Department of Physics

Research interests

In Theoretical Physics the question for the fundamental constituents of nature (i.e. elementary particles, symmetries and interactions) has an obvious appeal to our natural curiosity. This question is typically studied within the field of Particle Physics. From the antipodal perspective, an equally exciting question is the one for the physical states that matter can acquire given a large number of fundamental constituents, which is the subject of Condensed Matter Physics. Both fields are strongly intertwined, for example, the collective behavior in solids can give rise to particle excitations which behave like relativistic Dirac fermions as known from Particle Physics.

The research of our group is focused on the exploration of various aspects of interactions and phase transitions in Condensed Matter Physics, Quantum Field Theories and Particle Physics.

More specifically, we study the collective behavior of complex quantum systems consisting of many interacting particles (for example electrons in graphene and related materials). Starting from a collection of basic ingredients, as the nature of the considered particles (bosons, fermions), interactions (local, long-ranged, spin-orbit coupled,...) and symmetries (crystal lattice structure,...), we explore universal as well as non-universal properties of (quantum) phases and phase transitions towards magnetically ordered, superconducting and more exotic states of matter. Moreover, we also study aspects of the electroweak phase transition and the Higgs mass in the Standard Model of Particle Physics.

We employ modern quantum field theoretical methods, e.g., perturbative and functional renormalisation group approaches. Research topics include:

Correlated quantum-many body systems

  • Dirac and Weyl materials
  • Quantum critical phenomena
  • Competing order parameters
  • Quantum phase transitions beyond the Landau-Ginzburg paradigm
  • Emergent symmetries
  • Strongly-correlated electrons
  • High-temperature superconductors
  • Spin-orbit coupled materials
  • Ultracold quantum gases.

  • Renormalisation group methods

  • Functional Renormalisation Group
  • Non-perturbative expansion schemes
  • Loop calculations, epsilon expansion
  • Relations to other quantum many-body methods

  • High-Energy Physics

  • Higgs mass and the scale of new physics
  • Ultraviolet completions for the standard model

  • My research articles can be found on the arXiv or on Google Scholar.