Quantum Dot coupling engineering (and dynamic spin decoupling/deep nuclei cooling): 2-dimensional cluster state generation for quantum information processing

The overarching objective of QCEED is to find solutions to current bottlenecks to photonic quantum information processing. “Scalable” photonic universal quantum computation exploits the measurement-based quantum computing paradigm relying on multi-dimensional photonic cluster states.However, the technological capability to generate on-demand, large-scale 2-dimensional cluster states has not yet been proven.QCEED will demonstrate the (large-scale, i.e., many photons) emission of 2-dimensional cluster states of light thanks to the development of new engineered paired semiconductor quantum dot (QD) systems, and the exploitation of advanced deep nuclei cooling and/or dynamic spin decoupling to improve system coherence time.To achieve this, one needs to deterministically design QD coupling/pairing and ultimately tailor specific molecular states/architectures (lambda like energy levels). Conventionally exploited self-assembled QD systems (e.g., SK or droplet epitaxy QD systems) are in general not suited for the task. QCEED will attack the issue with a twin-track approach and demonstrate the advantage of MOVPE site-controlled (In)GaAs pyramidal QDs and CBE InAsP nanowire QDs. QCEED will also tackle the essential requirement for scalable quantum computation -that is to efficiently funnel the generated photons into specific photonic modes- by implementing tailored tapered wave-guiding designs and broadband optical cavities with relatively high Purcell factors. QCEED brings together 7 partners from 5 countries which combined possess all the complementary expertise necessary to fulfil the ambitious objectives and to prepare a post-project sustainability and exploitability plan.The combined effort will result in a new scalable platform of semiconductor sources of multidimensional cluster states for efficient quantum information processing. If successful, large scale, on chip, quantum photonic computation will be a significantly closer certainty