Quantum. Network. Perspectives - Research group leaders from the Quantum Information National Laboratory of Hungary and cutting-edge professors of quantum technology research from Stuttgart, Ulm, Tübingen, Karlsruhe and Konstanz presented the results of their research groups and future research directions at a joint workshop on 3 June 2022 at the world-class research building, the Centre for Applied Quantum Technology (ZaQuant), which was opened last year at the University of Stuttgart. In addition to the research group leaders, the workshop was attended by researchers from the University of Stuttgart's Centre for Applied Quantum Technologies and the Institute for Functional Materials and Quantum Technologies, and was joined online by researchers from Japan, Korea, China and India. The program of the workshop was put together by Professor Adam Gali, research group leader at the Wigner Research Centre for Physics, who is also responsible for the development of international collaborations at the Quantum Information National Laboratory of Hungary, and Professor Jörg Wrachtrup, Head of the Centre for Applied Quantum Technologies in Stuttgart. The research group leaders see promise for further networking with the region, which is highly active in the field of quantum technologies, with a view to future joint development projects and joint participation in consortium proposals. Quantum technology research is also a perspective area for future bilateral "positive agendas" in the German-Hungarian relationship.
The workshop was opened by Professor Jörg Wrachtrup, two-time winner of a prestigious European Research Council (ERC) Advanced Grant, Head of the Research Center opened last autumn, who explained how their Integrated Quantum Science and Technology Centre (IQST) initiative has become an internationally competitive centre for quantum science and technology, the flagship programme of the German Quantum Alliance cluster of excellence. Launched in collaboration between Ulm University, the University of Stuttgart and the Max Planck Institute for Solid State Research (Stuttgart), the programme relied on interdisciplinary solutions from materials scientists, chemists, computer scientists and engineers to explore the full potential of quantum simulators, quantum computing, quantum communication, quantum sensing and quantum algorithms. As one of the highlights of the workshop, Professor Wrachtrup hosted a guided tour of the precision building designed to meet the needs of the best quantum technology researchers in Stuttgart, the physics, chemistry, biochemistry and laser laboratories, and the world-class, purpose-built measurement facilities at the heart of the facility. These ten-metre-high 'laboratory cubes' in the basement are supported on concrete foundations weighing over 150 tonnes, resting on pneumatically controlled air springs with millimetre precision, to ensure complete vibration isolation. To achieve a completely unobstructed measurement space, the individual building sections were built like an onion skin around the measurement rooms and separated by construction joints. The €41.5 million research building currently houses 15 working groups, from which the land expects significant results in the testing and development of new manufacturing processes for quantum sensors. Experts in quantum physics and photonics will work with engineers to develop prototypes of quantum technologies that can be transferred to industry. The consortium leader of the Quantum Information National Laboratory of Hungary, Professor Péter Domokos, PI at the Wigner Centre for Physics, presented the three strategic objectives of the national laboratory, the creation of a regional quantum communication network to be connected to the "quantum internet" planned in the European Union, and the development of hardware components based on photons, atoms and artificial atoms for quantum computing operations in a competitive infrastructure, as well as the building of Hungarian expertise in quantum computing with cutting-edge knowledge in quantum computing, able to use quantum computers as users in large infrastructures. The consortium leader presented the programmes that underpin the quantum research competences of the institutions and research groups that make up the national laboratory, their international links and their industrial collaborators. Guido Burkard, Professor at the Department of Physics, University of Konstanz, gave an overview of the research focus areas of the Condensed Matter Theory and Quantum Information research group, with a special emphasis on their achievements in the theoretical approach to spin-photon interfaces and quantum memories. In his presentation, the professor appreciated previous publications in collaboration with Hungarian researchers. Péter Makk, a researcher from the Quantum Electronics Research Group of the BME Budapest University of Technology and Economics, presented their research results on the development of memory devices based on new principles for building quantum computers, quantum bits, based on the development of nanoelectronic circuits combining superconducting materials with various two-dimensional materials. Alexey Ustinov, Professor at the Karlsruhe Institute of Technology, who received an ERC Advanced Grant this year for his ambitious project to develop a new generation of superconducting quantum bits, presented their new research approach to increase the operating frequency of qubits from today's average of ten to one hundred gigahertz to take quantum computing to new levels. Péter Rakyta, a PI from the Institute of Physics at Eötvös Science University presented a project related to a photonic quantum computer simulator for programming and simulation of optical quantum computers, developed in the framework of the Quantum Information National Laboratory of Hungary for the support of international cooperation in quantum research. Fedor Jelezko, Director and Research Professor of the Institute of Quantum Optics at the University of Ulm, presented his research results related to a room-temperature diamond-based quantum simulator, which is part of the "Quantum Technologies" research programme funded by the Baden-Württemberg Foundation with a total of €5 million over three years from 2021. Funding under the Quantum Technologies Baden-Württemberg (QTBW) Competence Network aims to help the best quantum technology researchers to transfer their results into practical applications as soon as possible. The programme focuses on networking to strategically position the region as a leading research hotspot. One of the key tasks of the QTBW.net competence network will be to establish an international programme of fellows and scientists, provide research opportunities for PhD students and post-docs, and engage industrial partners. Gergely Zaránd, Director of the Institute of Physics and Professor of the Department of Theoretical Physics at the Budapest University of Technology and Economics, presented research results that could contribute to the development of quantum data storage devices, which are essential for quantum communication applications. Professor József Fortágh gave an overview of the research results based on the system of captured atoms at the University of Tübingen, including collaborating partners in Hungary. Zoltán Zimborás, researcher at the Wigner Research Centre for Physics, gave an insight into the results of a noise reduction method for quantum circuits, which could contribute to a more efficient use of resources in quantum processors, using by an algorithm developed with colleagues. Professor Sebastian Loth, Head of the Institute for Functional Materials and Quantum Technologies at the University of Stuttgart and one of the coordinators of the QTBW, gave an overview of the institutions and the workings of the quantum network, in addition to presenting the results of the research group. He underlined that in Germany, according to the Quantum Systems 2030 Roadmap, priority federal and state support is given to basic and problem-oriented research related to the implementation of quantum technologies. For example, immediately after the opening of the ZAQuant Research Centre, two new large-scale facilities at the University of Stuttgart were supported last year with EUR 2.5 million from the REACT-EU framework for additional recovery funding for coronavirus response: a microscope designed for research on qubit networks and a segregation cryostat used to better understand the microwave properties of superconducting materials.