Ronny Thomale (Princeton). Please note the unusual time and location!
Phase transitions are often complicated to be treated in a diagrammatic expansion of 2-particle Greens functions. This is because given that two neighboring phases reside in different channels of parquet diagrams, all vertex corrections have to be taken into account to obtain a good description of the phase transition regime. We report on our functional renormalization group (FRG) approach for multi-band Fermi instabilities which we use to investigate competing phases in the iron-based superconductors. In addition, we discuss recent progress in collaboration with Johannes Reuther and Peter Wölfle on developing a slave particle (pseudofermion) FRG scheme to analyze frustrated magnetic systems in two dimensions. We present our results for the anisotropic triangular antiferromagnet, the J1-J2-J3 honeycomb model, and recent investigations for the Heisenberg-Kitaev Model of certain Iridate compounds.
A 010 Theresienstr. 37