  Deterministic GHz-rate single photon sources at room-temperature would be
essential components for various quantum applications. However, both the slow
intrinsic decay rate and the omnidirectional emission of typical quantum
emitters are two obstacles towards achieving such a goal which are hard to
overcome simultaneously. Here we solve this challenge by a hybrid approach,
using a complex monolithic photonic resonator constructed of a gold nanocone
responsible for the rate enhancement, and a circular Bragg antenna for emission
directionality. A repeatable process accurately binds quantum dots to the tip
of the antenna-embedded nanocone. As a result we achieve simultaneous 20-fold
emission rate enhancement and record-high directionality leading to an increase
in the observed brightness by a factor as large as 580 (120) into an NA = 0.22
(0.5). We project that such miniaturized on-chip devices can reach photon rates
approaching 2.3*10^8 single photons/second thus enabling ultra-fast
light-matter interfaces for quantum technologies at ambient conditions.
