Lead-Related Quantum Emitters in Diamond

TL;DR

This paper reports on the discovery and characterization of lead-related quantum emitters in diamond, highlighting their potential for quantum networking due to their optical and spin properties.

Contribution

It introduces Pb-related color centers in diamond as new quantum emitters, supported by experimental observations and first-principles calculations.

Findings

Observation of Pb-related emission lines at 520 nm

Identification of a large doublet splitting of 2 THz

Confirmation of the PbV center as a promising quantum system

Abstract

We report on quantum emission from Pb-related color centers in diamond following ion implantation and high temperature vacuum annealing. First-principles calculations predict a negatively-charged Pb-vacancy center in a split-vacancy configuration, with a zero-phonon transition around 2.3 eV. Cryogenic photoluminescence measurements performed on emitters in nanofabricated pillars reveal several transitions, including a prominent doublet near 520 nm. The splitting of this doublet, 2 THz, exceeds that reported for other group-IV centers. These observations are consistent with the PbV center, which is expected to have the combination of narrow optical transitions and stable spin states, making it a promising system for quantum network nodes.