Competing Orders in the 2D Half-Filled SU(2N) Hubbard Model through the Pinning-Field Quantum Monte Carlo Simulations

We nonperturbatively investigate the ground state magnetic properties of the 2D half-filled SU(2N) Hubbard model in the square lattice by using the projector determinant quantum Monte Carlo simulations combined with the method of local pinning fields. Long-range Neel orders are found for both the SU(4) and SU(6) cases at small and intermediate values of U. In both cases, the long-range Neel moments exhibit nonmonotonic behavior with respect to U, which first grow and then drop as U increases. This result is fundamentally different from the SU(2) case in which the Neel moments increase monotonically and saturate. In the SU(6) case, a transition to the columnar dimer phase is found in the strong interaction regime.