CMT Group Seminar | January 21, 10:00

Functional renormalization group approach to phases of broken symmetries and multiband models

Stefan Meier

Functional renormalization group (fRG) methods relate theories at different energy scales via an exact flow equation for a functional of the fields. In this talk, I will focus on a one-particle irreducible, purely fermionic formulation and, in particular, on its application to phases of broken symmetries and multiband Hubbard models. First, I will report on a recent fRG study on antiferromagnetic ordering in a simple two-pocket model, including a possible extension to coexistence phases of antiferromagnetism and superconductivity. The second part will be devoted to multiband systems. Particularities of the point-group behavior of multiband Hubbard models are discussed and fRG results are presented for a generic three-band model for the cuprate superconductors. Finally, an outlook on a potentially highly parallelizable fRG algorithm is given, which should be suitable for calculations with a larger number of bands.



Seminar room 03, ETP
Contact: not specified