Effect of dipole-dipole interaction on unpolarized ultracold fermionic gases in a two-dimensional optical lattice

We study effects of the dipole-dipole interaction on fermionic cold atomic gases in two-dimensional optical lattice. We calculate spin and density correlation functions within the random-phase approximation. It is shown that the spin-correlation functions of spin components perpendicular to the lattice plane show a characteristic peak structure different from that of the parallel component. We study s-wave and d-wave superfluidity induced by the spin and density correlations and show that the dipole-dipole interaction assists the d-wave superfluidity.