Functional devices for quantum information processing and communication must make use of appropriate matter-light interfaces. Their key role in bringing quantum devices towards practical applications is essential. Hence, building the conceptual and technological base for such interfaces will pave the way for the scalable quantum computation and quantum Internet. The overall objective of this proposal is to meet the critical challenge of studying, implementing and optimizing ground-breaking, dynamically-controlled interfaces between matter and light.

Photons can efficiently and durably transmit quantum information over large distances; cold, trapped ions can be manipulated to enable high-fidelity quantum information processing, while atomic ensembles are particularly suited for long-lived quantum memories, as well as nonlinear generation of non-classical correlations between optical beams. The aim of PACE-IN project is the development of reliable quantum interfaces between atomic systems and photons. We shall develop and demonstrate massive parallel processing, storage and transmission of quantum information by hitherto unexploited collective, multimode quantum states or atomic ensembles and ionic crystals, and design methods to characterize the entanglement and non-classicality of quantum states transferred from atoms and ions to photons.

Efficient interfacing mechanisms between “stationary” atomic qubits or ensembles and “flying” (photonic) quantum variables, whether discrete or continuous, must be robust and dynamically controllable to allow the best possible exploitation of their respective functionalities while maintaining the highest possible overall fidelity/coherence and speed. The scientific and technological challenge that will be addressed in this project is the conceptually and experimentally optimized quantum information processing and manipulation at interfaces for the successful implementation of scalable quantum technologies in combination with long distance quantum communication.