Unconventional superconductivity near a flat band in organic and organometallic materials

Abstract

We study electron correlation driven superconductivity on a decorated honeycomb lattice (DHL), which has a low-energy flat band. On doping, we find singlet superconductivity with extended-s, extended-d and f -wave symmetry mediated by magnetic exchange. f -wave singlet pairing is enabled by the lattice decoration. The critical temperature is predicted to be significantly higher than on similar lattices lacking flat bands. We discuss how high-temperature superconductivity could be realized in the DHL materials such as Rb 3 TT • 2 H 2 O and Mo3S7(dmit)3.