot embedded in a plasmonic microring resonator. The plasmonic cavity based on
a GaAs microring is defined on an atomically-smooth silver surface. We
fabricated this structure with the help of transfer printing, which enables the
pick-and-place assembly of the complicated, heterogeneous three dimensional
stack. We show that a high-order surface-plasmon-polariton transverse mode
mediates efficient coupling between the InAs/GaAs quantum dots and the
plasmonic cavity, paving the way for developing plasmonic quantum light sources
based on the state-of-the-art solid-state quantum emitters. Experimentally, we
observed Purcell-enhanced radiation from the quantum dot coupled to the
plasmonic mode. We also observed a strong anti-bunching in the intensity
correlation histogram measured for scattered photons from the plasmonic
resonator, indicating single plasmon generation in the resonator. Our results
will be important in the development of quantum plasmonic circuits integrating
high-performance single plasmon generators.
