Cavity-coupled spin qubits for networked quantum information technologies

Colour centres in wide gap materials are leading contenders for the realisation of large-scale quantum computers, offering the possibility of qubit densities ~106 cm-2 or more on a chip, coupled via an optical network. Efficient coupling between the spin nodes and the network will be essential to enable the fidelity of entanglement between nodes to surpass the fault tolerance threshold. This project concerns the coupling of colour centres in diamond and silicon carbide to monolithic microcavities as a means to enhance the spin/photon coupling efficiency.

The project will employ a variety of fabrication tools including laser processing, focused ion beam milling, plasma etching and thermal treatments to produce arrays of monolithic cavity devices with coupled colour centres. Devices will be fabricated and characterised for spin and optical coherence, the key figures of merit for building large scale quantum networks.

The project contributes to a wider team effort in the realisation of quantum memory chips within the new UK Hub for Integrated Quantum Networks (IQN), and involves collaboration with several research groups in the UK and internationally.