Single-photon emission from Ni-related color centers in CVD diamond

TL;DR

This paper investigates Ni-related color centers in CVD diamond as stable, narrow-linewidth single-photon sources at room temperature, demonstrating their potential for quantum communication applications.

Contribution

It provides systematic analysis of Ni and Si ion-implanted diamond centers, revealing their narrow emission lines, high saturation count rates, and polarization properties, advancing single-photon source development.

Findings

Ni-related centers emit near-infrared photons (~770-787nm) with ~3nm linewidth.

Single-photon emission confirmed by intensity correlation measurements.

High saturation count rate of 77.9 kcounts/s observed.

Abstract

Color centers in diamond are very promising candidates among the possible realizations for practical single-photon sources because of their long-time stable emission at room temperature. The popular nitrogen-vacancy center shows single-photon emission, but within a large, phonon-broadened spectrum (~100nm), which strongly limits its applicability for quantum communication. By contrast, Ni-related centers exhibit narrow emission lines at room temperature. We present investigations on single color centers consisting of Ni and Si created by ion implantation into single crystalline IIa diamond. We use systematic variations of ion doses between 10^8/cm^2 and 10^14/cm^2 and energies between 30keV and 1.8MeV. The Ni-related centers show emission in the near infrared spectral range (~770nm to 787nm) with a small line-width (~3nm FWHM). A measurement of the intensity correlation function proves single-photon emission. Saturation measurements yield a rather high saturation count rate of 77.9 kcounts/s. Polarization dependent measurements indicate the presence of two orthogonal dipoles.