Microscopic derivation of effective model Hamiltonians

The project aims to provide an improved construction of effective low-energy models for Rydberg systems with long-range interactions. Their precise determination is crucial for a quantitative theory. The functional renormalization group based scheme that is going to be developed, allows to account for the renormalization of the bare interaction due to virtual transitions of particles from the low-energy target bands to higher energy ones. This is expected to lead to effective multi-body interactions which can have an important impact on emergent collective behavior and the associated low-energy phase diagram.