Kagome Hubbard model from a functional renormalization group perspective

Abstract

The recent discovery of a variety of intricate electronic order in kagome metals has sprouted significant theoretical and experimental interest. From an electronic perspective on the potential microscopic origin of these phases, the most basic model is given by a Hubbard model on the kagome lattice. We employ a functional renormalization group (FRG) to analyze the kagome Hubbard model. Through our methodological refinement of FRG both within its N-patch and truncated unity formulation, we resolve previous discrepancies of different FRG approaches [Wang et al., Phys. Rev. B 87, 115135 (2013)1098-012110.1103/PhysRevB.87.115135 vs Kiesel et al., Phys. Rev. Lett. 110, 126405 (2013)0031-900710.1103/PhysRevLett.110.126405], and analyze both the pure (p-type) and mixed (m-type) van Hove fillings of the kagome lattice.