  We investigate the metal-insulator transition (MIT) and phase diagram of the
half-filled Fermi Hubbard model with Rashba-type spin-orbit coupling (SOC) on a
square optical lattice. The interplay between the atomic interactions and SOC
results in distinctive features of the MIT. Significantly, in addition to the
diverse spin ordered phases, a nonmagnetic insulating phase emerges in a
considerably large regime of parameters near the Mott transition. This phase
has a finite single-particle gap but vanishing magnetization and spin
correlation exhibits a power-law scaling, suggesting a potential algebraic
spin-liquid ground state. These results are confirmed by the non-perturbative
cluster dynamical mean-field theory.
