Multiband-driven superfluid-insulator transition of fermionic atoms in optical lattices:A dynamical mean-field-theory study

摘要

The superfluid-insulator transition of fermionic atoms in optical lattices is investigated by two-site dynami-cal mean-field theory. It is shown that the Mott transition occurs as a result of multiband effects. The quasi-particle weight in the superfluid state decreases significantly as the system approaches the Mott transition point. By changing the interaction and the orbital splitting, we obtain the phase diagram at half filling. The numerical results are discussed in comparison with. the effective boson model.