Erbium-implanted materials for quantum communication applications

Abstract

Erbium-doped materials can serve as spin-photon interfaces with optical transitions in the telecom $C$ band, making them an exciting class of materials for long-distance quantum communication. However, the spin and optical coherence times of ${\mathrm{Er}}^{3+}$ ions are limited by currently available host materials, motivating the development of new ${\mathrm{Er}}^{3+}$-containing materials. Here we demonstrate the use of ion implantation to efficiently screen prospective host candidates, and show that disorder introduced by ion implantation can be mitigated through post-implantation thermal processing to achieve inhomogeneous linewidths comparable to bulk linewidths in as-grown samples. We present optical spectroscopy data for each host material, which allows us to determine the level structure of each site, allowing us to compare the environments of ${\mathrm{Er}}^{3+}$ introduced via implantation and via doping during growth. We demonstrate that implantation can generate a range of local environments for ${\mathrm{Er}}^{3+}$, including those observed in bulk-doped materials, and that the populations of these sites can be controlled with thermal processing.