Functional Renormalization Group for Interacting Many-Fermion Systems on Two-Dimensional Lattices

Abstract

Functional renormalization group (fRG) methods have become a widely used tool to investigate the low-energy properties of interacting fermions. In particular for two-dimensional lattice systems with competing ordering tendencies, they are very suitable for investigating the interplay of various possible instabilities and their mechanisms. Here we review the main elements of the fRG method, its current state and some applications to correlated electron systems where the fRG has proved useful, and outline some issues for the further development of the method.