IQIT will develop and demonstrate novel routes towards scaling up physical devices for quantum in-formation science (QIS). Communication between different parts of a quantum processor by means of a quantum bus will receive particular attention. Developing a scalable technology will be pursued by first advancing two successful solid-state and atom-optical devices, namely A) arrays of superconducting qubits coupled to microwave resonators – here all-optical quantum computing will be explored for the first time in the microwave regime – and B) highly controlled ion trap systems. Then, decisive steps will be undertaken to combine these systems to form a scalable basis for processing of quantum information. This new, integrated scheme will be based on the simultaneous exploitation of superconducting qubits for fast and scalable computational tasks and of trapped ions for storage and processing of information with long coherence times. On the side of superconducting qubits, a highly innovative route towards all-"optical" quantum computing will be explored. Here, the photons serving for transport of quantum information are in the microwave regime. On the ion trap side novel traps will be developed suitable for integration and new techniques will be derived to further increase the lifetime of trapped-ion qubits, thus making an essential contribution to the storage of quantum information. In addition, novel schemes for the creation of arbitrary entangled states within a trapped-ion register will be developed by taking advantage of long-range spin-spin coupling. This will enable fast and efficient information transfer between both types of quantum registers (solid state qubits and trapped ion qubits), which in turn, will be of central importance for the integration of the superconducting and the trapped-ion processor units.Experiment and theory will closely collaborate at all stages of this project, and importantly, a close collaboration between hitherto mostly separately developing subfields of quantum information science (solid state and atomic-molecular-optical physics) will be established allowing to combine and exchange the tremendous knowledge and expertise in both fields. The project's long-term vision is an integrated scalable device for QIS. The breakthroughs envisioned are, 1st the design, realization, and test of an integrated processor with superconducting gates and trapped ions register, and, based on the knowledge gained here, 2nd the design of a scalable integrated architecture.