Low temperature optical characterization of near infrared single photon emitters in nanodiamonds

TL;DR

This study investigates the optical properties of near-infrared single photon emitters in nanodiamonds at cryogenic temperatures, revealing their potential for quantum computing applications due to their stable, polarized, and narrow-linewidth emission.

Contribution

It provides detailed optical characterization of near-infrared single photon emitters in nanodiamonds, highlighting their spectral stability and suitability for quantum interference experiments.

Findings

Sharp zero-phonon line emission in the near infrared

Radiative lifetime in the nanosecond range

Optical resonance linewidth of 4 GHz

Abstract

In this paper, we study the optical properties of single defects emitting in the near infrared in nanodiamonds at liquid helium temperature. The nanodiamonds are synthesized using a microwave chemical vapor deposition method followed by nickel implantation and annealing. We show that single defects exhibit several striking features at cryogenic temperature: the photoluminescence is strongly concentrated into a sharp zero-phonon line in the near infrared, the radiative lifetime is in the nanosecond range and the emission is perfectly linearly polarized. The spectral stability of the defects is then investigated. An optical resonance linewidth of 4 GHz is measured using resonant excitation on the zero-phonon line. Although Fourier-transform limited emission is not achieved, our results show that it might be possible to use consecutive photons emitted in the near infrared by single defects in diamond nanocrystals to perform two photon interference experiments, which are at the heart of linear quantum computing protocols.