Quantum Monte Carlo study of the Hubbard model with next-nearest-neighbor hopping <i>t</i> ′: pairing and magnetism

Abstract Using the finite-temperature determinant quantum Monte Carlo (DQMC) algorithm, we study the pairing symmetries of the Hubbard Hamiltonian with next-nearest-neighbor (NNN) hopping t ′ on square lattices. By varying the value of t ′, we find that the d -wave pairing is suppressed by the onset of t ′, while the p + i p -wave pairing tends to emerge for low electron density and t ′ around −0.7. Together with the calculation of the anti-ferromagnetic and ferromagnetic spin correlation function, we explore the relationship between anti-ferromagnetic order and the d -wave pairing symmetry, and the relationship between ferromagnetic order and the p + i p -wave pairing symmetry. Our results may be useful for the exploration of the mechanism of the electron pairing symmetries, and for the realization of the exotic p + i p -wave superconductivity.