We simulate the experimental possibility of observing the antiferromagnetic (AF) order in the bosonic mixtures of rubidium ($^{ 87}$Rb) and potassium ($^{ 41}$K) in a two-dimensional optical lattice in the presence of harmonic confinement. By tuning the interspecies interactions and the lattice heights we have found the ground states, within the mean-field approximation, that interpolate from the phase separation to the AF order. For a moderate lattice height the coexistence of the Mott and AF phase is possible for the Rb atoms while the K atoms remain in the AF-superfluid phase. This observation may provide an experimental feasibility to hitherto unobserved AF order for $^{ 87}$Rb - $^{ 41}$K mixture.
Categories: cond-mat.quant-gas quant-ph