Magnetic Phases of Fermionic Atoms Confined in 1-D Optical Superlattice

We study the ground state of alkaline-earth fermionic atoms confined in a one-dimensional optical superlattice, when the number of delocalized atoms is one-fourth the number of system sites. We used the density matrix renormalization group method and found a paramagnetic to ferromagnetic quantum phase transition for any value of the potential strength. The local critical antiferromagnetic coupling decreases as the superlattice potential increases.