Robustness of flat band superconductivity against disorder in a two-dimensional Lieb lattice model

The possibility of achieving high-temperature superconductivity in flat-band materials causes a great deal of excitement in the condensed matter community. As the synthesis of real materials inevitably leads to the presence of an unavoidable amount of defects, the authors explore the robustness of flat-band superconductivity in the face of disorder. They reveal in this letter that, unlike conventional intraband superconductivity for which disorder has a dramatic impact, flat-band superconductivity is surprisingly resilient to disorder-induced fluctuations and quasiparticle localization.