Abstract
Erbium implanted silicon is promising for both photonic and quantum technology platforms, since it possesses both telecommunications and integrated circuit processing compatibility. However, several different Er centres are generated during the implantation and annealing process, the presence of which could hinder the development of these applications. When Si is co-implanted with 1017 cm-3 Er and 1020 cm-3 O ions, and the appropriate annealing process is used, one of these centres, which is present at higher Er concentrations, can be eliminated. Characterisation of samples with Er concentrations <1017 cm-3 Er is limited by the sensitivity of standard electron paramagnetic resonance (EPR) instruments. The collective coupling strength between a superconducting (SC) NbN lumpedelement resonator and a 1017 cm-3 Er implanted Si sample at 20 mK was measured to be ~ 1 MHz, which provides a basis for the characterisation of low concentration Er implanted Si and for future networks of hybrid quantum systems that exchange quantum information over the telecommunication network. Out of six known Er-related EPR centres, only one trigonal centre coupled to the SC resonator