Quantum physics forms the fundamental basis of solid state physics and chemistry, modern optics, and quantum information science. Important research areas in this field are semiconductor physics with applications in microelectronics, the physics of superconductors, quantum optics with applications in laser physics, the field of highly correlated matter and quantum materials, and quantum information technologies. While conventional computer science is based on the laws of classical physics, the currently emerging quantum information theory invokes the quantum mechanical nature of microscopic objects in order to explore new possibilities in information processing. Often we are asking about the effects of quantum laws on classically known behavior, e.g. in electrical conductivity or electrical or optical fluctuations. But sometimes we also find quantum phenomena that have no classical analogue and that can lead to completely new applications. In Konstanz, we investigate quantum phenomena in electrical circuits, materials and devices, the fundamental quantum fluctuations of the electromagnetic field, as well as solid-state systems for quantum information processing. Maybe even free electrons in an electron microscope can be used for quantum information processing?