The high degree of perfection achievable in nowadays semiconductor nanostructures is key to the progress in solid-state-based quantum technology. The group, supported by Thomas Ihn (titular professor), has pioneered methods for the fabrication of such structures on a nanometer scale. In addition, sophisticated magnetotransport studies are carried out at dilution refrigerator temperatures to explore (single-) charge and spin transport as well as carrier-carrier and spin-orbit interaction effects. Fractional quantum Hall effect phases represent another intensively investigated topic, not only because of the intriguing physics but also due their applications in topological quantum computing. Systems under current investigation range from well-established GaAs based semiconductors over novel materials, like graphene, to superconductor-semiconductor hybrid structures.