Ultrabright room-temperature single-photon emission from nanodiamond nitrogen-vacancy centers with sub-nanosecond excited-state lifetime

TL;DR

This paper demonstrates ultrabright, room-temperature single-photon emission from nanodiamond NV centers coupled with nanoscale plasmonic cavities, achieving sub-nanosecond lifetimes and extremely high photon rates for quantum applications.

Contribution

It introduces a novel nanostructure coupling NV centers to gap plasmonic cavities, significantly enhancing emission rates and brightness at room temperature.

Findings

Achieved sub-nanosecond NV excited-state lifetimes.

Detected photon rates up to 50 million counts per second.

Produced up to 0.25 billion photons per second in the far-field.

Abstract

Ultrafast emission rates obtained from quantum emitters coupled to plasmonic nanoantennas have recently opened fundamentally new possibilities in quantum information and sensing applications. Plasmonic nanoantennas greatly improve the brightness of quantum emitters by dramatically shortening their fluorescence lifetimes. Gap plasmonic nanocavities that support strongly confined modes are of particular interest for such applications. We demonstrate single-photon emission from nitrogen-vacancy (NV) centers in nanodiamonds coupled to nanosized gap plasmonic cavities with internal mode volumes about 10 000 times smaller than the cubic vacuum wavelength. The resulting structures features sub-nanosecond NV excited-state lifetimes and detected photon rates up to 50 million counts per second. Analysis of the fluorescence saturation allows the extraction of the multi-order excitation rate enhancement provided by the nanoantenna. Efficiency analysis shows that the NV center is producing up to 0.25 billion photons per second in the far-field.