p-wave chiral superfluidity from an s-wave interacting atomic Fermi gas

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Chiral p-wave superfluids are fascinating topological quantum states of matter that have been found in the liquid ³He-A phase and arguably in the electronic Sr₂RuO₄ superconductor. They are shown fundamentally related to the fractional 5/2 quantum Hall state which supports fractional exotic excitations. A common understanding is that such states require spin-triplet pairing of fermions due to p-wave interaction. Here we report by controlled theoretical approximation that a center-of-mass Wannier p-wave chiral superfluid state can arise from spin-singlet pairing for an s-wave interacting atomic Fermi gas in an optical lattice. Despite a conceptually different origin, it shows topological properties similar to the conventional chiral p-wave state. These include a non-zero Chern number and the appearance of chiral fermionic zero modes bounded to domain walls. Several signature quantities are calculated for the cold atom experimental condition.