  Plasmonic antennas are attractive optical structures for many applications in
nano and quantum technologies. By providing enhanced interaction between a
nanoemitter and light, they efficiently accelerate and direct spontaneous
emission. One challenge, however, is the precise nanoscale positioning of the
emitter in the structure. Here we present a laser etching protocol that
deterministically positions a single colloidal CdSe/CdS core/shell quantum dot
emitter inside a subwavelength plasmonic patch antenna with three-dimensional
nanoscale control. By exploiting the properties of metal-insulator-metal
structures at the nanoscale, the fabricated single emitter antenna exhibits an
extremely high Purcell factor (>72) and brightness enhancement by a factor of
70. Due to the unprecedented quenching of Auger processes and the strong
acceleration of multiexciton emission, more than 4 photons per pulse can be
emitted by a single quantum dot. Our technology permits the fabrication of
bright room-temperature single-emitter sources emitting either multiple or
single photons.
