1207.6843 (Zi Cai et al.)

Quantum magnetic properties of the SU(2N) Hubbard model in the square
lattice: a quantum Monte Carlo study    [PDF]

Zi Cai, Hsiang-Hsuan Hung, Lei Wang, Yi Li, Congjun Wu

We employ the determinant projector quantum Monte-Carlo method to investigate the ground state magnetic properties in the Mott insulating states of the half-filled SU(4) and SU(6) Fermi-Hubbard model in the 2D square lattice, which is free of the sign problem. The long-range antiferromagnetic Neel order is found for the SU(4) case with a small residual spin moment. The SU(6) case is a spin gapless quantum paramagnetic state with the absence of long-range antiferromagnetic, dimer, and charge flux orderings. Spin correlations exhibit power-law decay, which is consistent with a possible algebraic spin-correlation state with an odd number of fermions per unit cell.

View original: http://arxiv.org/abs/1207.6843