Enhanced performance for computers or increased data security, highly sensitive measuring methods for medical engineering or environmental analyses, novel materials for improved resource efficiency: quantum-based technologies are considered key in an increasingly complex world. With 27 participating institutes at the Universities of Stuttgart and Ulm and the Max Planck Institute for Solid State Research, the Baden-Württemberg Center for Integrated Quantum Science and Technology, IQST) is an international hub and linchpin. It is staffed by top researchers from the respective Physics faculties, who work hand-in-hand with researchers from other disciplines and collaborate directly with the industrial sector to tackle future challenges based on the principles of quantum physics.
This interdisciplinary coupling of outstanding basic research with excellent applied research and partners in the industrial sector is designed to help with the transfer of a plethora of quantum-technological concepts into practical technical applications. To inspire the second quantum revolution is also the objective of the European Commission's flagship quantum research and technology initiative, which was initiated with significant input from IQST. It is one of the EU Commission's most ambitious long-term research and innovation initiatives. With a funding facility of 1 billion euro, the EU grant made available this year is designed to secure and consolidate Europe’s leading role in quantum science.
Quantum physicists work hand-in-hand with other disciplines to control individual atoms, electrons and photons with which the functions of electronic components can be modeled, which is intended to further the development of digital technology. What's more, the natural building blocks of material make ideal sensors, as they react extremely sensitively to physical stimuli and are highly precise. At the laser lab’, Professor Tilmann Pfau, Head of the Institute of Physics V at the University of Stuttgart and Director of the IQST, and his team are creating the foundations for miniaturized measuring devices. There, experimental trials are being carried out, as yet still at the macroscopic level, to find out how photons can be used to interact with and interrogate sensors.
In their search for materials with hitherto unknown properties, an interdisciplinary research team from the Max Planck Institute for Solid State Research, the University of Stuttgart and the University of Tokyo under the auspices of Professor Hidenori Takagi recently succeeded in obtaining experimental proof of an unusual quantum state of material: they were able to confirm the theoretical prediction that not all materials transition into a solid state of aggregation just above absolute freezing. What they discovered is a substance that, whilst being solid, still evinces the properties of a fluid in a magnetic sense. That is so fundamentally new that relevant application scenarios for it still need to be developed.
What happens when a lot of elementary particles such as atoms or electrons come together to form something larger such as a solid body? To what does one need to pay attention to understand its most important properties? The fact that the whole is sometimes more than the sum of its parts is something that the physicists in Professor Maria Daghofer’s team often encounter even in the model. Professor Daghofer heads up the Institute for Functional Matter and Quantum Technologies at the University of Stuttgart. One objective, among others, is to discover novel materials with exotic electronic states and, which evince phenomena such as superconductivity or high thermo-electrical levels. Superconductivity, for example, enables the generation of strong magnetic fields for use in particle accelerators, fusion reactors or MRI scanners, or else the measurement of extremely weak magnetic fields in biological systems.
In future, quantum-physical principles will play a significant role in data processing and transmission as well as in sensor technology. To this end, Professor Jörg Wrachtrup, Director of the University of Stuttgart’s Institute of Physics III, and Professor Fedor Jelezko, Director of the Institute of Quantum Optics at the Ulm University are exploiting the physical properties of diamonds: because they are so hard, they protect the atomic defects so well that quantum states can be prepared at room temperature. To manipulate ultra-pure diamonds at the atomic scale, nitrogen atoms are fired into the material, which then take the place of carbon molecules. This desirable “defect” has a magnetic component. Having been marked with a “magnetic bar code” in this way, minute diamond particles could be used to label medical agents in future, resulting in improved diagnostic systems.
Cloud computing without the security risk– that could become possible through the combination of quantum computers and quantum-technological processes for data encryption. Yet, what sounds like a practical orientation, is actually absolutely fundamental research. That’s what Professor Stefanie Barz, who heads up the “Integrated Quantum Optics” research group at the Institute for Functional Matter and Quantum Technologies is working on. The team generates individual photons and measures them with the objective of demonstrating applications from the field of quantum data, such as small quantum computers, quantum simulators and quantum networks. Bridging the gap between theoretical quantum physics and practical application requires a close collaboration with their colleagues in the engineering sciences.
Tracking quantum-mechanical process in the formation of molecules. Electrical and magnetic fields are used to trap ions, i.e., electrically charged atoms or molecules, are trapped in an ion trap. A new field of research has developed over the past few years, which involves bringing cold, trapped ions into contact with supercooled, neutral atomic gasses. Together with his colleagues in the IQST team, Professor Johannes Hecker-Denschlag, Director of the Institute of Quantum Materials at the Ulm University is studying the collisions and reactions that occur between the ions and the neutral atoms. Based on these experiments, they then draw conclusions about the interactions between the particles. The research results could contribute towards a means of forcing chemical processes to proceed in a very efficient and controlled manner.
Atmospheric vapors enclosed in glass cells are already being used as atomic clocks and magnetic field sensors. At the Institute of Physics V at the University of Stuttgart, in the context of IQST, laser stimulation is applied to combine them in highly excited “Rydberg states” in order to open up new fields of application. These range, for example, from microwave sensors to single photon sources to trace gas sensors.
Novel micro- and nanostructures often work by manipulating exquisitely sensitive quantum states. Even the most minimum contamination during the production of such structures can already impair the performance of the components. The clean rooms at the University of Stuttgart and the Max Planck Institute for Solid State Research satisfy the most stringent requirements in terms of air purity, humidity and temperature as well as EMF screening and protection from mechanical vibrations. The clean rooms’ complementary equipment encompasses a plethora of devices for the epitaxial generation of ultra-pure thin layers and volume crystals and to structure them by means of electron and ion beams as well as for the characterization of the finished components. The production of prototypes bridges the gap between the fundamental science and technological application of quantum-physical phenomena as a precursor to full industrial exploitation.
From virtual networks to the real world. The annual IQST Day is the forum at which the center presents its current research projects: it promotes the exchange of scientific knowledge and provides important stimuli for the dialogue with the economic and political spheres. Distinguished quantum researchers from around the world present their most recent results from the highly innovative field of research in which they work and explore the potential ramifications of the EU Commission’s flagship quantum science and technology initiative.
Swabian Instruments is a recent high-tech spin-off from the University of Stuttgart's Faculty of Physics. The company's products are currently developing into the most high-performing data acquisition tools in the field of physics – from quantum optics to biophysics. Their customers include outstanding scientific institutes around the world, such as MIT, Harvard University, the Universities of Cambridge and Oxford as well as private companies operating in the quantum technology sector. The demo setup depicted here was used at the 2017 IQST Day to simultaneously measure the fluorescence duration of point defects in diamonds, the optical pulse length of a pulsed laser and the reaction time of conference participants with a precision of just a few picoseconds.