Scalability of systems for quantum hardware is of paramount importance for the creation of realistic quantum computers. Several exciting platforms have been identified for the creation of quantum hardware, spanning from superconducting circuits and ultracold atoms, to solid state defect centres and semiconductor quantum dots. Despite the fact that semiconductor quantum dots show great potential on an individual quantum emitter level, the inhomogeneous broadening within groups of emitters, hinders direct applications towards scalable systems. This project focuses on the investigation of a novel hybrid approach to overcome this issue, whereby we will utilize the delocalised nature of light-matter quasiparticles called microcavity exciton-polaritons, to mediate interactions between individual quantum dots that are spatially and spectrally separated.

This scheme promises fast single-shot quantum non-demolition measurement of individual spin qubits, universal spin qubit operation and the creation of two-qubit phase gates. The project’s main objectives are the design and characterisation of the hybrid exciton polariton-quantum dot platform, the evaluation of the impact of the hybrid character on the coherence properties of the quantum dot qubits, the demonstration of universal single-qubit quantum gate operation and the realisation of two-qubit quantum gates, via the microcavity polariton information bus.