Sublattice interference in the kagome Hubbard model

We study the electronic phases of the kagome Hubbard model (KHM) in the weak-coupling limit around Van Hove filling. Through an analytic renormalization group analysis, we find that there exists a sublattice interference mechanism where the kagome sublattice structure affects the character of the Fermi surface instabilities. It leads to major suppression of T-c for d + id superconductivity in the KHM and causes an anomalous increase of T-c upon addition of longer-range Hubbard interactions. We conjecture that the suppression of conventional Fermi liquid instabilities makes the KHM a prototype candidate for hosting exotic electronic states of matter at intermediate coupling.