Abstract
In this thesis we investigate the potential of erbium ions coupled to crystalline whispering-gallery mode resonators as hardware for quantum information processing. Achieving strong coupling between the erbium ions and the cavity would be a significant breakthrough for multiple quantum computing applications. To this end, we fabricate millimetre-sized resonators made from 0.001% erbium-doped yttrium orthosilicate (Er 3+ :Y 2 SiO 5 ). We show that the mechanical fabrication procedure used in making the resonators does not significantly impact the coherence properties of the erbium dopants.
We find that strong coupling should be achievable using currently available technologies, so long as significant absorption in the Y 2 SiO 5 crystals is not present at the wavelength of the erbium transition.