Brightness Enhancement of Room-Temperature Telecom Single-Photon Emitters in GaN

In the prospect of a global quantum information network, defect-based single-photon sources in gallium nitride, operating in the telecom wavelength range, at room temperature, and with spin-addressable states, appear to be some of the most promising candidates for the interfacing between distant quantum nodes. In this article, we focus on the optimization of these single-photon sources for practical applications by embedding them into bullseye cavities. In particular, we separately measure an enhanced detected count rate as well as an acceleration of the recombination rate by a factor of 2 and discuss how the Purcell effect could explain such enhancement. In the process of studying the evolution of the emitters' properties before and after their embedment into photonic structures, we also disclose two major challenges of these sources, namely, their spectral and photostability. Our results pave the way for large-scale usage of GaN-based telecom single-photon sources for quantum communications.