SnV Centers in Nanophotonic Diamond Cavities for Quantum Networks, Part I: Generation and Integration

Quantum networks will require entanglement distribution to processing qubits on its end nodes via optical channels. Optically active spin qubits, such as tin-vacancy (SnV) centers in diamond, have emerged as one of the leading candidates to implement quantum networking hardware due to their favorable optical and spin properties. Their first order insensitivity to charge noise renders SnVs excellent for integration into nanophotonic devices. The extended spin coherence and controllability of the qubit at temperatures around 1K offer significant potential for high-efficiency photon collection and spin-photon entanglement generation beyond current state of the art. However, reliable activation of colour centers upon high temperature annealing is a major challenge due to graphitization. Here we show our method of systematic activation of SnV centers in bulk diamond and show optical stability of activated colour centers. In addition, we present latest results on our optimized quasi-isotropic crystal plane dependent reactive-ion-etch fabrication process flow to fabricate nanophotonic diamond devices.