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
Er3+ ions are limited by currently available host materials, motivating the development of new
Er3+-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
Er3+ introduced via implantation and via doping during growth. We demonstrate that implantation can generate a range of local environments for
Er3+, including those observed in bulk-doped materials, and that the populations of these sites can be controlled with thermal processing.
Identifying scalable materials systems that exhibit quantum behavior is a central challenge in quantum information science. Point defects in certain wide-bandgap semiconductors are promising in this regard due to the maturity of semiconductor manufacturing and ion implantation technology. Single erbium defect centers in 4H-SiC are examples of such defects that provide access to discrete defect-induced electron energy levels within the bulk material bandgap, which can be utilized for a variety of quantum technologies, such as single-photon emission for secure communication and distributed quantum computing. This work presents a first-principles study of erbium point defects in 4H-SiC using density functional theory. These results provide materials-level support for the development of Er point defects in 4H-SiC as a scalable platform for quantum devices, helping to bridge the gap between quantum physics and the practical realization of quantum networks.
The authors report systematic measurements of the lifetime of the 1.54μm transition of erbium implanted at different energies in SiO2 films coated with different metals (titanium and chromium). The lifetime shows a strong reduction (up to a factor of 20) with decreasing distance between the erbium and the metal overlay. Their experiments combined with rigorous theoretical modeling demonstrate that a high degree of control over the radiative properties of erbium can be achieved in erbium-implanted materials in a wide range of implantation energies.