Variational monte carlo study for superconductivity in multi-orbital systems

Abstract

To understand the mechanism of superconductivity in iron-based superconductors in a minimal model, we have studied the two-orbital Hubbard model in a two-dimensional square lattice with variational Monte Carlo method. We have found that the s+- wave symmetry, where the gap function changes its sign between hole and electron pockets, is favored among the various pairing symmetries. We have also discussed the mechanism of the s+- wave superconductivity. © Published under licence by IOP Publishing Ltd.