Stabilizing topological superfluidity of lattice fermions

Attractive interaction between spinless fermions in a two-dimensional lattice drives the formation of topological superfluid. But phase is dynamically unstable towards separation when system has high density states and large strength. This limits critical temperature to an experimentally challenging regime where, for example, even ultracold atoms molecules optical lattices would struggle realize We propose that introduction weaker longer-range repulsion, addition short-range attraction fermions, will suppress instability. Taking honeycomb as we use unrestricted Hartree-Fock approximation show our proposal significantly enlarges stable portion superfluid increases by order magnitude. Our work opens route enhance stability superfluids engineering interparticle interactions.