Colour centres in diamond are a leading platform for the realisation of universal quantum computers, offering the possibility of qubit densities ~106 cm-2 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 fabrication of monolithic diamond microcavities to achieve these high efficiencies, and their coupling to NV centres.
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 NV centres. Devices will be fabricated and characterised for spin and optical coherence, targeting demonstrations of quantum interference between photons as a precursor to entanglement between NV centres.
The project contributes to a wider team effort in the realisation of diamond quantum computer chips within the new UK Hub for Quantum Computing and Simulation, and involves collaboration with several other groups in the UK and internationally.