Constrained-path quantum Monte Carlo simulations of the Kagome-lattice Hubbard model show that the dominant superconducting pairing symmetry is set by the interplay of on-site (U) and nearest-neighbor (V) Coulomb interactions. With only on-site U, next-nearest-neighbor d-wave pairing dominates near the Dirac-point filling; introducing an attractive nearest-neighbor interaction V drives a crossover to nearest-neighbor p-wave pairing. This gives an unbiased numerical route to identifying the pairing symmetry debated in the AV3Sb5 family of Kagome superconductors.
The Kagome-lattice Hubbard model places interacting electrons on a Kagome lattice, a frustrated network of corner-sharing triangles whose tight-binding spectrum contains two Dirac cones and a flat ba…