I am a theorist in condensed matter physics with a strong interest on peculiar properties of novel quantum materials. First, I have been fascinated by carbon nanotubes that can be understood as quasi-1D system where Fermi liquid theory breaks down and strong electronic correlations need to be taken into account. Subsequently, as a postdoc in Leiden and Basel, I have been working on the physics properties of graphene. This 2D material is exciting by many means, for instance, its low-energy excitations are not described by the Schrödinger equation (as it is usually the case in condensed matter physics) but by the Dirac equation. Recently, I have mainly worked on the underlying physics and mathematics of topological materials, like topological insulators, topological superconductors, and Weyl semimetals. This rich area of research connects nicely the abstract concepts of topology in mathematics to real world materials. Furthermore, the interplay of spin-orbit coupling, Coulomb interaction, superconductivity, and magnetism leads to a plethora of fascinating phenomena in this material class. In 2007, I was appointed as associate professor in physics at Würzburg University and in2011 I was promoted to the full professor level. Together with my colleague Ralph Claessen, we form the spokespersons of the SFB 1170 on “Topological and Correlated Electronics at Surfaces and Interfaces”.
Today the focus of my research is on:

• Transport and spectral properties of topological insulators and topological superconductors
• Unconventional superconductivity and Majorana fermions (relation to odd-frequency superconductivity)
• Many-body localization in central spin models
• Interplay of Coulomb interaction and spin-orbit coupling in interacting topological materials