Fundamental properties of matter change drastically at the nanometer scale in the quantum regime. The impact of dimensionality affects essentially all interactions associated with electronic, vibrational, and optical excitations. In semiconductors, a material class broadly relevant for basic research and modern technology, it leads to emergence of electronic many-particle states determining charge, energy, and information transport as well as the response to light. The resulting collective phenomena offer rich playground for basic physics of interacting systems and intriguing pathways to design properties of matter.

Our research is focused on studying interactions of electronic many-particle states in low-dimensional semiconductors using a variety of optical techniques from linear and non-linear spectroscopy to time-resolved microscopy. We address an expanded material base of artificially assembled nanostructures to develop fundamental understanding and advanced concepts for manipulation and control of light-emitting excitations. Our aim is to address technologically motivated, critical questions from basic science perspective.