Accessing the silicon vacancy centers electron spin in nanodiamonds with hybrid quantum photonics

Efficient connection of stationary- and flying qubits posts a formidable challenge yet is one of the demands for the development of applications like quantum networks, distributed quantum computing and quantum communication. Cavity quantum electrodynamics (cQED) typically serves as the tool to enhance light-matter interaction in order to realize spin-photon interfaces. Chip-integrated cavities have gained attention in recent years [1, 2], as they are accompanied with a small footprint which is benefitting scalability. Our efforts to realize such an efficient light-matter interface is based on a hybrid approach. Here, we utilize the electron spin degree of freedom of negatively charged silicon vacancy centers (SiV) as the spin system, hosted in a nanodiamond, which can provide prolonged orbital coherence [3]. The photon interface part is taken over by on one-dimensional photonic crystal cavities in silicon nitride (Si3N4). This hybrid interconnection allows for separate optimization of the photonic design as well as preselection of the nanodiamond host. Here, we present our progress of this interconnection and the achieved cQED parameters, which has provided Purcell broadened optical access to the SiV centers electron spin [4] while preserving the spin-properties of the SiV, even after integration.