Overcoming the Rate-Directionality Trade-off: A Room-Temperature Ultrabright Quantum Light Source

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 toward 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, enclosed by 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 800 (130) into an NA = 0.22(0.5). We project that these miniaturized on-chip devices can reach photon rates approaching 1.4 x 10(8) photons/s and pure single photon rates of >10(7) photons/second after temporal purification processes, thus enabling ultrafast light-matter interfaces for quantum technologies at ambient conditions.

Automated summary

Deterministic GHz-rate single photon sources at room temperature were achieved by using a complex monolithic photonic resonator and a circular Bragg antenna, which resulted in a 20-fold emission rate enhancement and record-high directionality, showing great potential for ultrafast light-matter interfaces for quantum technologies.