The overall competence of this research department lies in the physics and applications of semiconductor hetero- and nanostructures, in particular with regard to their electronic and optical properties. The research topics include the investigation of elementary excitations in solids controlled by surface acoustic waves, the optical properties of III-V nanowires and heterostructures, terahertz quantum-cascade lasers, spin generation and transport in ferromagnet-semiconductor hybrid structures, quantum transport in semiconductor-based nanoscale systems, and topological insulators. Dedicated spectroscopic and magneto-transport techniques are used to determine the electronic, optical, and transport characteristics of these semiconductor hetero- and nanostructures.