J. Matthews

J Tasker, J Frazer, G Ferranti, J C F Matthews
Silicon quantum photonics is emerging as a sophisticated platform to perform quantum information technology demonstrations and quantum optics experiments. Recent efforts have brought together on-chip generation of correlated photon pairs using four-wave mixing, with the inherent stability of nested interferometers to program electrically the manipulation quantum states to implement large scale quantum optics experiments . For example, one such recent device is a fully programmable two-qubit quantum processor that comprises more than 200 photonic components, and was used to implement 98 different two-qubit unitary operations (with an average quantum process fidelity of 93.2±4.5%), demonstrate a two-qubit quantum approximate optimization algorithm, and simulation of Szegedy directed quantum walks. A requirement of any integrated quantum optics platform is the integration into the monolithic architecture of methods to measure quantum states and characterise quantum processes. To this end, we will discuss efforts to realise homodyne detection integrated with silicon-on-insulator quantum photonics in large-scale photonic circuits. We report measured performance characteristics that are sufficient to perform quantum optics experiments. We will discuss how these performance characteristics can be improved by use of integrated electronics to perform the low noise amplification component of the detector, and we will show how this may perform beyond the state of the art with bulk optics and discrete electronics.