Single-photon emission in the near infrared from diamond colour centre

TL;DR

This paper reports the discovery of Nickel-Nitrogen colour centres in natural diamond that emit narrow-band, polarized single photons in the near-infrared at room temperature, suitable for quantum communication.

Contribution

It introduces a new single-photon emitter in diamond with unique optical properties, advancing quantum communication technologies.

Findings

Emission at 780 nm concentrated in zero phonon line

Excited-state lifetime as short as 2 ns

Photoluminescence is linearly polarized

Abstract

Optically active colour centres based on Nickel-Nitrogen impurities are observed in natural diamond under continuous-wave excitation. The spectral analysis shows that the single emitters have a narrow-band emission in the near infrared, around 780 nm, which is almost entirely concentrated in the zero phonon line even at room temperature. The colour centre excited-state lifetime is as short as 2 ns, and the photoluminescence is linear polarized. These striking features pave the way to the realization of a triggered single photon source based on this colour centre emission well suited for open-air single-photon Quantum Key Distribution operating in day-light conditions.